Is a non-Muslim allowed to make Dua?

Question: A friends family member has passed and I was asked to make Dua. I'm not Muslim so I looked it up but am I allowed to do so? I didn't want to be rude and reject without knowing for sure.
Comment: As per Islam all of us have same God. Dua means prayer. It is a personal act between you and God. You do not need anybody's permission for it. So the idea of it being allowed or not allowed does not arise.
Comment: Obviously, anyone can make dua until he/she believes in God. I mean, if one doesn't believe in God then whom is he/she making Dua to..??
Answer: Anyone can make dua, disbelieving/non muslim satan (ibliz) made a dua to reprieve him till day of judgement.  Allah accepted his dua.
dua is accepted from non muslims, with following conditions 1. Sincerity 2. He should ask justful thing, (let me win 1 million lottery is not justful dua)
Comment: Thank you so much!!
Answer: Yes. You can. It's so nice of you to do so.
Comment: This answer is entirely opinion based. Please provide facts and references that support your answer. Nonetheless, once you have sufficient reputation you will be able to comment on any post.
Answer: In contrast to Salat, Dua is a free form of praying that is not specific to Islam; Christians and Jews and other religions who pray to God also know free forms of prayer which are not necessaryly different from Dua of Muslim. If Christians pray to God (not Jesus or Mary or someone else), it may also be shared. At least, we already did so; it may not be common everywhere.
Someone who does not believe in God may stay present if others are praying; he may accept to be included in Dua but should not pretend to pray.

Is a non-Muslim allowed to make Dua?


Getting BTT filament sensor to work

Question: (This is a pretty much duplicate post from one I put over on the Reddit, but it hasn't received a lot of traction over there so I figured I'd post):
Like many posts I've seen on the internet, I'm having trouble getting my BTT smart filament sensor to work.
Relevant Specs about my printer:

Ender 3 Pro
BTT E3 RRF Mainboard with IDEX module
Marlin Firmware I've edited in ways I mention below

What is going wrong:
It triggers way too easily.  Right as a print starts, it'll trigger and say I ran out of filament.  And/or it'll make it maybe half a layer and then trigger.
Steps I've taken:

I started by following the Teaching Tech YouTube video to get started and install it. Tried to match literally every change of his in the firmware I saw.  Things like runout distance set to 7 and runout state set to low instead of high.

Quick note on those.  In several places (like this) comments suggest changing the distance to more than 7 mm to make it less 'picky'.  But in several comments (like here, and here), people suggest the official recommendation from BTT is 7 mm and there's a reason to set it at that.   I've tried all sorts of distances and none seem to work.
In at least one place (like here) people suggest that even if you set it to 7 mm in the firmware, it doesn't always take effect and you have to go to the configuration menu in your printer and set it, then store the settings.  I've done that as well.
I've set the runout state to either low or high, seems to still falsely trigger either way.

The only solution I haven't tried yet (will try tonight when I get home)  (did that , still no luck) is in this comment it suggests adding M75 to my code to 'start the print job timer' so it won't trip 'after the initial 7 mm runout'.  Could someone explain that one to me?  Also, I feel like that's not it because even when I let it go through its paces and unload and then load, it'll trip again soon after.

The problem:
I just feel like it's still way too sensitive.  And sure, in an ideal world I want it to detect all the things it's 'supposed' to detect like jams, tangles, etc...   but I really just care the most about it noticing I ran out of filament.
Are there any settings in the firmware or anywhere else I should take a look at?
My latest thought is that maybe I have the sensor mounted in a different direction than it should be?  Every video or picture I see online looks like the filament is going the opposite direction compared to what I have, but I've also seen comments where it says that doesn't matter.
I also have seen comments like here where the author recommends a HUGE runout distance (50) as that could be a problem. I'm willing to try that.
Answer: I would comment but I don't have enough reputation yet -
Are you using the Creality firmware, Marlin, RepRap, or the Stock BIGTREE firmware? Also, have you modified it at all?
If you're still using the firmware that came on the printer or Marlin firmware this thread could offer some insight. Read down through all of the comments because several people had really good tips, and the OP actually posted an update with how he solved it:

It seems that the settings stored in the printer overwrides the  FILAMENT_RUNOUT_DISTANCE_MM  in the firmware. So I just went the the printer configuration -> advance configuration -> filament and then I changed the runout distance and stored the settings. Source
Comment: I have marlin.  I mentioned that "that even if you set it to 7 mm in the firmware, it doesn't always take effect and you have to go to the configuration menu in your printer and set it, then store the settings. I've done that as well"

Getting BTT filament sensor to work


Is it better to use one data transform or many?

Question: We're essentially bulk loading data from one database to another, using SSIS.  My co-worker has made one data transform object, and within it, he has a transform for each table.  I've made a transform object for each table.  We're both rather new to SSIS.  Is one way better than the other?  What are advantages or disadvantages to each method?
Answer: With one data transform object can you readily (re)load just one table?
Data migration exercises don't always work first time. If you need to experiment, adapt and retry a portion then finer granularity of control may be very helpful. Down side of fine granularity is that you have more pieces to manage.
Answer: If you meant, multiple data flows inside a Data flow task (case A) and multiple data flow tasks to handle different table (case B),  the performance will be somewhat the same, if you allow them to execute in parallel. But if you want to consider other things such as error handling, package restartability and all I recommend case B. Because SSIS does not support restartability inside data flow task. And it will be better if you take a look at the SSIS architecture, synchronous and blocking transformations, etc before you decide.
Comment: That is what I meant, and I will look at those links.  Thank you.


Is it possible to talk to bitcoin RPC API with Javascript and WITHOUT using a node server?

Question: I am planning on building a Wallet and want to know if I can hook something like an Electron native JavaScript app to Bitcoin RPC without running node.js for the server calls, so using something like AJAX or XMLhttprequest.
Answer: It is possible? Yes definitely!
Is it secure and smart to do? NO!
Anyone can see the password of your bitcoin node and thus steal your funds.
You will be hacked in no time.


Affine bundles over varieties

Question: Let $\mathbb{A}^n_k$ be the Affine $n$-space over an algebraically closed field $k$.
Let $X$ be a variety over $k$. What would be the right definition of an "Affine bundle" i.e bundle of fiber type $\mathbb{A}^n_k$ over $X$ (I mean local triviality in zarisky topology,or
etale .. )?. When can one get a vector bundle from an "Affine bundle" , more
precisely (I think !) if I assume the structure group of the affine bundle to
be $Aut_{Var_k}(\mathbb{A}^n_k)$, when can one get a reduction of the structure group
to $GL_n(k)$?
Comment: Well it's a $X$-scheme which locally on $X$ looks like $A^n \times X$. It's almost the same as a vector bundle, because in a vector bundle the linear structure belongs to the data.
Answer: I think the term "affine bundle" is used for at least two things: (1) A map $p:Y\to X$ such that for some open cover (in your choice of topology) there are isomorphisms $p^{-1}(U)={\Bbb A}^n \times U$ --- just like you said. (2) A torsor for a vector bundle, i.e., like (1) but with the added condition that the transition functions are affine-linear.
In the situation of (2), it's a vector bundle exactly when there's a section  (like any torsor).  A simple non-vector-bundle-example is the complement of the diagonal in ${\Bbb P}^1 \times {\Bbb P}^1$, projecting onto one of the factors.
For (1), I don't know any general (non-trivial) criterion for such a thing to be a vector bundle.  (Maybe because the group $Aut({\Bbb A}^n)$ is so complicated...)  A simple non-example is the 2nd-order jet scheme $\mathrm{Hom}(\mathrm{Spec}(k[t]/(t^3)),{\Bbb P}^1) \to {\Bbb P}^1$.  The fibers are ${\Bbb A}^2$, and there's a section, but it's not linear.  I suppose one test is whether the sheaf of $O_X$-algebras $p_*O_Y$ admits a grading generated in degree one.  (This fails for the jet schemes, though there is a natural grading by scaling $t$.)
Comment: I agree with AByer on common usage. The other useful test is that, given a vector bundle $V$, the torsors for $V$ are classified by $H^1(X, V)$. For example (exercise!), in the $\mathbb{P}^1 \times \mathbb{P}^1$ example, the vector bundle is $\mathcal{O}(-2)$ and the affine bundle Dave gives corresponds to a nontrivial element of $H^1(X, \mathcal{O}(-2)) \cong k$.
Comment: Just as an additional data point, I think have only seen the meaning (2).
Comment: I prefer (2) as well, but Fulton's *Intersection Theory* uses (1) -- and it seems others (e.g. Georges!) do as well.
Comment:  Dear Dave, no, no, I'm with you , AByer and David on prefering (2) and that is what I mean with my notation  $Aff_n(k)$   . I'm sorry that my post was ambiguous on this point : I've just edited it and adopted your excellent terminology "affine-linear". It is amusing that you mention Fulton: his meaning (1) for "affine bundle" had also struck me as unusual, but on the other hand it makes more general his surjectivity theorem for the morphism of Chow groups induced by the projection of an affine bundle .
Answer: Dear rvk, as you and Dave said, an affine bundle is a morphism $p:Y\to X$ such that for some open cover $(U_i)$ of $X$ there are isomorphisms $p^{-1}(U_i) \simeq {\Bbb A}^n \times U_i$.
 However the question arises: a cover for what topology? $\:$ In the cases you evoke, étale and Zariski, I am happy to report that it doesn't matter in the case of
affine-linear transition functions.
In other words  an affine bundle locally trivial in the étale topology is already locally trivial in the Zariski topology. The reason is that the affine group $Aff_n (k)$ is "special" in the terminology introduced by Serre here. Serre first proves that  $GL_n(k)$ is special (Théorème 2) and then that an extension of a special group by a special group is special (Lemme 6). The specialness  of  $Aff_n (k)$ (which he doesn't mention) then follows easily from (Proposition 14).
Remark 1: It is difficult to overestimate the importance of Serre's article. It might be considered the birth certificate of étale topology under the guise of "fibrés localement isotriviaux".
Remark 2 :  Groups are rarely special ( Serre knows what words mean!) . For example  $PGL_N(k)$ is  not special and so  bundles with typical fiber $\mathbb P^n$ which are locally trivial in the étale topology needn't be locally trivial in the Zariski topology. This is the subject of Brauer groups of schemes, as envisioned by Grothendieck.
Comment: Thanks for this! (I hadn't known all solvable groups were special -- only thinking of the classification for semisimple ones, I forgot not every group is semisimple...)
Comment: Dear Georges: I have a few times decided to try to understand what the Brauer group is, but not even grasped the definition of an Azumaya algebra. Your last remark makes the whole thing sound very reasonable and geometric -- could you perhaps say a few words about what $\mathrm{PGL}_n$-torsors have to do with the Brauer group, or recommend a readable reference?
Comment: Dan, if you will accept an interruption, my own recommendation would be the first parts of Deligne's Arcata lectures in SGA4 1/2.
Comment: Dear Dan, my favourite reference is without doubt Gille and Szamuely's  book [1] Central Simple Algebras And Galois Cohomology. It is written in a very user-friendly style and I think you can fairly quickly jump to Chapter 5, where Severi-Brauer schemes are introduced and linked to $PGL_n(k)$ .

