Internet Explorer / Windows 7 does not want to show HTML file from local network drive

Question: Setup: I have Windows 7 running inside VirtualBox on Mac OS X host. I have a shared drive with some HTML files, that I am mounting as a local drive W: in Windows, from the VirtualBox server \VBOXSVR. I want to look at them with a browser in Windows.
Chrome in Windows 7 opens and shows those HTML files just fine (file:///W:/welcome.html). But Internet Explorer does not, and shows this error instead of the files:

Internet Explorer cannot display the web page
What you can try: [button Diagnose Connection Problems]
More information
This problem can be caused by a variety of issues, including:

Internet connectivity has been lost.
The website is temporarily unavailable.
The Domain Name Server (DNS) is not reachable.
The Domain Name Server (DNS) does not have a listing for the website's domain.
If this is an HTTPS (secure) address, click Tools, click Internet Options, click Advanced, and check to be sure the SSL and TLS protocols are enabled under the security section.

For the internet zone in the status bar, it shows:

Internet | Protected Mode: On

IE settings are a mystery to me, and I could possibly get it to work by tweaking IE settings, but I don't know which ones.
How do I make IE show the same files that Chrome is happy to show? (Chrome showing them means that the files themselves are fine, there is something about the setup that just makes IE be a diva.)
Answer: If you can modify the file, you can try tricking IE with MOTW to put it in the Internet Zone, http://msdn.microsoft.com/en-us/library/ms537628(v=vs.85).aspx.
Basically add this line to the beginning of the HTML file:

You could also try forcing it into Intranet Zone but that depends on whether you have protected mode on or not for that zone.  This would get you Intranet Zone:

Be sure the file is saved with Windows line breaks (CR+LF).  If you have Text Wrangler you can specify windows line breaks when you save the file.
Finally, another way to use MOTW would require using NTFS Alternate Data Streams (https://stackoverflow.com/questions/4496697/what-is-zone-identifier).  Basically, go to the windows command prompt and type
notepad W:\Welcome.html:Zone.Identifier

In the text file put the following:
[ZoneTransfer]
ZoneId=2

For any of these methods you'll need to completely close IE and reopen for MOTW to behave properly.
Answer: I had the same setup and problem:

Windows 7 in Virtualbox on Mac OS X host.
HTML files in shared folder (\vbozsvr\mySharedFolder) open in Chrome but not in IE10

Problem solved by the following settings in IE10
In Internet Options -> Security:
Internet - Security level "Medium", uncheck "Enable Protected Mode"
Local Intranet - Security level "Low", uncheck "Enable Protected Mode"
Trusted sites - Security level "Low", uncheck "Enable Protected Mode". Also, click the "Sites" button, uncheck the "Require server verification" box, and add "file://vboxsvr" to the list of trusted sites.
Comment: wouldnt it simply be better to add yourself as trusted? reducing security should be a no-no.
Comment: Yup, I realize this is not a good solution (Although I only use these settings when I visit sites that I control myself, for web dev testing puroses). Sorry for being noob: could you please clarify what you mean by "add yourself as trusted"? Thanks!
Comment: i meant this: http://superuser.com/a/149076/179299
Answer: That error page is kind of weird, but here's a crack at it:
If you map the drive by IP address (or by a FQDN that isn't your domain), the mapped drive will be identified as untrusted (aka Internet Zone).
If you map it by name (\\VBOXSVR\Sharename), and it's still not being auto-recognized as Intranet, then you can add VBOXSRV to the Intranet site list in IE manually (Internet Options-->Security-->Local Intranet-->Sites).
Hopefully that'll help you out.
Comment: Thanks, this did not work.

The Windows image is set up with a corporate security/firewall software that I cannot configure. I am starting to think that this software is messing with me.
Comment: This may not have worked in this specific instance, but it should work in similar situations.
Answer: Try this: on the IE menu, Tools > Internet Options > Security tab.  Click Local Intranet.  Click the Sites button.  You should see a set of checkboxes.  Make sure Automatically detect and Include all network paths are enabled.
Comment: Didn't help :( did this but still the same.
Comment: Once you've made the change, does IE show the page in question (W:/welcome.html) as being in the Local Intranet zone?  There should be an indicator at the bottom, in the status bar.
Answer: Why don't you try co copy the files on your windows partition (create a folder on your desktop and drag them there)...
Answer: Works for me:

And i've not configured anything strange in Internet Explorer. Just to be sure we're on the same page (so to speak):

reset security settings to medium:

reset advanced settings to default

possibly even reset IE to factory settings:

But your next step is to make sure the welcome.html renders fine off a local drive; and then run Process Monitor to watch Internet Explorer read the file, and make sure there isn't any Access Denied or some such nonsense.
My psychic debugging tells me that you have some anti-virus malware that is deciding to "protect" Internet Explorer from reading files of the network zone.


Deep learning technique to recognize a person's silhouette

Question: I'm reading Nielsen's book on neural networks. In the first chapter you construct a neural net to recognize handwritten digits by training the network on 60,000 samples. I wonder how would you build a neural net to recognize a person by his/her silhouette? Is there some special technique to make it possible?
Answer: For this purpose you have to have a data-set that can be interpreted by the human. I mean an expert should label the data samples without hesitating. Then you can make a typical neural network and train it. In your case you have 10 classes and all 60 thousand images are labeled by an expert. Consequently, you are able to train a network. Your task is supervised and you need labeled data-set.
Comment: Another idea is to take profile images and convert them to silhouettes - no need for an expert in that case.
Comment: @Imran By expert, I meant there should be someone who can figure out the data that may increase the Bayes error. In the feature space there may be similar input patterns that have different labels but so much identical input patterns. In those cases the Bayes error may increase. But it was too detail, so I didn't refer to :)


What should be the primary focus of the criminal justice system?

Question: The main theories of motives for punishment are retribution, incapacitation, rehabilitation, and deterrence. Which should be hierarchically the primary focuses of punishment? and which views have the best arguments in favor of them?
Comment: @zero No offense. I just mentioned it because you asked for a difference and they listed a bunch of differences in the first paragraph i.e. official vs personal, proportional and limited vs unrestricted, wrongdoings legally defined vs emotionally felt, procedural standards vs suffering and sadism. Aso so retribution would be a formalized and restricted version of revenge. Feel free to disagree with that I just didn't know what you knew.
Comment: oh ok that's fine then @haxor789 well personally i just feel that a will to punish is sadism (etc,), without the need to control. which suggests i am against retributive punishment at all hmm worth thinking about if it was at all salient for me
Comment: I agree with you. I have heard it said, and I believe it, that the greatest deterrent of crime is the calculation that one will not get caught. Detection, detection, detection. I have seldom heard this point mentioned. I suppose because people are so fixated on the punishment process and forget that if that is weak, there can be no deterrence.
Comment: The question seems very subjective and depending on the crime.
Comment: i would think, personally ^ speaking, we should not seek retribution when it will not reduce re-occurrence of the crime, perhaps because it is not clear to me what the difference between revenge and retribution exactly is
Comment: @zero https://en.wikipedia.org/wiki/Retributive_justice
Comment: The primary focus should be to stop crime from happening, either before it does (by deterrence) or after (preventing recidivism). Having been mugged and chopped on the head with a sickle, it is salient for me. The urge for punishment and retaliation harms me ("*drinking poison and hoping your enemy gets sick*"), so I just want to know it is not going to recur, for me or anyone else.
Comment: An alternative: https://en.wikipedia.org/wiki/Restorative_justice
Comment: @Michael unfortunately, the folks who run society are human too. This is why I say that maybe AI will just keep us as pets and all our problems will be over. Or, AI could kill us, or we could destroy ourselves and all our problems would be over.
Answer: Incapacitation within reason, rehabilitation and deterrence are all rational responses to offences. But it is clear that none of the usual punishments is particularly effective in achieving their supposed aims. One of the greatest difficulties is that they can only be achieved if the offender recognizes the punishment as appropriate. Most systems do not pay attention to this, and it undermines the effectiveness of the punishment. Prevention is arguably a much more rational and effective policy.
Retribution can be interpreted as paying back. If this means compensation for the victim, it is also appropriate. But it frequently means some symbolic restoring of balance, and this seems to me very dubious, even if the victim derives some sort of comfort or consolation from the process. It is hard to distinguish this from revenge (in a controlled form).
Foucault suggests that the key point of punishment is to display the power of the authority that inflicts the punishment. There is something to be said for this and if it is aimed at deterring further crime, it might be rational. But since it also displays the weakness of the authority in failing to prevent the offence, the justification seems rather weak.
From the fact that you do not include revenge in the justifications of punishment, it would seem that you do not think that it is any justification. I agree with that. Revenge, it seems to me, is a displacement behaviour that expresses the anger and frustration of the authority and/or the victim at the fact that the offence has been committed.
The key problem is that since nothing can put right the fact that the offence has been committed, it is necessary to live with that. Our institutions seem very bad at acknowledging that. Comparatively little effort goes in to trying to deal with it. If that were the aim, more attention would be paid to working out the conditions for forgiveness, which is the only way that the consequences of the offence, for victim, offender and authority to draw a line under it.
Comment: @ScottRowe Again, I agree with you, both about retaliation (though I have no idea how common it is) and about expecting people not to react when they suffer harm. About the latter, all I can say is, prevention, prevention, prevention.
Comment: Regarding your statement "... if the offender recognizes the punishment as appropriate": many violent crimes are responses to previous actions by others. Someone feels they were harmed, and they retaliate. We catch the second mouse, but the first one made off with the cheese. We could subject criminals to 'philosophy' so they see the error they made, but until the earlier offence stops happening... first, crime will go on. Expecting people to not react to offenses in whatever way is possible for them is not reasonable. We need to lock the barn door *before* the horses get away.
Comment: @IndianLawApplicant. I'm sorry. I don't know the answer to your question. Perhaps someone else will. But I take your point.
Answer: The crucial problem with asking for criteria, paradigms and their priority in an ideal criminal justice system is that the problems with a criminal justice system might stretch beyond the boundaries of such a system.
Like you could naively say that the it's purpose is to resolve, prevent and reduce crime.
The problem is that "crime" isn't really an absolute. You could fairly easily solve all crime. Just scrap all the laws et voilà there is no crime. However as you might have guessed that doesn't really solve the problem that you associate with crime, it just refuses to label it as a problem.
But it exemplifies that laws aren't something absolute that transcends human existence and can be without it, but it's just the result of struggles and negotiations to organize a society. And crimes are just ways to assert ones interests that move around agreed upon ways to assert one's interests.
So to "criminalize" something serves 2 major purposes one is to assert the dominance and authority of the "agreed upon ways" of doing something (law making process, monopoly of violence and (serious) conflict resolution process, aso). So it's simply criminal, because it challenges the current power structure. And the other is to preserve the integrity of society itself. Whether that is for it's own sake, because without society there is no universal law or whether it is because society is needed to perform some task and if everyone is fighting each other that task is not getting done.
So most of that has less to do with "right" and "wrong" and more to do with preserving the power relations, the status quo and the overall stability of a society.
So what the criminal justice system's job would be is to defuse the major conflict within society and to assert itself as the only legitimate way of conflict resolution.
So when crime does damage to society, the goal is to stop the damage from being done, organize the repair of that damage, resolve that underlying conflict and prevent that or something similar from happening again.
And the priority of the options that you've mentioned mainly depends on the crime and the urgency of the problem. Like if you have a fragile system where everything is falling apart you might feel the urgency to assert your dominance and to prioritize deterrence.
The problem is that deterrence is a very temporary solution. To take up an aggressive posture works quite well when it comes to intimidating, confusing and deterring them from a conflict because they didn't anticipate the escalation and aren't prepared for it. But those emotions will decrease over time and the preparation for such an event will go up and if you haven't solved the actual problem in the mean time, that approach is likely going to backfire. Also with regards to ever higher sentences. That doesn't really scale well as the human conception of it doesn't really allow to fully comprehend what that means. Like 3 years are more than 1 year, but life is so fast that you have no conception of what 1 year in prison even means and if you deal that out to often you create a new normal where it either loses it's intimidation factor or increases such a panic that people would commit more severe crimes just do up the chance to dodge it. Leading to the opposite of what it was meant to accomplish.
Likewise if the perpetrator is continuing to be a threat than it might take priority to stop them from doing so. At least on the short timescale. However that doesn't really solve the problem. You can't hold up people indefinitely, that creates ethical as well as resource problems and as well as capital punishment might end up being a treatment that exceeds the crime in terms of brutality and as people are usually social animals with their own social networks that might create an outrage of it own. So if you have to release them eventually you should make sure that you have solved the problem by then.
Whether that is a personal problem, a lesson that needs to be learned, a change in the law or whatnot.
And in terms of retribution in the sense of recoupment and reparation. That works for material damages and monetary losses, although even there you might run into a problem if you want to punish a thief who never had the money to begin with and neither has the money to pay the fine. But it completely fails when it comes to violent crimes as you can't revive the dead and even to "restore" the before attack state of a traumatized person might not be as easy as it sounds on paper.
So ideally the justice system would not treat it as criminal but as a problem that is solved between the different parties, but practically it might pose a very urgent problem to the stability of society and they might resort to symbolic action just to appease people and preserve the status quo.
Answer: Here's how I would prioritize the four:

Deterrence: I would like the criminal act to become extinct.
Incapacitation: Until the criminal can be fixed, keep them away from society.
Rehabilitation: No repeat offenses. Fix the criminal.
Retribution: The victims of the criminal should receive some form of compensation.
Comment: I agree. My only concern is that people do the things they do largely because of circumstances. So, for criminal behavior to stop, the conditions that cause it have to change. I don't know if just a few things need to be fixed, or if basically the entire enterprise of being human is irremediable?
Comment: @ScottRowe Of the four, deterrence needs the most work and its also the most difficult to address. The only deterence currently is fear of incarceration for an extended time, fines, or execution. What other options for deterrence are there?
Comment: Mind control? Anyway, what I meant was that we have made criminality a 'thing', but it arises from the circumstances people grew up in, mostly. To banish crime forever is easy: make everyone's life wonderful. Failing that, there will always be problems. You won't be able to deter it hard enough. Prevention works way better than cure.


What is the program in Python that print information about the current block?

Question: What is the program in Python that print information about the current block the world try to mine (I mean Version, Previous Block, Merkle Root, Time, Bits) plus how many zeros we are looking for for the output of the hash!
Comment: Do you have a need to a parser for file blk?
Comment: @vincenzopalazzo I don't understand what do you mean!
Comment: What are you looking for? where do you want to get that information from?
Comment: @vincenzopalazzo I think that I could get them from a library. How do mining programs get these information?
Comment: From the bitcoin RPC Framework
Comment: @vincenzopalazzo And can't I get the same from this framework in Python so I can print information about the block they're mining now?
Comment: I have tried to add an answer to the question
Answer: To take the information of the bitcoin blockchain, you can use the bitcoin core RPC Framework, for use it, you must have all blockchain on your computer

Download Bitcoin core
aligns the bitcoin node
Configure rpc framework
Use the API to take the information, I prefer using this library with python, this is an example for using it

You can use this documentation for study API
also for a response to the last comment, you can use the API for call the Mining commands but is difficult understand your question "I can print information about the block they're mining now" because the mining is a war for the node and each node can have different information
Comment: Is it oblige to do steps 1 and 2 and 3? Couldn't I use the API directly?
Comment: What are the names of functions that I can get information with them?
Answer:
information about the current block the world try to mine

The world is concurrently trying to mine many different blocks which only have the block height and target (bits/difficulty) in common and therefore have a common prior block hash.

(I mean Version, Previous Block, Merkle Root, Time, Bits)

Although previous block and bits are common to all concurrent mining effort globally, version, Merkle root and time are things effectively chosen by individual miners (or pools) and therefore differ from miner to miner.
To get the target and the hash of the top block, you need to interrogate either a node that you run (e.g. Bitcoin core as vincenzopalazzo suggested) or a public node such as a blockchain explorer. Both have APIs but the APIs differ. There may be Python libraries you can use but which libraries you should use, if any, will depend on which source you select.
Bitcoin core's API has functions useful for constructing block templates.

plus how many zeros we are looking for for the output of the hash!

None. Bitcoin does not ever consider the number of leading zeroes. Adam Black's "HashCash" unimplemented proposal used number of binary leading zeroes but Nakamoto's "Bitcoin" did something different though partially inspired by Hashcash.
The test in Bitcoin is a simple numeric comparison of hash <= target where the target is obtained by expanding the bits you mentioned before and recalculating the next value when appropriate (when block height is a multiple of 2016).


Why does modal interchange work? Can any mode be used?

Question: When you're in the key of C major and you use chords from C Dorian, Phyrgian, Lydian, Mixolydian, Aeolian, and Locrian. Why does it sound acceptable to use those chords, and does it work with all chords from those modes and can any mode be used?
Answer: It might be useful to think about your question a different way. Rather than trying to classify chords according to which modes they are in, forget about "modes" and/or "keys" and just consider the root progressions of successive major or minor chords. There are three basic groups, when the root moves up (or down) by the interval of a second, a third, or a fourth.
The root interval of a fourth produces a "dominant-tonic" or "tonic-dominant" harmonic progression.
The root interval of a third means that the two chords share some common tones, since the chords are themselves constructed by stacking intervals of a third.
The root interval of a second doesn't have such a clear cut function, but it can be an effective part of a longer progression. One example is the interval of a second creating a "secondary dominant" of the following chord - for example progression like C - Dmin/Dmaj/Dbmaj - G - C or even C - B - Emin (as in the start of Mendelssohn's "wedding march", in the key of C)
The first chord of each musical phrase can have almost any (or no) connection with the chord at the end of the previous phrase, so long as the following chords move towards re-establishing a connection that the listener can understand.
In the renaissance period, using meantone temperament, composers didn't think so much in terms of "keys" as in terms of "the set of major and minor chords which were in tune in the given temperament". A chord progression (in the nominal "key" of G) like G - F - C - Am - G - Eb - Bb - C - G - D - G (as used by William Byrd, for example) makes good musical sense, whether or not one gets tied up in knots trying to make it fit into any particular "theory" of harmony.
Answer: Modal interchange is typically a way to simplify looking at chords outside of a scale/key. It's not that it's the only way to view the chords and typically that is far from true, but it gives the non-dictation/chromatic a simple context in a parallel scale/mode. There are two main phenomena which allow this to be extremely common, which are common tones in the chords/scales and chromatism.
Even when considering the furthest you can be away from C Major which is C Locrian, you still have 2 notes in common which are C and F. It's not a lot in this specific case, but if playing an F minor chord in C major you would recoginze that you could play a C Locrian (or F Phyrgian) scale over that chord and give your progression a very different flavor while using the common tones to keep you from going too far outside the key/scale you are in. The chord itself F minor is pretty close to an F major chord, just with the third lowered a semitone and that difference while being pretty big adds a lot of flavor which goes into the next topic of chromaticism.
The chromatic opportunities that can be achieved in modal interchange are what most people use modal interchange for, and really helps make progressions more interesting. For example, in one of my favorite progressions I - ♭VI - IV - V, while you can look at it as simply borrowing the ♭VI chord from C minor (Aeolian), the voice leading inside the progression is much more interesting as seen below:
<code>X:1
L:1/4
M:
K:C
V:1 clef=treble
"I"[C E G] "bVI"[_A C _E] "IV"[F A C] "V7"[G B D F]
%
</code>
As for the question does it always "work", the answer is simply no as not even every progression you make with only diatonic chords "don't work". If you keep the two ideas I stated in mind of common tones and it will typically work, however you still need to see and hear what you do and the effect it has on the progressions.
Answer: I wonder whether you mean what you've written. Dom has explained perfectly well, but did you really mean C Ionian, C Dorian, C Phrygian, etc.,all based on 'C', but all actually belonging to completely different keys.
For example, C Ionian has C,D,E,F,G,A and B, whereas C Phrygian has C,Db,Eb,F,G, Ab and Bb, and C Lydian has C,D,E,F#,G,A and B. So, between all the modes of C - all 7, making chords which come from each mode, there is just about every chord known to man available, from all the different notes!
So - if as you say, you're playing in C major, the opportunity to play most of these chords is very slim. Dom has explained how they could fit, but I think you actually meant the chords of C Ionian, D Dorian, E Phrygian, etc., which are the same chords for each - made from the same 7 notes. Since there is now a finite number of chords, each triad containing notes from the parent major key of C, it makes it easy to understand how, when you're playing in the key of C major, that the modes and chords from that parent major will fit.
NOTE: the terminology is confusing. C Dorian contains the notes from Bb major,(centring around C), whereas the Dorian OF C contains the notes from C major (centring around D)
Comment: So techinally all of these modes, are based on altered variations of scales that can be composed using the chromatic scale, some got flat notes and some got sharps. So i can replace any chord with another chord if i wanted to? like a I-vi-VI-V in c major, i could replace the c major with a diminshed and the a minor with an A major and the f major with a f minor and the g major with a g minor, there shouldnt be any rules against it right? IF i want a certain mood i should be able to do it, maybe id have to establish the key first then do it, but it should be plausible at the least. Am i wrong?
Comment: @JaniceCee - Need to get one thing straight! The 'rules' are man-made to help guide us through. They are certainly NOT 'laws'. As such, anyone can do whatever they want, musically. It won't ever be 'wrong'. It may (or may not) sound bad, but it will depend a lot on its context.What you're saying is can you have I-vi-IV-V in , say, C, and play a different chord that is C based, another different for the Am, another instead of F, but still IV rooted, etc.I think. Yes, of course. BUT - the proof's in the pudding. If it sounds good, it usually is, and vice versa. The substitution of different (con
Comment: t) chords , i.e. C min for C maj is something that happens frequently. Often, the reasoning behind it is 'using parallel key' notes/chords, rather than the way you describe, changing the mode, but keeping the root note, although to a degree, it comes down to the same idea. So, in C, C, Dm, Em, F, G, Am Bo are used, and from parallel Cm - Cm, Do, Eb, Fm, Gm, Ab, Bb will be the most used. D maj comes into play from 'it's the dominant of the dominant' but could also be construed to be from C Lydian, if you prefer. Like Emaj, as the dom of Am. Almost anything can be justified in musical terms...
Answer: When looking for a new, interesting harmonic colour in a piece of music, we don't go through a catalogue of 'permitted' modal interchanges.  We MIGHT think 'let's try this chord shape shifted up or down a step'.  Or perhaps 'let's try this chord with one (or more) notes slightly shifted'.   Or even 'what's the GREATEST contrast I can find to the home chord?'  (funny how often an F♯ chords gets thrown into a C major passage, purely for shock value :-) )
Then the sort of theorist who's uncomfortable with anything being 'out of scale'  starts looking for a way to make these chromatic chords not REALLY chromatic, but sort-of extended diatonic. And he can usually find one.
Comment: Ah, you just don't get it. I actually _like_ the sound of F# over C, it's always been very fascinating and only recently I've found ways to handle it with some kind of a framework so I can find related sounds. You can throw all that in the chromatic bin if it doesn't feel worth further contact.
Comment: I quite like it too.  And, having done it once in a piece, it obviously makes sense to do it, or something like it, again.  But is that quite what we're talking about?