[1]; http://books.google.fr/books?id=HFsxkvLtl_QC&printsec=frontcover&dq=szamuely+gille&source=bl&ots=OAGnhpuZlU&sig=OeIQ_BMb1dILHJnHrhwg1LzhMw8&hl=fr&ei=miNPTcjoLMm3hAfQp4z_Dg&sa=X&oi=book_result&ct=result&resnum=4&ved=0CC0Q6AEwAw#v=onepage&q&f=false

(to be continued)
Comment: (continuation) There is also a a nice survey by Jahnel of these questions  that you can  find here:

http://www.uni-math.gwdg.de/jahnel/Arbeiten/Bpal.pdf
Answer: The very interesting paper  "Locally polynomial algebras are symmetric algebras, Invent. Math. 38 (1976/77), no. 3, 279–299. MR 0432626 (55 #5613), by H. Bass, E. H. Connell, and D. L. Wright, gives some answers to this question. It says that if everybody is affine and the bundle is locally trivial in the Zariski-topology, then it is a vector bundle.

Affine bundles over varieties


Unlocking iPhone 5s

Question: My sister had locked her phone by downloading the IOS 8 and in the process she had turned off her phone. Her whole phone had then locked out and started over. Logically, we would take  the phone and put in the iCloud account with the iCloud email and password but the problem is she does not know her password so we went to recover it but she keeps getting the security questions wrong and she forgot what email she used to recover the iCloud account. I´d really appreciate any help. Thank you.
Answer: Locked is locked, that's the whole idea.
If https://iforgot.apple.com doesn't help, then next would be to phone Apple & see if they can help. Apple Support phone number list, by country

Unlocking iPhone 5s


What are Dragons most vulnerable to?

Question: In Skyrim, What type of magic are Dragons most vulnerable. I know it's not fire. Is it more effective to use frost, spark, or a power other than destruction when battling Dragons?
Answer: Dragons are vulnerable to fire: well, at least some of them.
There are many types of dragons, but they fall into two major archetypes: fire dragons and frost dragons.

Fire dragons are vulnerable to frost (25% weakness) but resistant to fire (50% resistance).
Frost dragons are vulnerable to fire (25% weakness) but resistant to frost (50% resistance).

So if you're trying fire and it's not doing a lot of damage, switch to frost. But you should be able to tell what type of dragon it is by the type of breath attack it has.
Answer: Yes, all dragons can be hurt by fire. After all, if think about it, they are magical creatures and well, it's destructive magic.
Not to mention, some dragons can be more hurt by fire than others. It's just common sense that a dragon with ice breath wouldn't like fire, whereas a fire dragon would dislike the cold.
So the above answer is pretty good and does outline which magics work hurt what types of dragons.
However, there is a second part to this question that I don't feel got answered.

"What magic is most effective against dragons?"

While fire and ice magic does have hit power, it's not always the best approach. Dragons can show up without notice, and skyrim has a diverse climate. There are times where both a fire and ice dragon can appear.
At such times, it's not always practical to cast the typical fire/ice magic.
This is why I go for shock magic. It works the same against each type, allowing me to more fully prepare for sudden attacks. I like to temper this with healing magic, so that I don't have to pop potions every time I get low.
That way, I'm self sustaining. Dragon shows up? I'm ready. Even if my magic regen is low, as long as I can get cover, I can keep healing. It works wonders, even at lower levels.
Answer: The other answers are all great, but it still takes too long to kill them that way. What I use is the first level Marked for Death shout found in the dark brotherhood sancurary. Since its recharge time is short, you can use it 3-4 times and their heal drop by a lot. Even works on Elder and Ancient dragons. By using a 105 bow, I was only able to take out 1mm of health, but using the shout a few times, my bow can take out an ancient dragon with only 5-6+ hits with a 105 ebony bow.
Answer: Definitely use Shock against dragons. A flying creature that gets struck with lightning either dies or stops flying; then I can just start use poisons to weaken them even further (for example, weakness to fire... or shock) plus enchanted daggers and shouts (try the ice shout). (Note Class: "Sneaky Gandalf").
Shock plus posion (weakness, Parylisis, Ebonyskin & Dragonhide) plus magicka immunity plus magicka regeneration at 250% gives you a dead Alduin on expert.
Comment: magicka regen is a thing of the past when you can have 100% magicka spell cost reduction
Answer: i think that the most powerful spell against a dragon is the oppisite of what type the dragon is for example:
fire dragon is most vulnerable to ice and frost spells
frost dragon is most vulnerable to fire and flames
Answer: Of note is that dragons use their Magicka pool for shouts(all dragons have 150 Magicka). If you can manage to keep their pool of Magicka continually depleted through the use of shock spells, they cannot shout at your or anyone else. Dual Casting and Impact help with this. Before you have damaged their pool enough to prevent them from shouting, the stagger effect from Dual Casting can also prevent them from managing to get out a shout. Another plus for shock based spells compared to the other elements is that it hits your target instantly. It can be very hard to hit flying dragons with fire or ice spells, but it is relatively very easy to hit them with shock spells.
Comment: This doesn't really add anything new - other answers have already mentioned using lightning to reduce the dragon's magicka
Comment: I admit to not reading all the other answers super close before posting this one, but after a much closer reread of every answer plus comments I see nothing regarding that part of my answer. Care to give me a specific example? Also, while I saw the use of shock as just sort of a general response I see nothing regarding a type of spell's ability to hit the dragon versus another spell type. I avoided including anything about fire and frost because they've already been mentioned repeatedly and I didn't want to be redundant. This actually adds new useful info about using shock to the answers.
Answer: I found having a daedria lord that you can conjure can do very well when they hit the ground. there damage is very effective, and if you have a high enough lv in conjuring you can summon 2 of them. summoning 2 of these guys will draw the dragons attention and you just sit back with a bow and shot them... or having a 2 storm atronach for long range is also affective..

What are Dragons most vulnerable to?


Get the raw binary stream from an optical fiber

Question: How get the raw binary stream from a fiber ?
Assuming we have a SFP (ethernet, FC, GPON, other), this transceiver is not protocol independant, and will treat and interpret the binary stream received following the protocol design it implement, then transmit the binary flow corrected and treated to the upper layers.
Do a classical transceiver could get and display the raw binary stream received ? (I doubt about this)
In this case, how can we get the binary stream of an optical fiber ?
Answer: The optical signal is a binary stream. I assume you mean to diagnose the equivalent electrical signal.
SFP transceivers are ignorant to the actual L1 protocol in use. Their main job is to convert an electrical signal (e.g. 1000BASE-X) to an optical signal (1000BASE-SX) and vice versa. You could use the TD+/- and RD+/- pins to extract the raw, differential signals (see INF-8074i at snia.org for details). Those signals are still PCS and PMA encoded.
If you're trying to run a transceiver in stand-alone mode, without a suitable device slot, you'll need to make sure that the protocol is initialized correctly which may not be trivial (in addition to the xcvr initialization, obviously). In a PON environment you must make sure that the transmitter side is only active in its allocated time slot.
Comment: https://datasheets.maximintegrated.com/en/ds/MAX3748.pdf (3795 driver) There are slight enough differences that manufacturers only mark them for how they were tested. An ethernet SFP *might* work for FC or SONET, but also might not. (plus the greedier scum like to brand their optics, even when they are purely outsourced commodity parts)
Comment: @bdes31 The difference is the device with the SFP slot. The xcvr has a bit of memory (I2C EEPROM) where its compatibility etc is recorded (see section B4 in INF-8074i). Using that, a device can accept or reject a module in a certain port for a certain protocol. The module itself doesn't care.
Comment: @bdes31 I was referring to PCS and PMA as these are the prevalent sublayers in on-topic devices here. Note that an SFP module is not much more than the PMD - all encoding is done in the switch/router/NIC. The splitter should work, provided you find a suitable SFP module (wavelength/speed) for reception.
Comment: Thanks for the reply.
You say "SFP transceivers are ignorant to the actual L1 protocol in use", why we could find Ethernet SFP, GPON SFP, FC SFP, or others SFP, if SFP transceiver are ignorant to layer 1 protocol ?
Good idea for the TD+/- and RD+/- pins for the extraction. PCS and PMA are Ethernet standard, so it's not "totally" ignorant to layer 1 protocol ?
Finally, my use case: using a 1:2 optical splitter to split GPON upstream signal to two fibers, 1 fiber to the OLT, and second fiber for the binary stream extraction we are discussing.


the real advantage of Heroku or Engine Yard?

Question: I've ready some posts regarding the Heroku or Engine Yard for Rails3. When I look at their price, they are pricey comparing to a regular VPS or even a entry dedicated server. Besides flexible billing and easy vertical scaling, what are real advantage of using them? If I have ability to maintain the server. Thanks.
Comment: possible duplicate of [What are the advantages and the pitfalls of specialized rails hosting services?](http://stackoverflow.com/questions/2164074/what-are-the-advantages-and-the-pitfalls-of-specialized-rails-hosting-services)
Answer: For me, the advantage is speed and simplicity.
Since I just want to focus on my apps, it's a convenience to have a managed platform that I can quickly push application to. This relieves the up-front headache of setting up a server, DB, managing URLs, etc...
Yes, they're more pricey, but that's the price you pay for the convenience of not having to deal with servers. If you want to put together a site in 10sec, you can. (Check out Toto: https://github.com/cloudhead/toto)
Another very nice feature of these PAAS companies is that they offer out-of-the-box support for many different setups. Different versions of rails are all supported.
Heroku seems to be more focused on total convenience, while Engine Yard functions more like a service that sets up servers for you that you can work on yourself. (I've not used Engine Yard for production apps, only tested them out. Please correct me if I'm wrong...)
Heroku also offers plugins, which further simplify things like mailservers, backups, logging, etc...
If you're looking for long-term cheapness, yes, look elsewhere. There are a lot of really good solutions available. But that's just not the target market for these companies.
Loren


Cannot login to WP after force recovery

Question: I recently had an issue on my locally placed site with Mamp. I resolved it through a force recovery with some tech help. The Mysql server came back on after doing the force recovery however now I am unable to login into my wordpress site. I believe it may be something to do with the myphp.admin but could be completely wrong. I'm in way over my head at this point so could use some help.
Comment: Looks like I may have figured this out by removing the force recovery from my.cnf and saving. I also went to myphp.admin and did arepair of all the tables. Not sure which was the reason to being able to login now. However with that said I am still getting this error on mysql: Error: Table "mysql"."innodb_table_stats" not found.
Answer: I am assuming that you have access to the WP database (via your hosting phpMyAdmin), and that you can't recover you login via the 'lost password' thing.
I also assume that you can access the pages of the site (the non-admin pages).
So, it would appear that you need to recreate your admin user in the WP database. This page (among others found via the googles) will help you recreate the admin user http://www.inmotionhosting.com/support/edu/wordpress/333-add-admin-via-mysql .
If your user already exists in the database, then you may just need to reset the password, again through using phpMyAdmin through your hosting account.

Cannot login to WP after force recovery


How to set the default domain for a new Roundcube webmail user?

Question: New Roundcube identities get a '@localhost' domain part for their Email address. That is kind of useless. I would rather have Roundcube take the Apache HTTP host (minus a possible 'www.'), since my users will use 'their' associated domain for getting to the Roundcube interface. How can I configure this?
Answer: Found the solution to my problem. In the main config of roundcube (/var/lib/roundcube/config/main.inc.php) you can set the mail_domain variable:
$rcmail_config['mail_domain'] = '%d';

There are multiple placeholders, but %d will use the web server domain, which is fine for me.
Comment: In the current version (1.1.3), it would be `$config['mail_domain'] = '%d';` in the file `roundcube/config/config.inc.php`.
Answer: Look here:
    grep -nR -B9 mail_domain defaults.inc.php
    440-
    441-// This domain will be used to form e-mail addresses of new users
    442-// Specify an array with 'host' => 'domain' values to support multiple hosts
    443-// Supported replacement variables:
    444-// %h - user's IMAP hostname
    445-// %n - http hostname ($_SERVER['SERVER_NAME'])
    446-// %d - domain (http hostname without the first part)
    447-// %z - IMAP domain (IMAP hostname without the first part)
    448-// For example %n = mail.domain.tld, %t = domain.tld
    449:$config['mail_domain'] = '';

So, you could add
$config['mail_domain'] = '%d';

to your roundcube/config/config.inc.php file. (not to the defaults.inc.php file which may be overwritten by upgrades)
Answer: In "WHM Home » Server Configuration » Tweak Settings", under the "Mail" tab, you can disable the other Webmail clients by ensuring the following options are not selected:
"Enable Horde Webmail"
"Enable SquirrelMail webmail"
Or you can directly login using the below URLS:
server:2095/3rdparty/roundcube/
server:2096/3rdparty/roundcube/
If proxy sub-domains are enabled, the following URLs, using the "webmail." sub-domain, will also go directly to Roundcube; replace "domain" with your cPanel account domain name:
webmail.domain:2095/3rdparty/roundcube/
webmail.domain:2096/3rdparty/roundcube/
Comment: The OP didn't say anything about cPanel.
Answer: this is an old thread but you should be able to set the server name using this command
dpkg-reconfigure roundcube-core

In my case I have isp3config, my server is set up as debian.example.com, my two sites are example.com and example.net.
When it asks for the server name I put in debian.example.com, if you leave it blank it will ask you the server on the log in page.


Is it common to have one sore hangstring / IT band?

Question: I've been running for years and only my left IT band has been sore lately. No recent injuries (rolled my last ankle something good 7 months ago) and haven't added any additional mileage lately. I would expect both legs to tire evenly. Is it uncommon to experience this from running?
Answer: I know that my most frequent running injury was my right hip. Never had a problem with my left side at all.
I think you usually end up injuring one side early in life, then compensate or lose flexibility somehow, then start developing imbalances. I'm a huge barbell fan, but bodyweight single-left stuff is awesome for identifying imbalances.
I would imagine every human being that masters the pistol squat had to spend a lot of time dealing with the differences between both legs. I was able to knock out ~10 on my right side and could barely do ~3 on my other, before I started really going after the imbalances.


Why won't the Boethiah cultist die?

Question: On PS4, I started the Boethiah's Calling quest at level 27 and killed all of the cultists except one. This one, in particular, won't take damage and knocks my follower every time I try to go to the pillar. I gave up and did other quests. I'm now level 43 and the cultist still doesn't take any damage.
Answer: As per the UESP Wiki article on Boethiah's Calling:

If you kill the priestess before talking to Boethiah, one or two of
  the current fighters may become unkillable.

You'd have to load a save where the priestess hasn't been killed yet. And then don't kill her before talking to Boethiah.
If playing on the PC, you can use console commands to fix the issue:

Open the console and for each fighter that's unkillable, click on them and then type
  kill. The quest will proceed as normal once all the fighters are dead.
  If that does not work, open the console and type damageactorvalue health 500.
Answer: Since you cant use console commands, I found that you can potentially bypass this issue by carefully sneaking aroung back from the mountains to the right. Sneakily sacrifice a follower (by making them interact with the pole) and kill them with the sacrificial knife. Hurry the conversation, he may aggro, but after she says to fight, he should be damagable again.
If this doesnt help now, hopefully it can help future sons of Skyrim.
Answer: The answer by user272187 works like a charm, I will contribute with more details on how to apply it.
I had the exact same issue as the OP and to make things worse I was using a mage build, so the cultist could kill me in about 3 hits making it very hard to not get killed while talking to Boethiah.
The steps are:

Quicksave before reaching the Sacellum of Boethiah so you can retry the steps in case something goes wrong.
Sneak through the rocks on the right side of the area and reach the bottom of the altar next to a tent.
Hug the wall at the bottom of the altar to reach the steps without being heard/seen.
Make the follower interact with the pillar of sacrifice.
When the follower is trapped go down the steps and summon one or more creatures to distract the Cultist and give you more time to finish the conversation.
Kill the follower (any death will do, no need for the sacrificial dagger).

As soon as the conversation starts the cultist becomes mortal and depending on the summoned creature(s) they may even kill the cultist for you.
In my case, I summoned 2 Dremora Lords and they killed the cultist even before I could reply to Boethiah, making the quest automatically skip from Find the cult of Boethiah to Speak to Boethiah's Conduit
After that you should be able to finish the quest without problems.
Extra tips:

If you have low sneak you can increase the chances of not being detected by using the invisibility and muffle spells (alternatively, invisibility potion and boot with muffle)
By setting the quest as active you can see the cultist on the compass at all times as the Find the cult of Boethiah objective points to him.
If you don't have conjuration spells you can use scrolls.
Should be obvious, but don't summon any creature before the follower is trapped by the pillar otherwise they will attack the cultist and you will have to restart the process.

This saved my platinum trophy on the PS4 as the Ebony Mail is required for the Oblivion Walker achievement.

Why won’t the Boethiah cultist die?


Is there an iPod touch voice control app that can play music offline?

Question: I recently bought a 5th generation iPod touch, but was dismayed to learn that I can't use Siri to play music in my car because it doesn't work offline. Is there a voice control app that I can use to choose songs without a wifi connection?
Comment: If your phone is with you (you have iPhone tagged), create a personal hotspot with it, and use that to get your iPod the wifi connection it needs.
Comment: @Tyson Unfortunately, I don't, I just tagged it because the iPod touch uses the same apps as the iPhone. Should I take it off?
Answer: If you're willing to sacrifice Siri for the ability to control your music with your voice, you could turn off Siri in Settings>General>Siri, which'll make your iPod respond to a held-down Home button with the classic Voice Control interface instead. A Google search is telling me that that one works offline!
For more information about non-Siri Voice Control, check out Apple's support page. Here's what it says about music playback:

You can play all songs in an album, playlist, or by an artist. The device won't recognize commands to play a particular song.
If you can't get the device to recognize the album or artist name, try telling it to play a playlist.
If an artist has "The" in the name, say it.
Comment: Hmmmm..... that might work as a quick fix for me, but it's pretty unfortunate that you can't select a particular song. I know there's several voice control apps like Vokul, but I can't seem to confirm if any work offline.
Comment: @pocketlint You could always make one-song playlists.
Comment: Maybe, but then I have to think ahead to make playlists for each song, and I've got a pretty big library. Still, your solution is the best I've found, so thank you!


Creating new map

Question: Using Cartodb I copied a map to make a new one. The edits are being duplicated in both versions. Is there a way to restore the old map without impacting the new one?
Comment: When you "copied" what where the steps you did to do that? I am aware of a few options when working with maps on Cartodb. You can dupilcate, lock etc... Just trying to get more details as what you did to get where you are.
Answer: Duplicating maps should create independent maps in terms of styling, but they would still share the same source dataset.
Style changes (CartoCSS, queries applied on them, legends, elements...) should be independent, but if you are editing the data of one of your maps, take into account that you are really editing the data which lives in a dataset. Changing the data in a dataset, being it from the dataset instead or from different maps will show changes in all of them, as you are editing the underlying data.
If you need to edit the data independently, then you should create a copy of the dataset (with the Duplicate dataset option, for example) and create a map from it.

Creating new map


Is there a substantive difference in meaning when the Torah uses the Hebrew verb root דבר rather than אמר?