Where do I put $this->request->headers('Content-Type', 'application/json');

Question: I'm trying to change the content-type to application/json in Kohana. I put this in an action in my controller:
$this->request->headers('Content-Type', 'application/json');
$this->content = json_encode($json_data);

The request however, has still the text/html content-type.
Where should I put $this->request->headers('Content-Type', 'application/json');   ?
Answer: To elaborate on Claudio's answer, yes you need to set the response header, not the request, like so
$this->response->headers('Content-Type','application/json');

Also, I'm not sure how you've implemented your controller, but it looks like it may be a template controller based on
$this->content = json_encode($json_data);

If you are using a template controller, make sure you set auto_render to FALSE.
Finally, set the response body with your json data
$this->response->body(json_encode($json_data));

Answer: Well, you need to edit the response headers.
http://kohanaframework.org/3.1/guide/api/Response#headers
Answer: The OP asked where to put it. If you're using a controller that extends Controller_Template, like I am, I just added Andrew Schmid's code example to my base controller's after() method (before parent::after()) and it worked great.
So:
Controller_Your_Controller extends Controller_Template {

   // Your controller actions

   public function after()
   {
       // Set the response content-type here
       $this->response->headers('Content-Type','application/json');
       parent::after();
   }
}


Why is it right to use the word "from" to say "there was no place free from them"

Question: I would use the word "of" as the word "from" indicates origin so it sounds a bit weird.
I read this in a periodical from JSTOR talking about immigration to the old border states.
Comment: We say: The garden was full of bugs. No corner of it was free from them. Applied to people, it sounds slightly racist.
Comment: [**from**, Definition 2](https://www.merriam-webster.com/dictionary/from): used as a function word to indicate physical separation or an act or condition of removal, abstention, exclusion, release, subtraction, or differentiation; protection *from* the sun, relief *from* anxiety
Answer: The simple and complete (though possibly unsatisfying) answer is that the adjective "free" in this sense correlates with the preposition "from".
The meaning of "free" in this context from Merriam-Webster is:

4 a : relieved from or lacking something and especially something unpleasant or burdensome

This means if you use "free" in this sense, then "from" is one of the correct prepositions to connect "free" to its object.
There is no grammatical reason beyond that. There are etymological roots to that correlation, but etymology isn't grammar.
Comment: @EllieK-Don'tsupporther I chose not to mention "free of" in my answer because it's tangential to a question about "from", but I was careful to say that "from" is ***one of** the correct prepositions*.
Comment: Sometimes *free of* can be substituted -  *Free from mosquitos* and *Free of mosquitos.*  Am I free *from* mosquitos while my backyard is free *of* mosquitos?  Sometimes it cannot be substituted.  *Free from the drudgery of housework* and *Free of the drudgery of housework*.  Or does that work too?
Answer: Bryan Garner asserts, in his Dictionary of Legal Usage, that both free from and free of are correct but also notes a distinction with the noun form: We speak of freedom from something unpleasant or onerous (freedom from oppression, pestilence, coercion) but use of with something neutral or beneficial (freedom of speech). (Also free of charge.)
I suggest that the distinction should also be maintained with free from [something onerous] and free of [something neutral or beneficial], given that readers have unconsciously stored the distinction noted above.


lxc/kvm containers fail to start

Question: I have MAAS+Juju setup ready and was successfully able to deploy some openstack charms on specific machines. Then, I read that its safe and good practice to place these openstack charms in their own containers. I tried
juju deploy --to lxc:14  --repository=/opt/charms local:trusty/keystone

Charm was added successfully but juju stat shows
  "14":
    agent-state: started
    agent-version: 1.20.10
    dns-name: slot13.maas
    instance-id: /MAAS/api/1.0/nodes/node-9cf5e120-5625-11e4-b22e-a41f72f16283/
    series: trusty
    containers:
      14/kvm/0:
        agent-state-info: 'kvm container creation failed: exit status 1'
        instance-id: pending
        series: trusty
      14/lxc/0:
        agent-state-info: container failed to start
        instance-id: pending
        series: trusty
    hardware: arch=amd64 cpu-cores=4 mem=32768M

I tried with kvm containers with the same result ( you can see even that error above. For KVM containers, I did enable Virtualization tech in BIOS ).
juju debug-log shows
machine-14: 2014-11-05 06:31:12 ERROR juju.container.lxc clonetemplate.go:167 container failed to start: container failed to start
machine-14: 2014-11-05 06:31:12 ERROR juju.provisioner.lxc lxc-broker.go:97 failed to start container: container failed to start
machine-14: 2014-11-05 06:31:12 ERROR juju.provisioner provisioner_task.go:418 cannot start instance for machine "14/lxc/0": container failed to start

There are no service/charm(keystone) specific logs at /var/log/juju on the target node. This is happening with all services that I wish to place in a container, not only keystone or openstack services.
Note: I had a problem with lxc-create on the target node because of some proxy issues and I think that my earlier post on this solved that issue. But the issue I describe in this question doesn't go away.
EDIT: I found the container failure logs and am pasting the same here-
 lxc-start 1415307100.508 INFO     lxc_conf - mount points have been setup
      lxc-start 1415307100.508 WARN     lxc_conf - rootfs specified but no console found at '/usr/lib/x86_64-linux-gnu/lxc/dev/console'
      lxc-start 1415307100.508 ERROR    lxc_conf - No such file or directory - failed to create symlink for kmsg
      lxc-start 1415307100.508 ERROR    lxc_conf - failed to setup kmsg for 'juju-machine-14-lxc-1'
      lxc-start 1415307100.508 INFO     lxc_conf - 0 tty(s) has been setup
      lxc-start 1415307100.508 ERROR    lxc_conf - No such file or directory - Error creating /usr/lib/x86_64-linux-gnu/lxc/dev/fd
      lxc-start 1415307100.508 ERROR    lxc_conf - failed to setup /dev symlinks for 'juju-machine-14-lxc-1'
      lxc-start 1415307100.508 ERROR    lxc_start - failed to setup the container
      lxc-start 1415307100.508 ERROR    lxc_sync - invalid sequence number 1. expected 2
      lxc-start 1415307100.508 WARN     lxc_conf - failed to remove interface '(null)'
      lxc-start 1415307100.540 ERROR    lxc_start - failed to spawn 'juju-machine-14-lxc-1'
      lxc-start 1415307100.540 WARN     lxc_commands - command get_init_pid failed to receive response
      lxc-start 1415307100.540 WARN     lxc_cgmanager - do_cgm_get exited with error
      lxc-start 1415307105.545 ERROR    lxc_start_ui - The container failed to start.
      lxc-start 1415307105.545 ERROR    lxc_start_ui - To get more details, run the container in foreground mode.
      lxc-start 1415307105.545 ERROR    lxc_start_ui - Additional information can be obtained by setting the --logfile and --logpriority options.