Question: Is there a substantive difference in meaning when the Torah uses the Hebrew verb root דבר rather than אמר, or do they both pretty much mean "to say" or "to speak"?  Do any sages see the choice of one word over another to have some extra meaning?
Comment: http://ottmall.com/mj_ht_arch/v25/mj_v25i93.html#CACN
Comment: @Danno  Sounds like a reasonable answer.
Comment: I have seen many explanations, but none that easily fit all cases. My best guess is dibbur relates to the act of speaking and amirah refers to what was said.
Answer: Many people tried to differentiate between "אמר" and "דבר".
There are several midrashim and a gemera in Makkos (11a) that identify דיבור as a "harsh" (קשה) way of speaking based on Gen. 42:30, and אמירה is "softer" (רכה). While some (including Torah Temima) take this literally to mean that דיבור and אמירה are different primarily in tone, others (N. H. Wessely, followed by Malbim) take this to mean a difference in style, where דיבור is much more elaborate and אמירה is is more get-to-the-point.
In HaPardes (No. 47, Vol. 9, pp. 24-25), Rabbi T. A. Sanders identifies some other qualities specific to "אמר" or "דבר". For example, דיבור is much more broad while אמירה is much more specific (similar to Wessely's distinction). אמירה is more impersonal, conveying a general sense of imparting information; it can be used for something said through a messenger or in writing; it can be used for something said to one's self or even in one's mind without actual verbalization. דיבור, on the other hand, is only used when there is a listener as well as a speaker.
Comment: The Gemara only says that Vayedaber is harsh (unless I missed something). The Torah Temimah you sourced led me to Rashi on Shemos 19:3 which is a good Mekor that Vayomer is soft.
Answer: The Midrash Rabbah (תשא פ' מב ופ' סח) and the Midrash Tanchuma (פר' צו) and the Sifri (פר' בהעלותך) teach that  "דיבור" is a harsh way of speaking, and "אמירה" is a soft way of speaking.
Comment: There's no Midrash Rabbah 68 in Ki Sissa or  Shemos Rabbah at all. The one in 42 only explains that Vayedaber is harsh but doesn't address Vayomer.
Answer: The Vilna Gaon in Aderes Eliyahu on the first verse in Ha'azinu says that וידבר is linked to Torah Shebichsav, and ויאמר is linked to Torah Sheb'al Peh.  He explains that this is why communication with Moshe is always with וידבר, and the only place where Hashem speaks to a Navi with וידבר is in reviewing a law from the Torah, when it reviews the laws of cities of refuge to Yehoshua (20:1).
The idea seems to be that דבר is a more direct communication than אמר (as the prophecy of Moshe was more direct than that of the Nevi'im after him).
Answer: R. Avraham b. haRambam writes in the beginnining of Va'Eirah (7:8):
לא ידעתי [מה החילוק] בין ויאמר לוידבר ולמה אמר פעם ויאמר ופעם וידבר ואם רק הוא מכם רק
"I do not know what's the difference between VaYomer and VaYedaber, and why sometimes the Torah uses one, and sometimes the other, and if it seems meaningless, it's your shortcoming."
Comment: You should translate and expand on this to make it a full answer. As of now it is just a comment
Comment: Is that it? Or does the statement continue with an answer? This only shows he had the same question ...
Answer: Just a thought. On the words of דַּבֵּר ׀ אֶל־בְּנֵי יִשְׂרָאֵל וְאָמַרְתָּ אֲלֵהֶם וְעָשׂוּ לָהֶם צִיצִת where Moshe is instructed to teach the commandment of tzitzis, both words are used in this pasuk.
As mentioned above, the Talmud Makkos (11a), Midrash Rabbah (תשא פ' מב ופ' סח) and the Midrash Tanchuma (פר' צו) and the Sifri (פר' בהעלותך) teach that "דיבור" is a harsh way of speaking, and "אמירה" is a soft way of speaking.
Based on this understanding, one could possibly say as follows: When conveying the Halachos of something, that are by their very nature rigid and strict, one could do so in a strict stern manner, like a drill sergeant in the army, or in a soft way like a caring parent would do for their child. The Torah is perhaps teaching us here that even strict rules need not be taught with strictness, but in a manner that portrays the Torah's value of kindness.
Answer: Based on Rashi, the general rule of scriptural interpretation is אֲמִירָה לְשׁוֹן רַכָּה. This means that words such as וַיֹּאמֶר denote gentleness. [See Rashi Shemos 19:3; Makkot 11a; Cf. Ben Yehoyada on Makkot 10b; Kli Yakar on Shemos 26:1] Rabbeinu Bachya says that this can be derived from the word אמרא, the edge of a cloak a person wears on his left side. [Similar to a paludamentum]
A verse that illustrates this symbolic idea of where G'd is depicted as wrapped in such a cloak, i.e. "עֹטֶה־אוֹר כַּשַּׂלְמָה - [You] enwrap Yourself with light like a garment." [Tehillim 104:2]. This represents מִידַּת הַדִּין - the attribute of Justice. (The act of wrapping it and covering it over the left side symbolizes the covering up of the attribute of Justice, which is on the left.)
On the other hand,  דִיבּוּר לְשׁוֹן קָשֶׁה - words such as וְַידַבֵּר, denote harshness. This can be derived from the word דְבוֹרָה - a bee. Although providing honey, i.e. sweetness, it also harbors a deadly sting. Nevertheless, the bee symbolizes the attribute of G-d that combines both the attribute of Mercy and the attribute of Justice. [Cf. Rabbeinu Bachya, Shemos Bo 13:1:4]
Answer: Since you mention the sages (or do you mean the Talmud?) wouldn´t it be better to consider the original root meaning (as indicated by their family usage in syntax) instead of trying to force biblical hebrew into modern mentality and usage?
אמר is "be precise", whereas דבר is "arrange, set in order". Their distinctive meaning and use is clear if you think like the original hebrew authors and readers.
That's why the idiom   דבר לאומר (he spoke, saying) occurs hundreds of times indicating a direct verbatim quote. A literalistic translation from the original root meaning would be "he arranged, to be precise, thusly:" or to put it in our modern mindset: "he said, and I quote, '...'".


What puts together composites according to Buddhism?

Question: I believe that the word for composite or compounded dharma is sankhara. What puts sankhara together, according to Theravada or Mahayana Buddhism?
I'd especially like an explanation that contrasts the answer to Hinduism.
Answer: The word 'sankhara' has many different meanings. It can mean:

"conditioned thing' (something made from causes & conditions; AN 3.134; Dhp 277; SN 22.90)
"conditioner' (a condition that conditions/creates another conditioned thing; SN 41.6; MN 44).
"conditioning" (the process of conditioning; SN 22.79)
aggregate of mental formations (sankhara khandha; SN 22.79; SN 22.48)
mental conditioning (i.e., mental proliferation, psychobabble or papanca; Dhp 203; SN 38.14).

Therefore what puts together a conditioned thing (sankhara; sankhata) is the conditioning (saṅkharonti) of other conditioned things (sankhara).
In the context of mental formations (sankhara khandha), SN 22.79 says:

Kiñca, bhikkhave, saṅkhāre [plural] vadetha?
And why do you call them 'fabrications'?
Saṅkhatamabhisaṅkharontīti kho, bhikkhave, tasmā 'saṅkhārā'ti vuccati.
Because they fabricate [saṅkharontī; verb] fabricated things
  [saṅkhatam], thus they are called 'fabrications'[saṅkhārā]
Kiñca saṅkhatamabhisaṅkharonti?
What do they fabricate [saṅkharonti] as fabricated thing [saṅkhatam]?
Rūpaṃ rūpattāya saṅkhatamabhisaṅkharonti, vedanaṃ vedanattāya
  saṅkhatamabhisaṅkharonti, saññaṃ saññattāya saṅkhatamabhisaṅkharonti,
  saṅkhāre saṅkhārattāya saṅkhatamabhisaṅkharonti, viññāṇaṃ viññāṇattāya
  saṅkhatamabhisaṅkharonti.
For the sake of form-ness, they fabricate form as a fabricated thing.
  For the sake of feeling-ness, they fabricate feeling as a fabricated
  thing. For the sake of perception-hood... For the sake of
  fabrication-hood... For the sake of consciousness-hood, they fabricate
  consciousness as a fabricated thing.
Saṅkhatamabhisaṅkharontīti kho, bhikkhave, tasmā 'saṅkhārā'ti vuccati.
Because they fabricate fabricated things, they are called
  fabrications.

In the context of intentional kamma (action), AN 3.23 says:

A certain person makes/generates/puts together
  (abhisaṅkharoti) hurtful (sabyābajjhaṃ) body
  choices/intentions/activities (kaya-sankhara), speech
  choices/intentions/activities (vaci-sankhara) and mental
  choices/intentions/activities (mano-sankhara).
Saṅkhāra Sutta
Comment: good theravadin answer, thanks
Answer: In theravada it is that element which creates that which is created; it creates, therefore it is called the element which creates. As it is thus objectified, it is know as a requisite for other elements so that which forms the formations is classified as formation element forming consciousness as consciousness, formation element forming form as form etc
The classes of past, present & future creating elements are called sankhara aggregate. Sankhara (aggregate) is translated as mental formations or fabrications. Pali discourses explain that fabrications there are intentions, the six classes of intention.
In the Pali texts mind preceeds all created things, it creates them and that which is called mind, consciousness or intellect arises as one thing and ceases as another. Many of the discernable elements are named and known as their coming into play is understood and are named as to their particular function, therefore even tho it is possible to delineate the difference between some elements it would not be possible to take them apart as they are conjoined.

Fabrications
  "And what are fabrications? These three are fabrications: bodily fabrications, verbal fabrications, mental fabrications. These are called fabrications.
"In-&-out breaths are bodily; these are things tied up with the body. That's why in-&-out breaths are bodily fabrications.
  Having first directed one's thoughts and made an evaluation, one then breaks out into speech. That's why directed thought & evaluation are verbal fabrications.
  Perceptions & feelings are mental; these are things tied up with the mind. That's why perceptions & feelings are mental fabrications."
'Whatever fabrications , bhikkhus, has passed, ceased, changed: the term, label, and description 'was' applies to it, not the term 'is' or the term 'will be.'
  "And what are fabrications? These six classes of intention — intention with regard to form, intention with regard to sound, intention with regard to smell, intention with regard to taste, intention with regard to tactile sensation, intention with regard to ideas: these are called fabrications. From the origination of contact comes the origination of fabrications. From the cessation of contact comes the cessation of fabrications. And just this noble eightfold path is the path of practice leading to the cessation of fabrications... The fact that pleasure & happiness arises in dependence on fabrications: that is the allure of fabrications. The fact that fabrications are inconstant, stressful, subject to change: that is the drawback of fabrications. The subduing of desire & passion for fabrications, the abandoning of desire & passion for fabrications: that is the escape from fabrications...
"And why, bhikkhus, do you call them fabrications? 'They fabricate the conditioned,' bhikkhus, therefore they are called fabrications.
  Mind precedes fabricated things; Mind directs them, they are mind-made.
  And what is the conditioned that they fabrications?
They fabricate conditioned form as form;
  they fabricate conditioned feeling as feeling;
  they fabricate conditioned perception as perception;
  they fabricate conditioned fabrications as fabrications;
  they fabricate conditioned consciousness as consciousness.
'They fabricate the conditioned,' bhikkhus, therefore they are called fabrications.
Conditioned Element
  There are, Ānanda, these two elements: the conditioned element and the unconditioned element.
  Bhikkhus, there are these three characteristics that define the conditioned. What three? An arising is seen, a vanishing is seen, and its alteration while it persists is seen. These are the three characteristics that define the conditioned.
  The born, come-to-be, produced,
  The made, the conditioned, the transient,
  Conjoined with decay and death,
  A nest of disease, perishable,
  Sprung from nutriment and craving's cord —
  That is not fit to take delight in.

Excerpts from sutta and abhidhamma


Why Eulerian path can be implemented in linear time, but not Hamiltonian path?