The first error rootfs specified but no console found at '/usr/lib/x86_64-linux-gnu/lxc/dev/console' is indeed right in the sense that there is no path '/usr/lib/x86_64-linux-gnu/lxc/dev/console'. The dir structure ends at '/usr/lib/x86_64-linux-gnu/lxc/`
Comment: Ugh... those logs are impossible to decrypt. "container failed to start: container failed to start" why tell me the same *twice*? I would report a bug asking that the logs provide less redundant/more relevant information to solve this issue.
Answer: I had a similar error. Not exactly the same, but the solution was to remove the lxcs.
rm -rf /var/lib/lxc/offending-container-xx
rm -rf /var/lib/juju/containers/offending-container-xx

If someone comes across a similar error, hopefully this will help.

lxc/kvm containers fail to start


Is mining still profitable in october 2017

Question: Hi guys this is isaaq from UAE.   I HAVE A QUESTION ABOUT MINING.     IS BITCOIN OR OTHER COIN STILL PROFITABLE TO MINE.     I WANT TO INVEST 100KUSD IN MINING.  I WANT TO PURCHASR ANTMINER S9.    PLZ CAN ANY ONE CALCULATE PROFIT JUST NEED RETURN CALCULATE.  AND BREAKEVEN DAYS.  OF MY 100KUSD.   WE MAKE OUR OWN ELECTRICITY.   MY ELECTRICITY COST IS ZERO.     SO IF I HAVE ZERO COST OF ELECTRICITY PLZ TELL ME HOW MUCH TIME IT WILL TAKE TO RETURN MY INVESTMENT AND ALSO TELL ME WHAT IS AVG DAILY INCOME
THANKS
Answer: There are a ton of good calculators out there on the web. Just search "bitcoin mining calculator" on Google and many will show up. Here is my favorite:
https://www.cryptocompare.com/mining/calculator/btc
Answer: Entirely depends.  Most efficient mining gear currently available is the Bitmain (who does offer volume discounts on larger orders btw) S9 running at 14.5 TH.  Electricity costs are by far going to be your most significant cost so depending on what your localities $/KW/Hour rates are.
Currently, where I live for example we pay about $0.096/KW/Hour so mining is still fairly profitable (assuming you can get the units in-hand in a timely fashion), and with Bitmain your basically always purchasing a pre-order.
You might want to consider also looking into diversifying your investment into more than just sha256 gear at this point so your not essentially putting all of your egg's in a single algorithmic basket ;)


Why should I worry about the variance of the return?

Question: I have this doubt (I hope that this is not a completely silly question). If my growth rate depends on the long period average return, why should I worry about the variance of the return? i.e. over the long period, two portfolios with the same average return will grow at the same rate.
Comment: Thanx for the reply, but i have one comment. In my opinion there is a subtle error in your examples. Of course you are performing a mean, but i think that is pathologically chosen. What i  means is that with two only elements, an average is perfectly defined by math, but don't have a full statistical meaning. In other words statistical average say you what is the most probable scenario.
Answer: You do not have to worry about the variance of the return if you do not want to, or if you choose not to. But average long-term growth rate is known only after the fact, not before. Right now, all you can say is that you expect a portfolio to grow at, say, an average rate of 8% per annum for the next 10 years.  Whether your expectations are achieved will not be known till 2022.  The word average is important implying that the growth rate during each of the ten years might be
smaller or larger or the same as 8%, and some idea of how much the annual growth rate might vary from the nominal 8% during the ten years is of some interest to some people. One measure used to describe this variation is the variance (or standard deviation which is the square root of the variance).
Here are some questions for you to ponder.

If you have to choose between two investments, both projecting an
average growth rate of 8% per annum over 10 years, but one is more
volatile so that the actual growth rate in any particular year might
be anywhere from 2% to 14%,
while the other is more stable with actual growth rate in a year ranging
from 7.5% to 8.5%, which would you prefer?
You invest in something extremely risky for a two-year period
(no backsies) and the investment has a 50% loss the first year and
a 50% gain next year.  Is the average gain (-50+50)/2% = 0%?  Will
you get all your money at the end of the two-year period?
Comment: If you say that you can't estimate average return until 2022, then you can't estimate average variance until 2022.
p.s: the mean of 50% loss and 50% gain is not 0. you must compound the return in order to get mean return.
Comment: You can **estimate** that a certain investment will grow at x% per annum with a standard deviation of y% (which might be large enough to have negative growth rates in some years). You have to make the decision **now** and you won't know the **actual** average annual growth rate till 2022. So, if you think that in my first example, both investments are equally good, then you have just answered your own question: you do not need to worry about the variance of your return. In 2022, it you discover that both investments **actually** achieved a growth rate of 8% per annum over 10 years, (continued)
Comment: ...then it does not matter what the variance was; both investments would have earned you 8% per annum. But you might have a few more gray hairs if you had invested in the more volatile investment.
Comment: :) i agree. but my question is at more basic level. If i cannot estimate the return, why i should trust my estimation of variance? i.e. if the estimations are goods, then the return is the most important (Kelly criterion), but if the estimations are not goods then i cannot trust neither on the estimation of the variance.
Comment: Well, then; you have answered the question for yourself; the variance provides no useful information to _you,_ and so there is no need for _you_ to worry about it.
Answer: As Dilip stated, the return (CAGR) will not be the same as the average. For the simple mathematical explanation - (R+x)(R-x) will return R^2-x^2 over the two periods, not the average R^2 result. The higher the variance, the worse the return over time. The issue may be less about this in the accumulation phase then when a retiree is withdrawing funds. I'd prefer the first 10 years of my retirement produce extraordinary returns followed by a below average decade than the reverse.
Answer: I was gonna post this as a comment to Dilip's answer but decided it was worth expanding on, even though some of this has already been mentioned.
If an investment goes down 50% one year, and up 50% the next, even though on average your rate of return is 0%, you're down 25%.
The math:
<code>$100,000 - 50% = $50,000
$50,000 + 50% = $75,000  <-- ouch!
</code>
Some more math:
<code>Both Portfolios start at $100,000. Both have an average annual rate of return of 8%.

Portfolio A - High Variance:
     Year 1: $100,000 down 50% = $50,000
     Year 2: $50,000 up 58% = $79,000 <-- Yay! Average annual gain of 8%!
            Ca-ching! Er... except you're down 21% on your original investment.

Portfolio B - Low Variance
     Year 1: $100,000 + 6% = $106,000
     Year 2: $106,000 + 10% = $116,600 <-- This also has an average annual gain
            of 8%, but instead of being down 21%, you're up 16.6% on your investment!

Which portfolio would you prefer to invest in?
</code>
Now, it's true, that when the investment is done, you've sold it, and you have the cash in hand, it doesn't matter anymore what the variance was over the time that you held it. It's all hindsight then, and nothing more to do except brag at neighborhood parties.
Expected variance is useful to figure out if you should invest to begin with. For any given level of expected return, you want the lowest variance. The lower the variance, the more reliable that expected rate of return is.
So yes, you should worry about variance of return.
Answer: Correct, assuming that one never has to liquidate an asset, its variance is not a risk but an opportunity since foreknowledge of variance would present optimal times when to purchase.
Variance is not the mean, so variance will not impact the long-run return.  This would be the gambler's fallacy, that future random future results will depend upon past random results.
Variance is also geometric, just like the return, so all losses from variance will equal all gains over the long run, leaving the mean for the long run expected value.  In other words, a 50% loss is balanced by a 100% gain which is a simple difference in the geometric scale, so all such losses and gains are equal due to variance.  Since variance is geometric like the mean, a 50% gain is not balanced by a 50% loss.
All of that said, generally speaking across asset classes, the higher the variance the lower the price yet the higher the return.  Variance is a risk because no one is immune from selling at disadvantageous times, and risk is a cost, so that risk must be compensated with high returns.


Photo recovery from a MotoX phone with black screen

Question: I have a MotoX (1st Gen) phone. A few days back my display went black and I am not able to see anything once the phone boots. The notifications are getting displayed on the locked screen, but when I am trying to unlock, the screen is getting black again. The voice command is responding sometimes, but that's about it. I have cleared the cache partition, but that did not help either. Please tell me some way to recover the photos/videos in my mobile.
Comment: Though your screen is not physically broken – not being able to interact with it makes it pretty close in dealing with the issue, so please take a look at our [broken-screen tag-wiki](http://android.stackexchange.com/tags/broken-screen/info), which has a few hints and links on data recovery in comparable situations.
Answer: Your phone still works, so you got lucky.
Plug the device into a PC/Mac and navigate the phone's file directory. Look for the root folder "DCIM". All of your videos and photos should be in there.
Comment: I had already tried connecting my phone to laptop using USB cable. But my laptop is not detecting anything. Only the phone is charging.
Comment: And the device works besides the screen being broken? That's really weird.
Comment: Duh. Do you know where you have to tap to enter your password? You need to get past your lockscreen before the computer will see any files.
Comment: The phone is 10% functional at best. Only the booting and charging are taking place properly. It is showing the notifications and recognising the voice commands sometimes. Only possible solution for recovery that I have found is using OTG cable and use a screen with HDMI input support to turn on USB debugging. But that solution is quite expensive. It would be great if I can get an alternative solution.
Answer: I think this will work.
just go to this website.
https://www.fonelab.com/resource/moto-x-data-recovery-recover-videos-from-moto-x.html
just download the app.
app is only for apple and windows.
this app recovers media.
Comment: Their website doesn't have a physical location for the company, not even a country, and they hide their identity in the domain registration. I wouldn't buy anything from these people or run their software on my computer.
Comment: I agree with Dan. Looking at the software signature it turns out that this product is from "RayShare Co,.Ltd", a software publisher located in Beijing, China (according to some data I found on the net).


DynamicDataDisplay zoom and tooltips on realtime charts with syncronous X axis

Question: Some time ago I posted the question about synchronous charts. I found the solution here, but I still have some problems.

I need to zoom in and out on Y axis on StrokeChart to see my date. I don't know why, but the range doesn't change on next added point. Actually range is 0-1 on Y axis. It's strange, but I can live with that
The second question is: how to configure zoom on chart area? I want it to zoom only Y axis when I scroll up/down.
And last, but not least: How to make realtime tooltips on chart which is build using ObservableCollection? It can be done for EnumerableDataSource easy. you can check this and this. I tried to do thing described by user "Thecentury", but it doesn't work. I even added method AddMapping to ObservableCollection and rebuilt the library, but it still doesn't work. So I don't know what to do next.

I appreciate for any help and advice.
Thank you
Answer: Regarding zooming I think I managed to solve the problem.
In MouseNavigation.cs add new properties
// 2014-02-22 - MPEKALSKI - added property to make possible
                         limiting on zoom on only one axis
private bool? _zoomX;
///
/// Property for allowing/disallowing for zoom along X axis. By default allowed (true).
///
public bool zoomX
{
    get { return _zoomX ?? true; }
    set { _zoomX = value; }
}
private bool? _zoomY;
///
/// Property for allowing/disallowing for zoom along Y axis. By default allowed (true).
///
public bool zoomY
{
    get { return _zoomY ?? true; }
    set { _zoomY = value; }
}

In the same class modify the method
private void MouseWheelZoom(Point mousePos, int wheelRotationDelta)

by substituting
Viewport.Visible = Viewport.Visible.Zoom(zoomTo, zoomSpeed);

with
    // 2014-02-23 - MPEKALSKI - if we do not allow for change in Y
    //                          then keep the old value, by analogy for X
    Rect zoomedRect = Viewport.Visible.Zoom(zoomTo, zoomSpeed);
    if (zoomY == false) { zoomedRect.Y = Viewport.Visible.Y;
                          zoomedRect.Height = Viewport.Visible.Height; }
    if (zoomX == false) { zoomedRect.X = Viewport.Visible.X;
                          zoomedRect.Width = Viewport.Visible.Width; }
    Viewport.Visible = zoomedRect;

The use now is pretty straightforward given chartPlotter object just set properties zoomY or zoomX to false to prevent zooming along this axis.
chartPlotter2.MouseNavigation.zoomY = false;

I do not know is it the most optimal solution, but it works for me.
Comment: http://stackoverflow.com/questions/14314071/dynamicdatadisplay-d3chartplotter-zoom-proplem - there is a build in solution, but it requires scrolling over the axis.


What the best way to upload 20,000 balances to a live parachain

Question: Looking at the best way to upload ~20,000 balances to a live parachain. Assuming will need to upload these balances across multiple blocks. Are there any examples I can of this been done already?
Answer: I don't think there are any tricks here once you have started a live chain.
Generally speaking, you shouldn't mint new funds onto a chain once tokens have been allowed to be transferred. If you have already enabled token transfers, I would not suggest minting new tokens into your economy.
Assuming you already have an account with the funds you want to distribute, you can simply create and submit batches of transfers to move funds to the appropriate accounts.
Comment: Thanks. Indeed balances are still filtered, parachain doesn't produce blocks until next week. Thanks, will batch the transfers. Will see how much I can conservatively fit in each block on test net.
Comment: If you still have the Sudo pallet on your chain, you can use the Root origin to do some of these distributions before you remove the balance filter, but yeah, would still need to batch a bunch of transfers in the end.


Sales vs Sales Console apps in Salesforce - page layout

Question: What is the difference between these two apps and can you create a unique page layout for the same objects for each of these two apps.
Answer: Yes - you can edit the page layout for the different apps. If you want the Accounts page to look different when using Sales compared to using Sales Console, you can just edit the page and assign it to just the Sales app for the Account object. This option is available using Activation button on the top right of the edit page.
The difference from my understanding is simply down to the navigation features. In the sales app, while you are viewing accounts, you can click the link on a related contact and navigate to the contacts tabs to view that contact. Subsequently, the account tab will close. However, in the sales console app, if you are on accounts and click on a related contact, then a sub tab opens up below the accounts tab so that you can switch between the two objects with ease. I guess the difference comes down to preference on whether you want to keep tabs open while navigating for quick referencing.
If there is any more notable differences that I have missed please add.


Xcode not resolving spm dependencies with following error: the package at '/' cannot be accessed (Couldn't read 'x.x.x': fatal: not a tree object)

Question: Xcode is unable to resolve all dependencies added to project through SPM.
One specific spm dependency is causing trouble, so when it is beingf resolved it suddenly stops with error:
<code> the package at '/' cannot be accessed (Couldn't read 'x.x.x': fatal: not a tree object)
</code>
Answer: I was finally able to fetch the version of spm I was after.
Difficult to say what made the trick, as the list of things tried has grown
A combination of removing some of:
<code>derived data
clean project
restarted xcode
restarted mac
reset package caches
package.resolved
Xcode Project Build Caches and Indexes
Xcode caches
~/Library/org.swift.swiftpm
~/Library/Caches/org.swift.swiftpm
</code>
My guess is my machine was in a weird state in which xcode was told that my som spm was cached
But then it tried to get it and it was not there

Xcode not resolving spm dependencies with following error: the package at '/' cannot be accessed (Couldn’t read 'x.x.x': fatal: not a tree object)


How does Stack Overflow control downvoter trolls?

Question: We all have received a downvote on our questions, and for most of them we wondered why. Does Stack Overflow do anything to prevent downvotes made just for fun or wasting their time?
Comment: Yes. Everyone knows that Stack Exchange secretly knows why you're downvoting a post, and they'll remove the downote when they think it's not justified or you were just trolling.
Comment: Check out this blog post. It should answer your question...http://blog.stackoverflow.com/2008/12/vote-fraud-and-you/. If some suspicious voting patterns are detected, they are reversed.
Comment: I'm enjoying the irony that someone appears to have just downvoted all of the answers to this question in an attempt to troll.
Comment: Also how is this a feature request? What exactly are you requesting?
Comment: Related: http://meta.stackexchange.com/questions/135/encouraging-people-to-explain-down-votes
Comment: @Servy I think many could guess who that was.
Answer: For the downvotes on your questions which come in huge quantities from a single downvoter (that is, serial downvoting), there are filters in place which will detect and reverse them. This is afaik a job which runs once each day.
As for the occasional unexplained downvote, no, there is nothing done against those. Nor is there anything that can be done against those. How would you detect that the downvote is invalid? Now, granted, there have been various proposals for mandatory comments on downvotes and downvote validation, but these have all been quite heavily shot down for imho very good reasons. Just have a search through Meta to read through some such proposals. Comments are however certainly encouraged. The basic principle here is that downvoting is a privilege. Once you earn the privilege, you are free to cast your downvotes for any reason, or no reason at all, as long as you're not cheating.
And if you do receive an unexplained downvote, don't just ignore it. Have a good look at your question or answer. Is there anything that might be unclear? Something you can improve upon? A mistake that has gotten into your post? You never know what you might have missed. But if nothing stands out, just shrug it off. Downvotes happen.
Comment: Good answer. I was going to post an answer of my own, but it'd be largely duplicative at this point. I do want to point out the unofficial rule that often comes up on MSO when talking about downvotes, though: Downvoting is a privilege, not a right. Once you earn the privilege, you are free to cast your downvotes for any reason, or no reason at all, as long as you're not cheating.
Comment: @PopularDemand Good point, edited that in.
Answer: There are a number of ways the system helps mitigate this.

The system applies a -1 penalty to the person doing the downvoting (on an answer).  While this doesn't eliminate what you're describing entirely, it certainly makes at least a lot of people think much more carefully about what they downvote; people tend to need to feel quite a bit more strongly about what they vote on rather than voting entirely freely.
Downvotes reduce rep by much less than upvotes increase them.  An upvote is +10 rep (+5 on questions) while a downvote is -2.  There would need to be 5x more trolls than sincere users just to get the reputation to cancel out, and more than 5x more trolls for you to actually lose rep from a quality answer instead of gaining it.
Users are limited to 40 daily votes; this helps mitigate how much "damage" one person can do over a period of time.
SE sites tend to have a strong sense of community.  People tend to notice behavior that they find destructive to the community and actively work to discourage it and mitigate it's effects.  In this case, when people see downvotes on answers that they don't feel are deserved they may go out of their way to upvote a question they would otherwise might not vote on at all to "cancel the vote" or try to draw more attention to the question if they already planned on upvoting just so other sincere users can vote.
There are automatic and manual processes in place to deal with voting fraud.  If you're worried about someone just singling you out and just downvoting your content it's likely to be reversed as serial voting.  If not, they would need to vote on a small enough amount of content (to not trigger the reversal) that it shouldn't be a significant problem.  They can also only vote once per post of yours.  There are also processes in place to detect using multiple accounts to vote (up or down) on the same target person.

While of course none of these things make the problem go away entirely, they do help to significantly limit how often it occurs and the negative effects when it does occur.  What's left after the effects of these factors is something that you can live with, and it's something that most users see at least a little bit of.  Fortunately I've never seen it really be a problem.  It happens infrequently enough, and the effects are small enough, that you really can just ignore it.
Comment: Please don't hand out pity upvotes though. Don't upvote content just because you feel sorry about the downvotes. Upvote because you think the post is worthy of it. I hate seeing a justifiably bad question ending up with a net rep-gain for the OP just because of one or two pity upvotes, when the overall score is significantly negative.
Comment: @Bart I agree.  That's why I took pains to indicate that upvotes tend to not be (and in my opinion shouldn't be) given just because a post has downvotes, but because a post has downvotes you feel are undeserved as per your understanding of the post.
Comment: Sure, I realize you were not indicating otherwise. I just wanted to clarify that point which is admittedly a bit of a pet peeve.
Answer: I would propose a function where you can add a comment to a downvote where you describe why you did so.
Comment: One can simply comment on the post with an explanation (if they want). There doesn't need to be a special kind of comment IMO...
Comment: No, this will never work. They already have the ability to add a comment when they down-vote. If you force them to enter something, most people will just enter garbage. Please see http://meta.stackexchange.com/questions/135/encouraging-people-to-explain-down-votes
Comment: Relevant: http://meta.stackoverflow.com/search?q=downvote+comment :)
Comment: Brilliant idea, everyone deserves to know why they have been downvoted. This is why witnesses need to reveal their identity in court cases in civilized countries.


Does Dell's iDRAC come with its own Ethernet Port?