Question: I learned that even though seemingly similar, Eulerian path can be solved in linear time while Hamiltonian path problem is NP-complete. I wonder what is the reason that underlies this difference? I don't know too much graph theory so probably won't understand well a rigorous proof, but some jargons should be fine.
Answer: Basically, the Euler problem can be solved with dynamic programming, and the Hamilton problem can't.
This means that if you have a subset of your graph and find a valid circular path through it, you can combined this partial solution with other partial solutions and find a globally valid path. That isn't so for the optimal path: even after you have found the optimal path through a small part of a graph, this may very well not be a part of the globally optimal path (and in fact, it usually isn't). Informally, the optimal path through a large graph depends on the exact values in all other parts of the graph, and therefore no one has ever found a way to use "divide and conquer" correctly on the problem.
Comment: I think I'm much clear about it now. But did you mean that Euler path is a global valid path while Hamilton path is the optimal path?
Comment: in fact, there seems to be a dynamic programming implementation of graphs, see my answer..
Answer: If we take the case of an undirected graph, a Eulerian path exists if the graph is connected and has only two vertices of odd degree (start and end vertices). This path visits every edge exactly once. So, the existence of Eulerian path is dependent on the vertex degrees and not on the actual number of vertices.
For Hamiltonian path, no simple necessary conditions are known (and of course no polynomial time algorithm). Since the path has to hit every vertex exactly once, the "hard" way is to check all permutations of vertices and see if the path exists.
Comment: Thanks! But why is the necessary condition exits for Euler path but not known for Hamilton path?
Answer: In fact,
the limitation of Hamiltonian path is you have to visit an edge only once. But with Eulerian you might visit the same vertex, and sometimes same edge with opposite direction. In most cases however, it is possible to create a new vertex but merely possible add an edge.
Bellman, R. (1962), "Dynamic programming treatment of the travelling salesman problem", Journal of the ACM 9: 61–63, doi:10.1145/321105.321111 .
If you just check that article, there is a dynamic programming implementation of graphs (not for all kinds of graphs of course).. And also there are some HMM implementations as well,
Björklund, Andreas (2010), "Determinant sums for undirected Hamiltonicity", Proc. 51st IEEE Symposium on Foundations of Computer Science (FOCS '10), pp. 173–182, arXiv:1008.0541 , doi:10.1109/FOCS.2010.24.
The good part of eulerian path is; you can get subgraphs (branch and bound alike), and then get the total cycle-graph. Truth to be said, eulerian mostly is for local solutions..
Hope that helps..


Hadoop Counters documentation?

Question: After my MapReduce job finishes, I get a whole lot of Counter information:
File System Counters
                FILE: Number of bytes read=4386096368
                FILE: Number of bytes written=8805370803
                FILE: Number of read operations=0
                FILE: Number of large read operations=0
                FILE: Number of write operations=0
                HDFS: Number of bytes read=54583718086
                HDFS: Number of bytes written=4382090874
                HDFS: Number of read operations=1479
                HDFS: Number of large read operations=0
                HDFS: Number of write operations=2
        Job Counters
                Launched map tasks=369
                Launched reduce tasks=1
                Data-local map tasks=369
                Total time spent by all maps in occupied slots (ms)=34288552
                Total time spent by all reduces in occupied slots (ms)=232084
                Total time spent by all map tasks (ms)=8572138
                Total time spent by all reduce tasks (ms)=58021
                Total vcore-seconds taken by all map tasks=8572138
                Total vcore-seconds taken by all reduce tasks=58021
                Total megabyte-seconds taken by all map tasks=35111477248
                Total megabyte-seconds taken by all reduce tasks=237654016
        Map-Reduce Framework
                Map input records=14753874
                Map output records=666776
                Map output bytes=4383426830
                Map output materialized bytes=4386098552
                Input split bytes=47970
                Combine input records=0
                Combine output records=0
                Reduce input groups=1
                Reduce shuffle bytes=4386098552
                Reduce input records=666776
                Reduce output records=666776
                Spilled Records=1333552
                Shuffled Maps =369
                Failed Shuffles=0
                Merged Map outputs=369
                GC time elapsed (ms)=1121584
                CPU time spent (ms)=23707900
                Physical memory (bytes) snapshot=152915259392
                Virtual memory (bytes) snapshot=2370755190784
                Total committed heap usage (bytes)=126644912128
        Shuffle Errors
                BAD_ID=0
                CONNECTION=0
                IO_ERROR=0
                WRONG_LENGTH=0
                WRONG_MAP=0
                WRONG_REDUCE=0
        File Input Format Counters
                Bytes Read=49449743227
        File Output Format Counters
                Bytes Written=4382090874

Where can I find an explanation for what each of these fields mean? Some of them are fairly obvious  (Number of bytes read), but others are more ambiguous (Total time spent by all maps in occupied slots vs Total time spent by all map tasks).
I found a list of all the default counters, but I can't seem to find an explanation or description of them.
I'm fairly surprised that I can't seem to easily find documentation about this output. Can anyone provide a link or an explanation?
Comment: See this link for some info on this: http://stackoverflow.com/questions/25482426/explanation-for-hadoop-mapreduce-console-output
Comment: The explanation for these counters are available in Chapter 8 (Map Reduce Features) of the Book
Hadoop - The Definitive Guide 3rd Edition by Tom White Hope this helps.
Raj
Answer: Chapter 8 of the Hadoop: The Definitive Guide (full PDF in link from Washington State University), provides details of Counters, to do with MapReduce. This starts on page 225 and are listed in Table 8-1. A more up to date edition (4th) of this resource is available at Safari Books Online (you will need to log in first).

Hadoop Counters documentation?


Why is there a breakdown in Kolmogorov scaling in turbulence?

Question: Why is there a breakdown of Kolmogorov scaling in turbulence? What causes intermittency?
Answer: The basic Kolomogorov theory is a mean-field theory -- dissipation rate is considered to be constant over the whole volume of liquid.  While the dissipation rate should depend on position -- that is where intermittency comes from.
Somewhere in 60's Kolmogorov and Obukhov attempted to account for this effect. But the problem is that there is the "Landau objection" -- the impossibility to devise universal formula, independent on the geometry of the problem (with scale $l$) for relatively small scales (which are $ \ll l$):

... It may be thought that the possibility exists in principle of obtaining a universal formula, applicable to any turbulent flow, which should give $B_{rr}$ and $B_{tt}$  for all distances $r$ that are small compared with $l$. In fact, however, there can be no such formula, as we see from the following argument. The instantaneous value of $(v_{2i}-v_{1i})(v_{2k}-v_{1k})$ might in principle be expressed as a universal function of the energy dissipation $\epsilon$ at the instant considered. When we average these expressions, however, an important part will be played by the manner of variation of $\epsilon$ over times of the order of the periods of large eddies (with size $\sim l$)  and this variation is different for different flows. The result of averaging therefore cannot be universal.

(Fluid Mechanics, Landau and Lifshitz, chapter 34.)
Comment: Great question and a great answer @Kostya +1
Answer: Another way of seeing this has recently come out of the Functional Renormalisation Group (FRG) method.
Usually Renormalisation Group (RG) flow equations are local in momentum. This means that the correlation functions of two theories that are coarse grained at two neighbouring (momentum) scales $k$ and $k+dk$ only differ for momenta close to $k$. It was found here that this decoupling property (momenta that are not close to $k$ decouple from the rest of the RG flow) is not satisfied for the problem of turbulence. This property was associated with the presence of a cascade of energy here.
Then there is indeed no chance for universality to occur since large scale properties affect the RG flow of correlation functions at all momentum scales. Moreover, this makes it possible to consider multi-scaling within the RG framework since the RG flow can never truly reach an Infra-Red fixed point.


easiest tool to use for a extreme beginner for classification/clustering

Question: I saw that the tool weka is having a gui interface. This gui interface is very easy for non coding users to classify data sets into classes. Matlab is very difficult since say for example making a neural network you need to write code and to do that you need to have a solid understanding of whats going on. Are there other tools like weka or else is there a plugin to matlab that gives more power to it?
Answer: RapidMiner has a functional GUI, and will work for both classification and clustering. It is the most popular open-source (free) data mining application available as of 2012.
RapidMiner: http://rapid-i.com/
It also has numerous training videos and tutorials that you can follow along with - I learned basic clustering methods using a K-means cluster method in about 3 hours. See the Vancouver Data blog for some great RapidMiner analytics videos. Top-notch stuff, really.
Vancouver Data (Neil McGuigan): http://vancouverdata.blogspot.com/
As a bonus, you can install the Weka plug-in, which then gives you GUI Weka. All of the add-ons are free and well-integrated. Other add-ons include a GUI 'R' (the stats program), Reporting Services, Text and Web Analytics, etc. It is fairly simple to use straight 'out of the box' (IMO).
Comment: is a Hidden Markov Model also implemented?
Comment: HMM plugins for RapidMiner are available here: http://hector.cs.ucf.edu/teamwork/?page_id=86 and here: http://code.google.com/p/rapidminerhmm/. I haven't evaluated these plugins, as a FYI.
Answer: Weka is very (very) powerful and you can write your own classifier if that's what you need to do.
Between Matlab and Weka there's pretty much nothing you can't do in terms of Machine Learning.
You might want to check out Netlab toolkit for Matlab, which is a neural network toolkit developed by a Professor at Aston University - it is available from http://www1.aston.ac.uk/eas/research/groups/ncrg/resources/netlab/


What is the definition of ideal boundary?

Question: In many papers about dynamical system,  I found the word " ideal boundary". T don't know what is the definition of ideal boundary.
Answer: For a Hadamard space $X$ there are two kinds of ideal boundaries, the set $Bd(X)$ of horofunctions up to additive constants, and the set $X(\infty)$ of equivalence classes of rays. These two are homeomorphic by the correspondence:

$$\gamma \text{ (a ray)}\to \text{the Busemann function of } \gamma$$
  $$h \text{ (a horofunction)}\to \text{the gradient of } h$$

Here you can find lecture notes by Ballman, with chapter two treating the boundary at infinity via Buseman functions and via rays. You will also find definitions in this paper and this paper.
Comment: You could also look at Bridson & Haefliger's book *Metric spaces of non-positive curvature*.
Answer: There are infinitely (uncountably:-) many definitions of the ideal boundary.
So you have to specify which paper you are reading:-)
See, for example M. Brelot, On topologies and boundaries in potential theory
and Constantinescu, Cornea, Ideale Ränder Riemannscher Flächen.
The simplest example of an ideal boundary is one point compification.
But depending on context, one usually has a space of functions, and one wants
to add ideal bundary points so that the functions of your space have limits.
(Examples: Prime ends, Martin boundary, etc.)


Using poisson regression model to model change in prevalence

Question: I am working with 3 waves of survey data. Many people have been surveyed multiple times, but many others are present only in 1 or 2 waves due to drop-off/resampling. Therefore, my design is multiple cross-sectional taking into account clusters of respondents across time.
My outcome is access to a specific service over the previous year (count variable, not very skewed, it goes from 0 to 16). I have a set of covariates (age, sex, income, education, etc), my main variable of interest is 'year of survery'.
Using the survey weigts I computer the standardized prevalence over the three survey years. However, i want to model the prevalence variation over time (controlling for covariates), therefore, I fitted a Poisson panel regression model using the cout outcome as dependent variable, time - as continuous variable - as main variable of interest and controlling for covariates. I accounted for clustering when computing the SE.
The IRR for time is 0.94 0.93-0.95
I have couple of questions:

what does the IRR mean in this context? In my case I am modelling change of a count variable, without setting offset/expected ratio as option (i am not using rates). Respondents might drop off, others recruited later. To me it seems that I am modeling the change in prevalence ratio, do you agree?
is it correct in this case to use survey year as continuous variable? I believe that the IRR in this case gives me the slope (the yearly change - considering the the survey is taken every year). I wouldnt consider to use survey year as categorical but just double checking.
shall i apply the survey weights (cross-sectional) when running the Poisson regression model? Results are almost identical but I just want to be accurate. I know there is no consensus but I would like to hear more

Thanks
Answer: Another option might be to model the change in prevalence rates using a binary outcome (i.e. at least two access per year). However, I thought that using a count outcome would have been more informative


Crawl space water

Question: We have had 3 straight days of rain and I noticed a small amount of water seeping under scrawl space wall. My space has a vapor barrier and is in decent shape. I did notice the finder blocks on frame of space are dark/damp on each side. Assume it is water making its way down through ground. Any suggestions to help? I will tackle ways to drain better around the foundation and away from my house. Is this normal for water in crawl space?
Comment: What has worked out well for me was to pipe every last drop of water from my gutters on the high side of my house, which happens to be the front, to the back yard.  In ridged pvc drain pipe. Even with the non stop rain we've had my basement is dry, which hasn't always been the case. Proper grading along the house and gutter management has gone a long way for me.
Comment: Is surface water collecting on the side of the foundation where the water is coming in or is this water coming up from a raised water table?
Comment: It is wet and soggy along where I think it is but not puddles. Probably from raised water table under ground. I am in Georgia so lots of clay opposed to soil. Also my home is on a hill and everything flows one way. The crawl space and where it's wet is on the high end of the house. It is most flat in terms of the ground where I feel water is collecting.
Answer: When there is uphill ground leading down to a house the standard intervention is to locate an underground drain (a so called "French drain") to intercept the ground water and surface water and conduct it around the foundation and downhill away from the foundation.
In some cases the trench for this drain (3 ft or 4 ft deep and filled with gravel or crushed rock over a perforated pipe) is located close to the house (within 3 ft) and in others it is placed farther away.
Comment: I know many homes have water in there crawl space after a real but with your scenario Jim's answer would prevent water from collecting.+

Crawl space water


Wrong starting folder in Gnome programs under KDE

Question: I originally installed ubuntu but switched to using kde. Now every gnome programs (e.g. gnome-terminal or gedit) start with ~/Downloads as standard folder. gedit always wants to save in ~/Downloads and gnome-terminal puts me in ~/Downloads. Konsole doesn't. What do I have to change to set this right?
Answer: for some reason KDE uses the "DocumentPath" for all these, changing it to ~ does the trick, but is there a nicer way still?


What happened to icloud.com/activationlock page?

Question: I'm working in a pawnshop and when people attempt to sell or pawn an iDevice, I used to check its serial number or IMEI in icloud.com/activationlock. Now, without that tool, I'm concerned about activated phones that bypassed the activation lock with third party solutions.
Once a co-worked bought an iPhone 5 with iOS 7 apparently without iCloud account, when she tried to reset the phone, the activation lock asked for the owner's Apple ID, then I found the Apple's official tool to check phones IMEI and since, it has been very useful.
First, I want to know why Apple got rid of that page? And there is another alternative to check the activation lock status of an iDevice?
Answer: Apple removed it.  It was being used as part of a hack (a very detailed hack) to allow people to get around Activation Lock.


What kind of spider is this? And is it dangerous? (photo)

Question: I found this spider hanging from a web off the side of my house (in Buffalo, NY). It's probably 3-4in total length. Any thoughts on what kind of spider this is? And if it's dangerous?
Answer: I would think this is a European garden spider (or cross spider). See here and here.
It can bite humans but it is not dangerous for them.
Comment: Indeed, I recognise it from my European garden. It's not dangerous.
Comment: i think its a cross spider because it doesnt have hair around its legs
Answer: Looks like a variety of the very common and diverse group of "garden" and/or "orb weaver" group(s).  They really pop up everywhere during the spring/summer but die off w cold weather (in southeastern US).  Like mentioned, they'll bite but not poisonous...  They're the guys whose webs you're constantly being freaked out by when u hit it face-first---but then never see the spider, or at least aren't bitten normally.
The ones you gotta watch for around here don't make webs that you'll typically see, and either leave their webs often and/or remain in cracks/crevices (e.g.) brown recluse or black widow...).
Comment: If you're in NY- I'm pretty sure you would need be worried only about brown recluse and black widow- if even applicable up there (I'm in GA, so warmer here...).


Android page Curl animation

Question:
Is there a simple way to do the Curl page flipping animation? A Curl animation is animation of pages flipping, including the page above rolling and the shadows over the lower page.
What is the recommended way to do a "gallery" that displays two pages at a time (just like a book)?
Is it:

Letting the adapter display a linear layout of two images at a time? (it won't let me show a page flipping over the other like a book)
Using two pages, placing somehow one near the other, and then when it's time to animate -move the next two pages over?
What is the better way that would enable displaying the left page flipping over the right page?
Comment: possible duplicate of [Implement page curl on android?](http://stackoverflow.com/questions/3912849/implement-page-curl-on-android)
Answer: I'm implementing a 2D page curl in the native canvas. Check my answer in: Implement page curl on android?
EDIT: The code project of my implementation: http://code.google.com/p/android-page-curl/
EDIT2: Links updated
Comment: You know what? I take it back. Well, it's still not the Curl as Apple presents it but it's very impressive and yeah, when the price for Apple like curl is compatibility and lots of time, I'd rather change the requirements to use your code.
Comment: First, thanks for the links to a 3đ attempt. Switcher is nice but it does not implement what they did in Apple. You should see it in iBooks to understand.
Comment: @Meymann it's not a flipper (named the project a bit badly...) it's a page curl effect. The project logo is just a screen shot from the app itself. Try it out.
Comment: Nice to hear it :D I hope that soon the curl will have it's adapter so that it will use any existing Android view.
Comment: Yup, I suppose it should be satisfactory for now. If I wait for an Apple Curl, I should wait long. Apple did put plenty of money on it so I bet it's patented or so. I don't believe that in Android people will do it soon. After all, transparency and reflection is so much work for so little wow effect. I guess that those who wish to do real 3D effect will use something like Unity 3D.
Answer: I am using this code. Its really really perfect for any one to understand and use. Thanks a lot to Harism
GitHub Link for Page Curl Animation in android With OpenGL
Comment: Hey hi , I am also using the code by harism but got into a issue when try to go back to the previous pages the index doesn't stay correct and bitmaps doesn't get refreshed at the right indexes. http://stackoverflow.com/q/16772734/1503130 , this is a thread I have created, Please help with a suggestion or idea.
Answer: I haven't worked on the android before, but it seems to me the best way to do a page flipping type of display would be to draw it in three layers.  The first being the first page's text, the second being the "page" underneath, and the third being the next page.  If you draw them from back to front, the only thing the user will see will be the text on the first page.
Now, Once you have that, you'll want to do some sort of curling/flipping animation based on whatever controls you are using.  Simply choose whatever method works best for you for doing that animation, but while you are doing that, have the part of the page that isn't there anymore alpha'd out.  This will allow you to see the text of the page underneath (Okay, I lied.  You'll need a background behind that text too).
The problem at this point is you're still drawing the text twice over the same space, so you'll want to blend the first page's text with the animation under it.  In this way, the text that is over the 0 alpha sections will be invisible.  It won't bend with the animation, so that may still be an issue, but depending on the speed of the flip that might be fine still.  When the animation is done, simply set the first page = the second, the animation reset to plain white, and the second page = the new second page.
The shadow effect can be done simply by partially alphaing out some black behind the page turn animation.  Draw over second page (as the animation layer already is doing) and voila!
I believe your two page question could use a very similar method.  Good luck
Comment: Thanks but I guess there are a few things that you might have not understood about Android and the problem: A. The CURL means rolling of a page. Shifting pages one on top of another requires 2 pages in Android and one simple animation. The CURL involves a mathematical model with twisting, 3D and shading.
B. In Android, you should interpolate the animations, each in a different path and acceleration, in a way that the shadow and the pages are synchronised. This is almost impossible. Even if you succeed, the performance would be awkward.

Thanks
   M.
Comment: Meymann: I think you just contradicted your question and called the task of doing a page curl impossible. Lunin is right, though, the best way to accomplish a page curl is to do a strictly 2D animation (which can be done fairly easily on most Android device processors) on a canvas control. This can be animated using a timer. It could be done with OpenGL, sure, but nearly half of Android devices are running either without hardware acceleration or on sub-par GPUs. 3D is a poor choice of implementation. A simply 2D version (with some gradient drop shadows, of course) would fit the bill.
Comment: Again: "Curl" is the act of flipping pages. Flipping with an effect of  shadowing, and having the tip of the page rolled (with transparency, shadowing ***AND 3D***) over the lower page. CURL in iPhone OS is a fruit of a month of research and mathematical models. With Android, you can shift one page over another. Shading means another perfectly synchronized layer (another problem), and there is no way of 3D rolling a view with just 2D graphics.
Comment: scuse the necro - is there any way of doing a grab of each page and working with the images rather than the actual pages?
Answer: This is 3d animation project (based on OpenGL 2.0) - http://anettosoftware.co.uk/npc.php

Android page Curl animation


Should I integrate the notations of different papers in the prior works section of my thesis?

Question: I am writing the "Prior Works" section of my M.Sc. thesis. In different papers I saw that there are  different notations for fairly similar concepts. Should I describe each prior work with its original notation which helps people to refer to the original works without confusion or is it better to unify the notation across all of the prior works to make the thesis easier to read.
Comment: There's no universal right answer, but I usually err on the side of making my paper more readable. When the notation change from the prior work is drastic, it's fine to make a parenthetical comment that U is referred to as f in the other paper (for example).
Answer: In my PhD thesis I had a largeish section in the "state of the art" chapter discussing the wildly different conventions, definitions, and notation of previous work in the area, and setting up a common language for comparing them (and later for the main work).
In the resulting papers I just defined the terms, and paraphrased earlier work in them as required.
So, it really depends. In your thesis you do have the space available to make it absolutely clear, in papers/conferences space is at a premium.


slick way of transforming an integral?