Question: Does Dell's iDRAC come with its own Ethernet Port, or will I have to dedicate one of my regular Ethernet ports (Broadcom onboard) for the DRAC IPKVM traffic?
Answer: It has it's own ethernet port.
Comment: There are two types of DRAC's integrated, and dedicated. One has its own port, the other piggybacks on one of the on-board NICs. Be sure to specify this when you order your server.
Answer: Dell provide an integrated BMC(IPMI) and basic iDRAC services on virtually all current generation servers as standard - they call this iDRAC6 Express. It does not support out of band Console access (apart from Serial over LAN which is a fairly limited text mode console) and uses one of the onboard Broadcom LOM's. The only current generation Dell servers where the iDRAC6 Express is not a standard feature that I'm aware of are the T110 and the C-Series range of high density systems.
iDRAC6 Enterprise is an extra cost on most systems where it is supported and that adds a dedicated management port, full remote console that supports GUI interfaces, and some other features. The only systems that come with this as standard are the M Series Blade servers.
Comment: Thanks for the detailed explanation. I ordered the iDRAC6 Enterprise. Expensive... $349. But I'm glad it comes with a dedicated port.


Yosemite 10.10.3 has no Photos app

Question: Here's a strange one. I have Yosemite 10.10.3 and no updates required but don't seem to have Photos app. Any suggestions as to how I might get it?
Comment: Please be more specific. What have you tried, what are your suggestions, what is your before experience of photos app (if any)
Comment: It should be included as part of the 10.10.3 update.

Try downloading the combo updater & see if that will add it - https://support.apple.com/kb/DL1804?
Comment: @ TheBro21 I had Iphoto before. I updated to Yosemite and then iphoto stopped working. When I clicked on it, I was sent to the app store, that said iphoto not available for Yosemite in the Uk. I surfed around and discovered I should have the new Photos app instead, which I don't have.
Comment: iPhoto still works under 10.10.3 - it is just no longer supported & will not be updated. It's sounding even more like something went wrong with the update
Comment: I'll cobble together an answer for future Googlers...
Answer: As Photos is supposed to be included in the 10.10.3 update automatically, I would suspect something may have gone wrong with the OS update itself.
In cases like this, I would always try downloading the current combo updater from Apple - currently 10.10.3 from https://support.apple.com/kb/DL1804 but you can always Google for "Apple combo updater [current number]" to find the latest.
The combo updater, unlike the regular delta updater, includes all changes since the last major update, in this case 10.10.0
I would also run Disk Utility & check permissions & drive integrity - before & after running the combo, just to be certain.

Yosemite 10.10.3 has no Photos app


How do I choose which job is featured on my timeline?

Question: I currently work in three places. How can I choose which job appears in my timeline? In my info I have three current jobs and I want to switch the one appearing in the timeline with another one from the remaining two. How can I do that?
Answer: Without explicitly changing privacy settings for the jobs you don't want to appear, it seems Facebook will choose the most recent job.
Example.

Job 1: 2009 to present
Job 2: 2010 to present

Facebook will always choose Job 2
In the case where a user does not fill out the start date

Job 3: (No date shown)

Facebook will still choose Job 2
If one were to change this to 2012 to present
Facebook will choose Job 3.
Let me sum it up: Facebook will choose the job with the smallest time period. You must add a date to have your most recent job appear featured. In other words the job must appear on the timeline to be your featured job.
Comment: Not true. I added a more recent job but my earlier acquired job is still featured. Any else know the actual answer if there is one?
Comment: Sorry to hear that but I have extensively tested these flows. You most likely did not add a date to your job.
Comment: No, the answer is right. If Facebook does not recognise the employer (a photo does not show, etc) it will not be the featured Job.
Comment: It's great to see this explained, and it does fit with my own experience. Too bad that we can't control it, though. Did Facebook remove an ability to set privacy options on individual positions? I can only set privacy for my "Work and Education" section as a whole.


Do Leaflet and turfjs have different projections?

Question: I am trying to use turfjs with leaflet for splitting a polygon by a number of linestrings(using my own algorithm that uses turf.lineIntersect()). It works most of the time ok. but sometimes produces undesired results. Could be something wrong with my logic. I was told that leaflet's default projection system is different from turf's default  projection system. Is it true? I could not find any proof. Do we have to consider projections when using turf with leaflet?
Answer: Turf.js library deals with GeoJSON vector data, so it uses unprojected WGS84 coordinate system, which is EPSG:6326. Since library is used only for calculations and not for data display, that's enough.
On the other side, Leaflet is used for displaying geodetic data, which can be of two types: vector or raster. For operations/calculations with vector data Leaflet uses unprojected EPSG:4326, which is EPSG:6326 with swapped coordinates. That's why all the input coordinates to Leaflet functions are in this CRS. But before this data can be displayed, it has to be projected to flat surface. Leaflet uses WGS 84 Spherical Mercator CRS for that, known also as EPSG 3857.
When dealing with raster data (tiles), Leaflet expects them to be in projected EPSG 3857 coordinates.
So to answer your question, Leaflet and Turf.js use the same CRS datum for dealing with GeoJSON vector data.
If you get unexpected results when cutting polygons with lines, it is result of your algorithm not working correctly.
Remark: Edited to incorporate correction and clarification from nmtoken.
Comment: `The coordinate reference system for all GeoJSON coordinates is a geographic coordinate reference system, using the World Geodetic System 1984 (WGS 84) datum, with longitude and latitude units of decimal degrees.  This is equivalent to the coordinate reference system identified by the Open Geospatial Consortium (OGC) URN urn:ogc:def:crs:OGC::CRS84.` World Geodetic System 1984 datum is [EPSG::6326](https://www.epsg-registry.org/export.htm?gml=urn:ogc:def:datum:EPSG::6326).   EPSG::4326 uses EPSG::6326 but has axes of Lat/long... GeoJSON is not EPSG:4362.
Comment: @nmtoken Thanks! I'm just GIS beginner learning. I know that GeoJSON has swapped coordinates, I just forgot that this means it's not EPSG:4326.


Sharing personal/social information with recruiter or company?

Question: Given the current situation, pandemic, sacking, less job recruitment etc as inhibitors to landing a job, I would like to understand the recruitment mindset of companies. For quite some time now, I have been searching for a job. I have observed a recruitment pattern, wherein, smaller companies would offer a certain technical question to complete as a pre-assessment exercise. While established companies, would rather collect candidates demographic information including their social data like parents name and contact number, friends contact number in case the candidate is not reachable. What I fail to understand is the reason to collect such specific information from the candidate? So my question is,

Should I share such sensitive information with a company right at the beginning of the recruitment process or not? Please explain the reason.
What is/could be the underlying reason to collect such specific information?

I have already seen a similar Q asked but can't find my answer there.
Comment: If I received a task similar to that, the company would find that most of my friends & family have starred in Disney Movies in the past..
Answer:
Should I share such sensitive information with a company right at the beginning of the recruitment process or not?

Absolutely not. The only reason a company needs your personal details is to know who to contact in case of emergency; until you're actually an employee, they're not going to do that.

What is/could be the underlying reason to collect such specific information?

By far the most likely explanation here is that the "recruiter" is a scam.
Answer: This answer is meant as complement to others rather than standalone. Assuming you appply to tech I strongly suggest to ommit your graduation year, any "era-specific", obsolete skills such as adobe flash, silverlight, vba and etc. Try to not include skills/positions older than decade, unless you are sure that employer is not superficial, values skill and won't judge you as overqualified.
Answer: I think it's unlikely these established companies are are hiring based on demographic information.  However, large companies often have whole departments dedicated to social responsibility. Under this banner they will have environmental initiatives (e.g. drive to be carbon neutral) or charitable goals (e.g. fundraising for a chosen charity or setting days aside to volunteer in the local community).
They are also likely to have socially conscious objectives. These include things like aiming to have women make up at least X% of management at all levels or hiring people with disabilities, from socially disadvantaged communities or from ethnic minorities.
This departments will have goals and KPIs they want to track against. If the company has a reasonably public profile they may want to collate the data for PR and media purposes. That might explain why they ask when your live, your education levels, ethnicity etc.
I don't, however, think this should allow them to request contact numbers of friends and family until you are an official employee when they would need next of kin information. (Unless they were going to call your mom to ask for a reference!).  I'd be inclined to politely refuse that information on the basis that you don't have the explicit permission of the friend/family member to give their number to anybody.
Answer: It indeed seems preminilary and a bit prying to ask for contact information of your intimates and other demographic information before you even work at a company. However is there a likely scenario where this information can/will be abused? Especially if it are big and well known companies with a reputation to uphold? Most of this information can probably be gathered from your Facebook profile anyway.
I guess it's best to consider these untimely questions just as a quirk that comes with the bureaucracy in large companies. For situations as these, the saying "Pick your battles" was invented. So summarized, don't let a good opportunity pass because of these questions.
Comment: thank you for an alternative opinion.
Comment: It is extremely likely that some information will be abused, especially one that can be used to infer age.


looking for hadith reference on reduced blessing on sustenance for eye zina

Question: a scholar told it is found from hadith research that you blessings(baraqah) are lost in rizk for eye zina. where did he find that from? can anyone give me hadith number referring to this?
Answer: There's only one Sahih hadith in which the "eye zina" term is mentioned, that is:

Abu Huraira reported Allah's Messenger (ﷺ) as saying. Allah fixed the very portion of adultery which a man will indulge in. There would be no escape from it. The adultery of the eye is the lustful look and the adultery of the ears is listening to voluptuous (song or talk) and the adultery of the tongue is licentious speech and the adultery of the hand is the lustful grip (embrace) and the adultery of the feet is to walk (to the place) where he intends to commit adultery and the heart yearns and desires which he may or may not put into effect.