Question: The function
$$
(\alpha,\beta) \mapsto \int_0^\beta \frac{\sin\alpha\,d\zeta}{1+\cos\alpha\cos\zeta}
$$
is a symmetric function of $\alpha$ and $\beta$.  But I don't know a simpler way to see that than by actually finding the integral.  Do the Weierstrass tangent half-angle substitution and keep turning the crank until you're there.  Suppose you don't want to know the integral but only want to show symmetry in $\alpha$ and $\beta$.  Is there some clever way to transform the integral into one in which $\alpha$ and $\beta$ play self-evidently symmetrical roles?
Comment: It has been pointed out in this forum by Fred Rickey that Weiestrass had nothing to do with that subsitution that Stewart's calculus text names after him, so I've replaced that name.
Answer: First note that $$\dfrac{\sin(a)}{1+\cos(a) \cos(y)} = \left. \dfrac{\sin(x)}{1+ \cos(x) \cos(y)} \right \vert_{x=0}^{x=a}$$
Hence, let us try to write $\dfrac{\sin(a)}{1+\cos(a) \cos(y)}$ as an integral in $x$ from $0$ to $a$. We get that $$\dfrac{d}{dx} \left( \dfrac{\sin(x)}{1+ \cos(x) \cos(y)}\right) = \dfrac{\cos(x) + \cos(y)}{(1+\cos(x) \cos(y))^2}$$
Hence, we have that $$\dfrac{\sin(a)}{1+\cos(a) \cos(y)} = \int_{x=0}^{x=a}\dfrac{\cos(x) + \cos(y)}{(1+\cos(x) \cos(y))^2}dx$$
Hence, we have that
$$I(a,b) = \int_{y=0}^{y=b} \left(\int_{x=0}^{x=a}\dfrac{\cos(x) + \cos(y)}{(1+\cos(x) \cos(y))^2}dx \right) dy$$which is symmetric about $a$ and $b$. Hence, $$I(a,b) = I(b,a)$$
Comment: I'm already wondering if this is a special case of something involving a fraction whose numerator is $e_1+e_3+e_5+\cdots$ where $e_k$ is the $k$th-degree elementary symmetric function in $\cos(x_1),\cos(x_2),\cos(x_3),\ldots$, and whose denominator is the square of $e_0+e_2+e_4+\cdots$.${}\qquad{}$
Answer: I guess one way would be to go half-way though the Wierstrass substitution. Let $ \tan \frac{\zeta}{2} = t \tan \frac{\beta}{2}$, making it:
$$\begin{eqnarray}
   \int_0^\beta \frac{\sin \alpha}{1+\cos \alpha \cos \zeta} \mathrm{d}\zeta &=& \int_0^1 \frac{2 \tan \frac{\alpha}{2} }{\left(1+\tan^2 \frac{\alpha}{2}\right) + \left(1-\tan^2 \frac{\alpha}{2}\right) \frac{1- t^2 \tan^2 \frac{\beta}{2}}{1+ t^2 \tan^2 \frac{\beta}{2}} } \frac{2 \tan \frac{\beta}{2}}{1+ t^2 \tan^2 \frac{\beta}{2}} \mathrm{d}t \\
&=& \int_0^1 \frac{4 \tan \frac{\alpha}{2} \cdot \tan \frac{\beta}{2}}{ \left(1 + \tan^2 \frac{\alpha}{2}\right)\left(1 + t^2 \tan^2 \frac{\beta}{2} \right) + \left(1 - \tan^2 \frac{\alpha}{2}\right)\left(1 - t^2 \tan^2 \frac{\beta}{2} \right)} \mathrm{d}t \\
 &=& \int_0^1 \frac{2 \tan \frac{\alpha}{2} \cdot \tan \frac{\beta}{2}}{ 1 + t^2 \tan^2 \frac{\alpha}{2} \cdot \tan^2 \frac{\beta}{2} } \mathrm{d}t
\end{eqnarray}
$$
which is explicitly symmetric. However the closed form is now readily read off as a table integral:
$$
   \int_0^\beta \frac{\sin \alpha}{1+\cos \alpha \cos \zeta} \mathrm{d}\zeta = 2 \operatorname{arctan} \left( \tan \frac{\alpha}{2} \cdot \tan \frac{\beta}{2} \right)
$$

Alternatively one could proceed with the differentiation. Let $F(\alpha,\beta)$ denote the original integral. Then
$$
   \frac{\partial F(\alpha,\beta)}{\partial \alpha} = \int_0^\beta \frac{\cos \alpha + \cos \zeta}{\left(1+\cos \alpha \cos \zeta\right)^2} \mathrm{d}\zeta = \left. \frac{\sin \zeta}{1+ \cos \alpha \cos \zeta} \right|_{\zeta=0}^{\zeta=\beta} = \frac{\sin \beta}{1 +\cos \alpha \cos \beta} = \frac{\partial F(\alpha,\beta)}{\partial \beta}
$$
This implies that $F(\alpha,\beta) - F\left(\beta,\alpha\right) = \mathrm{const.}$. The constant must be zero, since the constant is independent of $\alpha$ and $\beta$, and must equal to the negative of itself by interchangeing $\alpha$ and $\beta$ in the left-hand-side.
Comment: or you could set $\beta = 0$ to get that $F(\alpha, 0) = F(0,\alpha) = 0 -0 = 0$.

slick way of transforming an integral?


Does resizing a photo larger or smaller destroy the image quality more?

Question: There are various interpolation settings that image editors use to rescale photos larger or smaller. For some reason, resizing a small photo larger sounds more artificial and destructive than doing the reverse: shrinking it. Is this the correct intuition and why?
Comment: What is the point of this question? What problem are you trying to solve? Nobody chooses to upscale or downscale based on which one is least "destructive". People upscale for some reasons and downscale for different reasons.
Comment: well if fitting the dimension to some size is the aim, only the aspect ratio should really matter. But for whatever reason, it would be good to know whether resizing the aspect ratio based on pixel dimensions would deteriorate image quality or not.
Comment: So you're saying you want to change the aspect ratio of an image? I would do that only through cropping, not by resizing, which would distort the image.
Comment: technically it depends on the image, a black square can be losslessly reduced down to a very few number of pixels while a circle cannot be reduced at all without losing information...
Answer: I would argue the opposite:
Enlarging a picture does not add any new information, but neither is anything discarded. If you view an enlarged picture from an equally increased distance, it should appear pretty much the same as the original. If you shrink it to its original size, you'll get the original picture (ideally, supposing compatible algorithms).
In contrast, shinking a picture does throw information away, and no matter how close you get, you will have lost detail. Enlarging this image will never result in the original again.
Comment: If you start with an image 1000px square, then enlarge it to 2000px, you still have in effect 1000sq px of information, just spread out into 2000 sq px. If you instead halve it to 500px, you've thrown away 3/4 of the information [halve both dimensions, you quarter the number of px], which you cannot ever get back.
Comment: last sentence there seems contradictory that shrinking and enlarging are both destructive ("lost detail" by shrinking)
Comment: So shrinking an image is destructive and enlarging it is not?
Comment: yes. that's the gist of my answer.
Answer: It is true that shrinking an image throws away information that you will never get back.  But the story is more complicated than that.
When you shrink an image, you make any anomalies in it smaller and harder to notice.  You also reduce noise.  Many times I've taken an image that I thought was hopelessly blurred and made it acceptable by shrinking.  Here's one example:

On the other hand, enlarging will blow up those anomalies and make visible what might have been missed.
Comment: What are technical examples of anomalies
Comment: @user610620 I gave you one example, blur.  Another common one is CA.  It's basically a catch-all term for anything that's different from the scene you were taking the picture of.
Answer: This is somewhat true. The information in a digital picture is more or less carried by the pixels, the more pixels, the more information.
When you scale up an image, you create more pixels but don't add any information, so the same information is spread over more pixels and the image is blurry.
When you scale down, you are in the opposite situation, you have to discard information, which is done by operations akin to averaging pixels. The perceived quality of the result is however variable, and depends on the scaling factor: we don't look at a tiny image exactly the same way as a big one, and you can have artifacts caused by aliasing.
Comment: @user610620 you see the blurriness only because you look at it from too close. every picture has its optimal viewing distance. think of a billboard up close.
Comment: One could consider it as not destructive at all. However, if you then try to scale back to the original size, you will get [a different picture](https://imgur.com/vYYTJjO).
Comment: So in general is creating more pixels without adding any information less destructive than scaling down by discarding information? Think the eyes perceive bluriness/pixelation to be a hallmark of poor image quality


Running Linux on VirtualBox

Question: I want to run Ubuntu 16.04 on VirtualBox (and still keep my Windows OS) and I have been given two choices when I start Linux in Virtual Box Try or Install (as superuser).  I don't know which option to choose, I don't want to harm Windows 10.
Answer: VirtualBox creates virtual machines; think of them like computers that run on software (not very accurate but you don't need the details now). These virtual machines are completely isolated from your host operating system (Windows in your case), thus there is no way you can harm your Windows installation.
To your question, "Try" will boot Ubuntu from the iso file you downloaded and you'll be able to get a taste of the operating system, but you'll lose everything you do (in the Ubuntu virtual machine) when you shut down. "Install" will first install Ubuntu in the virtual storage of the virtual machine; thus you'll be able to use it like a normal computer; store files, settings, etc.
Comment: So I should use `install` if I want to use it with Windows 10.  Thanks so much I have been worrying about that for two hours now.  I'm new to this you see and when I saw install I was lost. : )
Comment: Yes, this will make a permanent installation within VirtualBox

Running Linux on VirtualBox


Verification code - when is it asked?

Question: I've read a lot of docs for this and I'm not completely sure of what are the conditions for the login verification code be asked.
Can someone please help with this question and clarify me? Thanks
Answer: There is a really good help topic that outlines the various controls on login access to your org. Paraphrasing from it:

The first thing that is checked on any login is your profile login
hours. If you have login hours on your profile, and you are outside
login hours, the login process stops and you are denied access. No
further checks are done. If you don't have login hours set, or if
you are within login hours, you move to step 2.
Next we look to see if your profile has an IP restriction set on it.
If you do and you are not within the login IP range, you are denied
access. No further checks are done. No verification email. Nothing.
Your access is blocked absolutely. If you are within your profile IP
range, you are granted access.
If there is no profile IP range, then we will look for a browser
cookie set that identifies that this user has accessed this org
previously, or if they are within the organization-wide IP
restrictions (Setup>Security Controls>Network Access). If you are
your browser does not have the cookie, or is you are not within the
org-wide range, your access is blocked...but...there are two ways to
still gain access.

Step 1 is just a gatekeeper step. You won't be granted access solely based on login hours, but you must meet the criteria to get access.
Step 2 is absolute and if a profile IP range is in place completely supersedes step 3.
Step 3 only is tested if there is no profile IP range.
If Step 3 blocks your access, as I mentioned two other options exist to gain access.

The user can click on the Email Me a Verification Code button, in which case it will be emailed to them (SMS is also an option today) and they enter in the code to gain entry. The system will then set a cookie in the browser for the next time they access the org from that endpoint.
The user can pass their security token in with the password.

The first time a new user logs into an org, if there are no IP range restrictions, they will be granted access and the cookie is set.
Comment: Hi @Peter:How can I skip the verification code
Comment: If you login from within the trusted IP range designated in your profile you will never be asked for a verification code. Currently, there is no way to turn this feature off.
Comment: @Peter what about private browsing?  I'm having to type the security code in every time..
Answer: The verification is asked when the user is logging in from a system where there hasn't been a previous login (where there isn't a cookie present), or where the previous login has been expired (cookie expired)
System can be a physical system, but it can also be another client (Chatter Desktop for example), another browser, ...
Answer: Although supposedly cookie-based, why is it that deleting all cookies, or even using private browsing mode in Firefox, does not set off the verification code requirement?  The only thing that causes it to show seems to be several days of not using a given system (or just several days regardless of use or lack thereof).  If it is cookie-based, then how is Salesforce dropping cookies that cannot be deleted or that survive clearing them out?  Smells like they have another way...anyone?
I have seen other sites (namely banks/credit card companies) use a similar system, but that is definitely cookie-based, as private browsing mode fails and/or clearing cookies will require new verification, but not with Salesforce...
Comment: It's not entirely cookie-based (if only partially), but IP-based.  That is, even with private browsing or cleared cookies, if your login is from a "new" IP (and, since we get these on systems that have been used in the past with the same static IPs, then also if that IP has not been used to login in a certain amount of time prior), then you will have to go through verification again, even on a system you may have already used.  That explains why cookie-clearing and private browsing work fine (and Salesforce "remembers" that you don't need to verify in those cases) as well.

Verification code - when is it asked?


Galaxy Stratosphere II Fn button stops working

Question: My Galaxy Stratosphere II's Fn button (on its physical keyboard) has stopped working.  I.E. pressing Fn and then r will normally produce a - (hyphen) character; instead, this combination just produces a r character.  What causes this, how can I make it work again, and how can I prevent it from ceasing to work?
Answer: Realized that I changed the keyboard type from Default to English US.
This is under Home -> Settings -> Language and input -> Physical keyboard -> [the first option].  If something other than sec_keypad: Default is displayed, tap it, click Set keyboard type, and go through the entire list and uncheck anything that is checked.


Can I apply ARIMA(p, d, q) model to testing dataset and make forecast with the testing dataset? Just like the scenario of regression model?

Question: After I fit a sarima model with some historical sales data (for example A dataset), I get coefficients of sma1 and ar1. And I'd like to apply this model to current sales data (for example B dataset) and forecast future sales. That's where my concerns comes up, it seem like neither sarima.for() nor predict() or any other forecasting functions has the 'new.data' argument (I don't mean xreg, so ignore xreg here, I only mean the univariate series itself). Since for general regression models, we can store the coefficient and apply the model to future testing dataset. Does that mean we cannot store the coefficient from the ARIMA model and apply the model to other period of data? If time series works differently, what should I do if I want use the model I get? More specifically, when we say a time series model, do we only mean the p, d, q that we have get, how about the coefficient? Correct me if I'm wrong. Looking forward to any enlightenment!
Answer: For univariate time series forecasting, once you have fit a model and you want to predict new values, the only input to the model is the number of future time steps you want to perform predictions for.
Keep in mind that in a real world business scenario (as opposed to testing the accuracy of the model) the future hasn't happened yet, so there are no inputs available to be fed to the model.
For testing purposes, as I mentioned, the prediction function only takes the number of future steps as an argument. The test data set is used then for evaluation purposes, to be compared to the forecasts, not as an input to the model.
For ARIMA and SARIMA models, the output of the model is fed back to the model recursively to generate future forecasts in the following matter:
Suppose that our ARIMA model is a simple AR(1) model. Generate a forecast for one step ahead $\hat{y}_{t+1} = a*y_t$, then use that to generate a forecast for two steps ahead  $\hat{y}_{t+2} = a*\hat{y}_{t+1}$, etc...until you have $\hat{y}_{T}$ for your desired $T$ steps ahead.
If your model is an AR(2) model. Generate a forecast for one step ahead $\hat{y}_{t+1} = a*y_t + b*y_{t-1}$, then use that to generate a forecast for two steps ahead  $\hat{y}_{t+2} = a*\hat{y}_{t+1} + b*y_t$,  $\hat{y}_{t+3} = a*\hat{y}_{t+2} + b*\hat{y}_{t+1} $, etc...until you have $\hat{y}_{T}$ for your desired $T$ steps ahead.
Comment: Hi, Alex, I understand your point. Let's make up some scenario. For example, one scenario is in general regression analysis, let's make it simple, in linear regression, height and weight has some linear relationship and I want to know the relationship and make use of the model. I fit lm(height ~ weight, data = A) and get coefficient of the weight, namely, height = a + b*weight. Then, I have a B dataset that contains weight data, then I can use a + b* weight (from B dataset) to get estimated height for B dataset. The other scenario, in TS analysis..(to be continued)
Comment: The other scenario, in TS analysis, I use sales weekly data from 2010-2014 to get a SARIMA model, and I have coefficient for ar(1) and sma(1), while I cannot directly use these coefficient to the another dataset B with data 4 months before today to get forecasting for the sales of next month from today ~~
Comment: Is that the difference between TS model and general regression model? In general regression, we can train the model and use the model (coefficients) with other dataset to do forecasting, however, in TS, we can train the model, while must stick to the training dataset to use the model (coefficient) when forecasting, and then forecast is from the latest time point in the training dataset and then afterwards~~ correct?
Comment: To be continued with the second scenario, if in a dynamic situation, each time I want to use the sales data 4 month ago from today to predict sales 1 month in the future, I need to re-fit the arima model, re-gain new coefficients and re-specify n.ahead, since I cannot put the 4-month-ago data to the model I gained from 2010-2014. While in linear regression, I can use the already fitted a+b*weight once for all~~, correct? Correct me if my understanding is wrong~~ Many thanks!
Comment: @EmLp your second scenario is correct. You should refit a new model every time with your most recent data and use that a basis for prediction. If you use model parameters fitted to older data, there's a chance that they are no longer a good fit because in the interim your time series structure has changed (for example from an upward trend to a downward trend).
Comment: Yep, we are in the same page now. So if my model has captured seasonality and trend of the year and I thought it is a good fit then maybe I can use it to make more forecasting points, namely, make n.ahead bigger, to cover current period, while in case new trend comes up as time goes on and in case I want to keep accuracy with the dynamic, I need to make the model dynamic and updated it whenever new data added. So is there any automatic method to choose p, q, d in Arima, since in the dynamic situation, each time I need to make judgement based on ACF and PACF to get the p, q and d?
Comment: I'm not a big fan of auto.arima(), and I don't think it performs well in most of the situations based on my knowledge (correct me if I'm wrong)~~~
Comment: @EmLp outside of auto.arima() I don't know of many options. You could play with using the BIC or the AICc instead of the AIC in auto.arima(). You could also try Cross Validation (although be careful with CV as it is tricky when applied to time series).


Task management for team

Question: I'm looking for a web application to manage tasks (not necessary programming-oriented) for a small team. It must be easy to setup and maintain, and I don't look for an SaaS solution. It must offer file upload and mail users in case of a change. There is hundred of solutions available but most are too complex for what we want or are not "stable" (not updated since a long time, not very well programmed). i was wondering if stack overflow's folks have some recommendations...
Answer: Try:
lighthouse - http://lighthouseapp.com/
-or-
gemini - http://www.countersoft.com/home.aspx
Answer: We had a very similar requirement and after much searching we eventually decided on Redmine.
Does all that you require and more.  Setup couldn't be easier if you use one of the Bitnami stacks.  We went down the virtual image route as we had a VMWare server - but installers for existing platforms are also available.
Comment: a bit too much development oriented  for me
Answer: I tried Basecamp some time ago but I don't need a web based solution. But it was pretty good.
http://basecamphq.com/
Answer: Redmine is a great project management, used by many open source projects. It is also quite actively maintained and really stable.
It's worth mentioning that even though Redmine is software oriented, it can easily be used as a project management software. All you have to do is ignore all the parts about repositories and you have a full-fledged project management software.
http://www.redmine.org/

Task management for team


Single word for "hospital woman worker"

Question: I have been looking for a single word for "hospital woman worker". She will not do any medical related work. She will be doing cleaning, newborn care, and she will also support all the work of hospital employees. Can anyone tell me the single word for "hospital woman worker"?
Comment: British English certainly doesn't have sex-differentiated words for this type of thing (*nurse* is effectively unisex, and *matron* is passe, for example). Regardless of gender, such people are likely to be called [**nursing auxiliaries** or **healthcare assistants**](http://www.nhscareers.nhs.uk/explore-by-career/wider-healthcare-team/careers-in-the-wider-healthcare-team/clinical-support-staff/healthcare-assistant/).
Answer: Hospitals, like most work environments, are tending more away from traditional roles that were dependent upon or at least customarily assigned to members of a specific gender, like nursing or maintenance workers. There are very few gender dependent roles in healthcare or in any business any more, so "hospital woman worker" is likely not an accurate descriptor for any hospital role.
Candy striper is a passé description of young, typically teen, volunteers and that terminology is not generally in use any longer.  Most organizations call non-nursing unlicensed workers in clinical settings "nurse technicians," "nurse techs" or just "techs," implying that they require some specific training for their jobs but not formal training that results in licensure.
Comment: Do you say "Candy striper" not relevant word for "Hospital Woman Worker".?. If not please provide exact word for this term.
Comment: I added a link because it provides a job description.
Answer: Candy striper - A hospital volunteer is sometimes nicknamed a candy striper. This name is derived from the red-and-white striped jumpers that female volunteers traditionally wore in the United States, which resembled stick candy.
I know its not a "single word" but when I read your question Candy Striper came immediately to mind.  There are also various levels of nursing, but the term nurse does not indicate gender, and often concerns many medical functions in the hospital.  Candy stripers are not permitted for perform medical functions, as they are volunteers rather than employees of the hospital.
Comment: This is a very regional term and only applicable in the United States of America.
Comment: I have a doubt. Can i have gender as woman for "Candy Striper"?.
Comment: I believe that the term is gender neutral, but the origin is specifically feminine.

Single word for "hospital woman worker"


Academic reference manager that supports freehand annotation

Question: I currently use Mendeley and have been happy with its organisational capabilities. However, I would like to be able to make freehand annotations and drawings on pdfs, which Mendeley does not support. I've downloaded a trial version of Papers, but I am finding its metadata input extremely clunky and error prone compared to Mendeley. I would like to be able to sync between iPad and Mac easily. Can anyone recommend a good reference manager that supports freehand pdf annotation?
Answer: I can recommend Zoterro. I used it when I was at university. I'd highly recommend the website refme, it was my best friend in university.