And it does not mention anything about Rizk.
However, there is a Daif Hadith that says: "Zina causes poverty" الزنا يورث الفقر. It was reported in Silsalat al-Hadith ad-Da'ifa by al-Albani no. 140ـ 143


Find Maytag Upright Freezer Coils

Question: How do I access the freezer coils? Do I need to remove the door? Photo is of the front of the freezer.
Comment: The evaporator coils in an upright are usually in the back behind a panel that controls the air flow. The condenser coils can be under the exterior skin or under the bottom of the unit. Your model and why you are looking for a coil may provide answers with useful information.
Comment: Hmm...re photo. MZF34X16DW00
Comment: Added photo again!
Comment: I would like to clean the coils. It is 5 years old and is not holding temperature. It is at 30 degrees.
Answer: Cleaning would I dictate condenser coil.
You will have to pull it out, there is usually a section at the bottom it may have a cardboard cover.
On some units there is a fan, this fan can fail cleaning the area and lube of the fan bearings can revive a fan that may not be doing its job, dirty coils can also reduce the efficiency.
The worst plugged up fan I have ever found had a mouse (dead) stuck in the fan stopping it from turning.
These motors are normally shaded pole and hard to kill if the fan is not spinnng a few drops of light oil on the bushings at either end should help it. These are oil lite "bearings" and there is a wick that is filled with oil the bronze bushing is wetted by the oil and they usually last for years, if stuck adding oil and spinning by hand usually will revive them. The more oil you can get to soak into the wicks the longer it will work. ( I take them apart and Saturate them and get 5 years usually.)

Find Maytag Upright Freezer Coils


Use of the passé simple

Question: Is the passé simple used in spoken French at all in regions other than France, such as in Canada or in Africa? I know that it has largely fallen out of use in speech in France itself, but do these former French colonial areas maintain the use of the passé simple or of other historic grammar constructions?
Comment: Note that it has fallen out of use in France only in spoken french.
It is still in use in written french in France.
Answer: In Canada, in the province of Québec, we do not use the passé simple in spoken french. We use passé composé instead.
We do however use it in litterature. Even then, we see it as formal and a lot of contemporary novels are written using passé composé. I would even say that it sets the tone of a book.
Comment: I'm from Montréal. I sometimes use the "passé simple", but in a comical way, the same way I'll use the "subjonctif imparfait". And with people who are apt to understand that I know that they know what I'm doing.
Answer: My wife is from Benin and I've never heard people there use the passé simple in everyday life. I suppose it is also true for most of French-speaking West Africa. West Africans can have more "châtié" French than French people though.

Use of the passé simple


Will Time Machine work effectively with a WD MyCloud NAS device?

Question: I recently purchased a Western Digital MyCloud NAS device. I'm wondering if there would be a problem with using it for backups with Time Machine on a Mac mini (late 2012) running OS X 10.9.5. Is there anything I should know?
Answer: I've had the same issues as Evert. I have now given up and pulled the plug on my WD My Cloud. Although I have seen that some people are getting on okay with it, most of what I have read concurs with my own finding. It is no good as a time machine back up. It is terribly slow. My last successful back up, which added approx 250gb to my already backed up 1.25tb took 7 days. Prior to the verification messages now encountered I would wait a day or two to get passed the 'Preparing data' message. I can no longer even access the wd my drive as a timemachine and it no longer recognises the info, even though the amount of space on the WD cloud drive indicates the backed up info is still on there.
I am converting back to a usb external hard drive.
I would recommend buying anything rather than the WD MyCloud if using it with a MAC.
Answer: According to what I read there should not be any problems.

By default, the server comes with three public share folders called
  Public, SmartWare, and Time Machine Backup. As the names suggest,
  the Public folder is for storing public data, and the other two are
  for backups of Windows and Mac machines, respectively.
As soon as the device is plugged in, all of these public folders are
  available to all connected devices in the home network. From a Windows
  computer, you can browse for these share folders and copy data (such
  as digital content) over. Macs will immediately see the My Cloud as
  an available destination for Time Machine backup and the My Cloud will
  also appear on Finder. All DLNA-enabled network media player
  devices, such as the WD TV , will also immediately find the content
  stored on the My Cloud for streaming purposes.

Source: http://www.cnet.com/products/wd-my-cloud-2-tb/
Here are some instructions how to set it up.
Comment: Thank you, Buscar, I'll research the links you provided.
Answer: I've had very negative experiences with it. It works for a while, but then Time machine will always complain that verification failed and has to re-create the entire backup from scratch every time. There appear to be others with the same issues as well, so I would not recommend this for Time Machine. Very possible that the issue is on Apple's end though.
Answer: In practice, it keeps on crashing my backups, and I have to delete them so often, that I would advise NOT to buy one....
Answer: I searched for evaluations like this before purchasing, but not searchingly enough, I guess.
Pros
Western Digital's own syncing and backup to the NAS software is pretty cool so far.
Con
After purchasing in January, 2016 with the latest software updates, I experienced glacial Time Machine performance with hours and hours spent preparing backups. Then when I got a full Time Machine backup, Time Machine refused to recognize the Time Machine share on the NAS.
Buyer beware!


Is it possible to make an AutoUpdate feature in any of iOS App

Question: i need to implement an autoupdate feature in my iPhone app like if i released a version 1.0 then i upgraded it to 1.1 then who ever the users using 1.0 in there devices in background my update has to run.
I know that there is an in-App Purchase, APNS feature but rather than that is there any other way to achieve this.
Answer: Nope, all updates has to be in the App Store in the first place.
You could "auto-update" your app if your principal frame is loaded directly from the Internet.


Is there a way to find out how often your furnace is running?

Question: With winter finally setting in, and being the first year in our new house I would like to put some sort of measurement on how often the furnace is working, before I get the bill.  Are there any known methods of measuring how much fuel furnace is consuming, other than monitoring the gas meter outside the house?  What is the best way?
Comment: What exactly do you mean by "how hard"?  They are not humans - they are either on or off, for the most part.  Are you asking about efficiency?
Comment: I have a programmable thermostat, and the temperature changes dramatically from day to night.  Looking for insight into methods/tools to use to monitor the furnace and when its on.
Answer: Some of the more advanced thermostats will track how often they are running.  I have a Filtrete Wifi-Enabled Progammable Thermostat.  It gives you a per-day total of how often the heat and A/C are run.  You can also download an hour-by-hour export of the usage in CSV format.
I am in no way affiliated with this company. It is simply a product I have installed at home
It also gives you an idea, for a given temperature change, what the % change in heating cost will be:
Comment: There is also a JSON API that you can use to get the runtime for the current and prior day directly from the thermostat if you like to write code.    Here's the beginning of the current output from mine: `{"today":{"heat_runtime":{"hour":1,"minute":1},`
Comment: I love this thing!  There is an android app, iphone app, ipad app, cloud management.. and for $100, how can you go wrong?!  the only thing you need to verify is that you have a wire at your thermostat connected to your furnaces C terminal.  If you do not you either need to run an new wire or use a transformer to power the thermostat.
Comment: I really like this, and I'm debating just buying one given the price is right.. for now I might just take meter readings until I see other options as well. +1 nice tool
Comment: Question, does this model have inputs for a humidifier as well? We have an old Aprilaire attached to our furnace with a control unit right next to our current humidifier.
Comment: It does not but the CT80 model does: http://www.radiothermostat.com/control.html
Comment: I see a StackOverflow thread starting :)
Comment: I'm going to have to get the CT80 model :D
Answer: Most furnaces have an AC component that is powered on when it is running.  Put a ac clock in parallel with this.  For up to 12 hr this will tell you the time the device is running.  Other types of timers will go for longer.  Most furnaces run at two speeds stop and full.


Using Python Search Cursor results to Select Features by Attributes

Question: I would like to preface this by saying that I am very new to python and its capabilities. So my problem is that while using the in_memory work space I encountered some limitations in querying the minimum value for a field. My workaround for this was to create a dictionary, then use a the search cursor to find the minimum distance. My method returns the results that I am looking for but I have not been able to incorporate these results into my selection. Below is a snippet of the code I am currently using:
# Process: Near
    arcpy.Near_analysis(newStationLayer, targetPoint, "", "NO_LOCATION", "NO_ANGLE", "")
    nearDist = {}
    with arcpy.da.SearchCursor(newStationLayer,("OID@","NEAR_DIST")) as cur:
        for row in cur:
            nearDist[row[0]] = row[1]

    arcpy.AddMessage("Near distances: %s"%str(nearDist))

    ## arcpy.AddWarning(min(nearDist.iteritems(),key=operator.itemgetter))
    lowestOID = min(nearDist,key=nearDist.get)
    arcpy.AddWarning(lowestOID)

    arcpy.SelectLayerByAttribute_management()

Comment: Are you asking what goes inside the () for the SelectLayerByAttribute line?
Comment: Yes that is what I am trying to determine. I have tried many different configurations but to no avail.Its probably something really simple that I'm just missing when thinking it through.
Answer: A really simple way to get the minimum value is to use TableToNumPyArray to convert your table to a numpy array then use numpy functions.
from arcpy.da import TableToNumPyArray
import numpy
na = TableToNumPyArray(newStationLayer, "NEAR_DIST")
numpy.min(na['NEAR_DIST'])

You can combine this directly with SelectLayerByAttribute_manager.
from arcpy.da import TableToNumPyArray
import numpy
field = "NEAR_DIST"
na = TableToNumPyArray(newStationLayer, field)
arcpy.SelectLayerByAttribute_management(newStationLayer, where_clause='"{}" = {}'.format(field, numpy.min(na[field])))

In that last statement, I am using the string format function to insert my field name into the where clause and to insert the results of calling numpy.min on my table array. For example, if your minimum value was 80.0, the where clause would become '"NEAR_DIST" = 80.0'.
If you get the error:
ExecuteError: Failed to execute. Parameters are not valid.
The value cannot be a feature class
ERROR 000840: The value is not a Raster Layer.
ERROR 000840: The value is not a Mosaic Layer.
Failed to execute (SelectLayerByAttribute).

It means that newStationLayer is a direct reference to a feature class and not a layer that you can apply a selection to. You will have to add something like:
layer = arcpy.MakeFeatureLayer_management(newStationLayer)
arcpy.SelectLayerByAttribute_management(layer, where_clause='"{}" = {}'.format(field, numpy.min(na[field])))

I just had a chance to test this, and this is the right format for an in_memory where clause. Your reference to newStationLayer needs to be a reference to the layer in the map though and not a direct reference to the in_memory feature class! (Otherwise you will get the error I talked about above. arcpy.MakeFeatureLayer_management will add a new layer to the map using your in_memory feature class.)
Answer: I always do this using a function that I originally found on stack exchange.  It builds a where clause for you, and works with lists.  It's nice, because it uses the add field delimiters function and therefore you dont have to wory about what type of data you are using (shapefile, fgdb, etc.).  Just add this to your code somewhere and then call the function to to create your where clause.
def buildWhereClause(table, field, valueList):
    fieldDelimited = arcpy.AddFieldDelimiters(arcpy.Describe(table).path, field)
    fieldType = arcpy.ListFields(table, field)[0].type
    if str(fieldType) == 'String':
        valueList = ["'%s'" % value for value in valueList]
    whereClause = "%s IN(%s)" % (fieldDelimited, ', '.join(map(str, valueList)))
    return whereClause

When you need your where clause:
whereClause = buildWhereClause(newStationLayer, "OBJECTID", [lowestOID])

And then:
arcpy.SelectLayerByAttribute_management(newStationLayer, "NEW_SELECTION", whereClause)

I did the selection parameters from memory, if it's not quite right you should at least get the idea.
Comment: As a side note.  I have this function as part of a module of custom functions that I import for almost every script I write.  This way I don't have to add it everytime, I just import the module and call it when needed.


Proving existence of multiplicative inverses for certain sets with multiplication defined modulo $ n $

Question: Let $ Z_n=\{0,1,2...n-1\}$ and multiplication be defined modulo $n$ . I have to find the $n$s for which all non zero elements of  $Z_n$ have a "multiplicative" inverse from within $Z_n$. I conjectured that all prime $n$s fit his category and its easy to show that only primes can do so ( as it is impossible for any non $1$ factors of $n$ to have an inverse). But how can I show that ALL primes fit this category ?(And if they dont then how do I find out which $n$s do?)
Answer: Suppose n is a prime and m is an element from $Z_n$. gcd(m, n) = 1, so there exist a and b so that am + bn = 1 (why? just see the working of Euclid's algorithm). (a mod n) is then the inverse of m from $Z_n$.
Comment: Apart from their existence its also necessary that a be positive and b be negative or else the remainder when divided by n will be "-1" instead of "1" (technically speaking) i.e. not 1 at all right ?
Comment: Not at all, if a is negative say a = -b then of course b mod n is not the inverse but I am talking about a mod n, which is the inverse. Let me take an example: m = 3, n = 7. The equation is: (-2)(3) + (1)(7) = 1. -2 mod 7 = 5. 5 is the inverse of 3 modulo 7.
Answer: The numbers you are looking for are those $a\in \{0,1,\cdots,n-1\}$ for which $\gcd(a,n)=1$.
In fact, for any such number, it is well known that you can find integers $r$ and $s$ such
that $$ar+ns=1.$$
Now reducing ($\mod n$) both sides of the above equality, you get
$$\overline{a}\cdot \overline{r}=\overline{1}$$
That is,  $(r \mod n) \in \{0,1,\cdots,n-1\}$  is the multiplicative inverse of $a\in \{0,1,\cdots,n-1\}$.
Answer: Hint $ $ The following may help to comprehend, step-by-step, why the equivalence holds, by using  $\,\rm\color{#c00}{P} = $ Pigeonhole principle (where all congruence arithmetic is $\!\bmod n$)
$$\begin{align} &\color{#0a0}{ab\equiv 1}\, \ {\rm for\ some}\ b \ \  [\![\text{ i.e. $\,a\,$  is } {\bf invertible}\,]\!]\\[.4em]
\iff\ &a\mapsto ax\ \ {\rm is\,\ onto\ \ \ \ \ Proof\!:\ (\Leftarrow)\ \ clear.\ \ (\Rightarrow)\ \ } c \equiv a(bc)\\[.4em]
\smash[t]{\overset{\rm\color{#c00}P}\iff}\ \ & a\mapsto ax\ \ \rm is\,\ 1\!-\!1 \ \ \ \ \ [\![\,\text{ i.e. $\,a\,$  is } {\bf cancellable}\!:\ ax\equiv ay\,\Rightarrow\, x\equiv y\,]\!]\\[.4em]
\iff\ & ax\equiv 0\Rightarrow x\equiv 0\ \ \ \ [\![\,\text{ i.e. $\,a\,$ is }{\bf\text{not a zero-divisor }} {\rm i.e.}\ \ker(a\mapsto ax) = 0\,]\!]\\[.4em]
\iff\ &\  \color{#90f}{n\mid ax\,\Rightarrow\  n\mid x}
\end{align}$$
So, by above, all $\,a\not\equiv0\,$ are $\:\!\color{#0a0}{\rm invertible}\bmod n$ $\iff [n\nmid a,\,\color{#90f}{n\mid ax\,\Rightarrow\, n\mid x}]\!\iff n$ is prime, by Euclid's Lemma.
Comment: See also [here](https://math.stackexchange.com/a/2383809/242).


Big O notation, code time complexity

Question: does appending an element to a list through a for loop work in O(1) time or O(n) time? In addition, what is the time complexity does "".join that list into a string work in?
Comment: Hello, welcome. A list is an abstract data structure. The time complexity depends on the particular implementation. If you are asking about a specific language or implementation of lists, you would want to try StackOverflow or another site.
Answer: It totally depends upon the particular implementation. In linked-lists which support circularity (where the first element, possibly a sentinel, links back to the last one) the task can indeed be achieved in $O(1)$ time, for it requires fetching a pointer to the tail of the list; on the other hand, on implementations which do not support doubly-linked elements or other fancy mechanisms, a full iteration to the back of the structure might be necessary, thus requiring $O(n)$ time.
On a side note, the term list refers to an ADT (Abstract Data Type), which is merely a type coupled with a set of operations and specifications. Thus, the term list does not inherently have to be linked to the pointer-based implementation; in fact, an ADT implementation such as Java ArrayList may be also realized on arrays, giving a random-access time complexity on any location (including the tail) in $O(1)$ time.
Answer: For the first question, based on the fact that you're appending using a for loop it implies that you're doing it in O(n) since you'll loop at most n times where n is the current length of the list.
The time complexity for "".join() in Python is O(len(list)) since it'll have to iterate through the list once while creating the string.

Big O notation, code time complexity


Does the anwer 13305 to "Has mu'tah been forbidden via the Quran? (Sunni view)" precisely address the question?

Question: Does this answer to Has mu'tah been forbidden via the Quran? (Sunni view) precisely address the question being asked? And why?
Does it need further improvement? And if so, how?
Answer: By the looks of it, the post took a fair stab at answering the literal question in the title (I lack the domain expertise to know how well it represents any actual Sunni view), but fails to actually answer anything in the question itself.
The question clearly goes in accepting the fact that Sunnis forbid mut'ah, and doesn't indicate any confusion on that point.  The crux of the question is based on the apparent conflict between the clear hadith claiming that Allah has forbidden mut'ah and the lack of a clear corresponding prohibition in the Qur'an itself.
The answer, however, doesn't make any effort to address this aspect of the question; the whole post looks to be answering "Has mut'ah been forbidden via the Quran?" by tack of proving that it hasn't been forbidden at all.  Which, as I read it, is not at all what the questioner wanted.
Perhaps the question should be fixed so the title better matches the actual body of the question.  But the posted answer does not appear to be any answer to the actual question, and should probably be removed as such.
Answer: I now agree that my answer doesn't specifically answer the actual question, but what prompted me to answer it was the assumption that according to mainstream Sunni school, Sura Nissa:24 is interpreted as allowing Muta, and why I saw that the Sura Mu'minooncan:5-7 which is used as an evidence against mutah, could've not made Nissa:24 obsolete as it revealed much earlier. My assumption was, though, rejected.
Having said that, I agree that my answer doesn't fit the question! Should I now delete the answer myself or wait for community action?
Comment: [Of relevance.](http://meta.softwarerecs.stackexchange.com/q/732)


Is publication an important criteria to get a post doc in microbial ecology?

Question: I am a researcher in microbial ecology , currently searching for post doc in European countries. I have publication less than 1 impact factor. Will this hinder my chances of getting selected . Please suggest?
Comment: Welcome! You might get a good answer (or find a similar one answered) on http://academia.stackexchange.com ; Personally, I would recommend to rephrase your question slightly to invite recommendations that will help you further (rather than getting a yes/no answer), e.g.: "Only published in low impact journals - how to maximize chance to do a PostDoc position in Europe?". You could possibly also add other information (e.g.: whether other students in your current department publish similarly).
Comment: We can also migrate the question to academia, if you want to.
Answer: I agree that this is not the best community for this question, since it is not really about biology. But to give a glimpse of an answer:

Having publications in high rated journals certainly increases your chances of getting a postdoc position.
It also depends on the general level/rate of publications in your field: in some fields having a few publications after a PhD is normal, while in the others the first publication may appear in press years after you graduate (not counting the thesis).
Then again, a publication in a top journal does not necessarily testify to one's abilities - e.g., if you are one among a few dozens of authors.
Networking and personal recommendations are often as important in getting positions as having publications.


Restore Service Master Key w/Existing Encryption Data

Question: I recently implemented database encryption using Symmetric/Asymmetric keys and have the Database Master Key (DMK) encrypted by password.  Now if I'm understand the encryption hierarchy correctly, the DMK password will then be stored in the master database and is encrypted by the Service Master Key (SMK). My goal is to copy the database to another server to serve as a "test environment".  In order to do so, I'll need to restore a copy of the Service Master Key on the destination server in order to properly encrypt/decrypt the data.  I just want make sure that I'm reading the documentation correctly regarding the RESTORE MASTER KEY command.  When I restore the SMK, any encrypted data on the destination server will first be decrypted by the current SMK and then re-encrypted using the new SMK.  Is it safe to assume that no other database should be adversely affected if they have encryption?
Answer: Looking at the syntax for CREATE DATABASE ENCRYPTION KEY, the database master key (DMK) is encrypted by either a server-level certificate or a server-level asymmetric key. In order to restore that database on another server, the certificate or asymmetric key that protects the DMK needs to be present in the master database at the destination. Once you have that, you should be good to go.
If this is a cross-environment restore (e.g. prod → dev), I like to re-encrypt the key with an encryptor that doesn't exist at the source. It's a little added protection that ensures that the restore happens one way (i.e. you can't overwrite prod with dev).