Symbols to avoid while creating new commands

Question: I experienced some problems when creating \newcommand that have some numbers in their names; I can't find docs about that, about the accepted charset for the commands in LaTeX.
Comment: Please see also: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=linmacnames
Comment: You can use `\@namedef` and `\@nameuse`. Or the package etoolbox provides similar commands.
Answer: You should use only the letters A-Za-z in the user commands.  Commands defined in .sty file (or inside \makeatletter/\makeatother pair) may include @.
If you need numbers for a set of related commands, the usual practice is to use roman numerals, like \fooi, \fooii, \fooiii, \fooiv, etc.
Comment: Thanks for the Roman numeral suggestion! I had been writing things like `\fooOne`, `\fooTwo`, `\fooThree`!
Comment: @JohnJamesSmith - The idea is not mine: it is from plain.tex...
Answer: A command name can consist either of one non alphabetic character or a sequence of alphabetic (A-Za-z) characters.
Actually the rule is a bit more complicated, but as far as the final user is concerned, this is can be considered the truth.
So you can't say \newcommand{\a1}{...} because the name a1 is not a legal command name. Macho TeX programmers know ways to overcome that restriction, but it would be ininfluent for the final user that wouldn't be able to say \a1, as distinct from \a232, anyway.
If you have in mind some application of command names with numbers, please modify your question so that somebody can suggest you a better alternative.
Answer: There are two basic "flavors", to use Knuth's own terminology, of control sequences in TeX/LaTeX:

A control symbol, consisting of a backslash, \, followed by a single nonletter character. Examples: \\ (newline), \' (sharp accent in text mode). [For you TeX purists out there: I know that, strictly speaking, it's an "escape character" that starts the control sequence, not necessarily a backslash. However, it is near-universal practice to use the backslash character, and only the backslash character, as the escape character.]
A control word, consisting of a backslash and one or more alphabetic characters (i.e., no numerals, no other non-alphabetic characters). Examples: \textbackslash, \def. Note that TeX and LaTeX are case-sensitive, hence \hello and \Hello won't be the same commands.

Control words may be further differentiated as those that include one or more "at", @, characters and those that do not. The former control words are (and should be) used mainly by TeX and LaTeX programmers for macros and variables which users should not access or manipulate directly; this is achieved by making the @ character "special", in a well-defined sense. However, when one must change some existing macro that contains one or more @ characters, one can do so by first typing \makeatletter to suspend the "specialness" of the @ character, performing whatever further instructions that are required, followed by a \makeatother instruction to restore the "normal" behavior of the @ symbol.
Given the preceding explanations, it's clear that what you've run into is the fact that you should not be using numerals (or any other other nonletter characters) in a control word. (If you think you simply must use some numbers in the macro, you can write them out as, say, \choosefirstoftwo, \numberten, etc.)
Answer: You can only use characters in macro names which are officially marked as letters. By default only real letters a-z and A-Z are marked this way.
You can however, change this by changing the category code (catcode) for the character to 11 (letter). This is done to the @ character for all packages and class files. In user documents you can do this manually using \makeatletter and switch back to normal using \makeatother after you have defined all required macros. This is done to keep internal macros untouchable in normal user document to avoid accidental name clashes.
You could change the catcode of virtually any character to 11 and then use it in a macro name, but this may cause issues. (The LaTeX3 project for example uses : and _.) The best thing is to stick with normal letters and use 'a', b', etc. or roman numbers instead of numbers.


How do I describe this particular scene?

Question: My character lives in a war torn country. I'm trying to start this short story with him waking up on his way to school (possibly the bus stop). On his way, he sees graffiti, vandalism (basically thrashed cars and windows), bullet shells, etc. lying around everywhere. I'm writing this in first person and have yet to actually figure out how to put everything together. Any help would be appreciated.
Comment: This question, in my opinion,
leans towards 'what to write' which is not on topic for this site.
Comment: Sorry about that, but I'm actually looking for more of a "how" then a "what" in this particular case. Where would you advise posting it?
Comment: Whether it is "what to write". or "how to write", you are very close to asking someone to write your story for you. I am afraid that the only advice which you can expect is: "find words, then put them in sentences, then read and edit, until you are satisfied with the results". The craft of writing is not that different of all other crafts, in order to learn how to write, one must practice. It looks like you already have a picture in your head--just describe what you see.
Answer: You describe very well what the main character sees.
Next, how do they feel about what they see?
What is new? Old?
What has changed since yesterday/ever? What has not?
Do they wonder Why? Who? When?
How are they connected to the scenes/environment they experience?
Is there anyone else with them; what do they say?
Do they contrast/agree with what the main character experiences?
...


How to fix relationship lines?

Question: Sorry i'm new to blender so i dont know how can i word this question better. I just learned that these dotted lines relationship lines. So i guess they show parent-child relationship between objects but in this case its not what i expected it to be. I have this door here whose relationship line goes to the origin even after i clear its parent (alt+p >> clear right?). even if i set parent of the door the doorframe object which is around it (select door>>then select frame>>ctrl+p>>object), the relationship line from the door still keeps going to the origin. This looks and works ok in blender for some reason but i want to export this model as fbx to unity. In unity, these doors dont show up at all.
Answer: As you said you've tried Ctrl+p, so the door is not a child of any object.
Then the only thing that can cause this problem is that the origin far away from the door. Select the door, press T > on left hand side menu set "Origin to Geometry".
If it still doesn't work, share the blender file with us or recreate the problem (if you can) in a separate project and share that file.

How to fix relationship lines?


Double play in baseball

Question: The bases are loaded and the ball bounces in front of the third baseman. He picks up the ball and touches third for a force-out on the runner coming from second base. Can he throw home for another force out or can the runner who was on third return to third?
Answer: This is covered by MLB rule 5.09(b)(6)
From 5.09(b)

5.09(b)
Any runner is out when:
[...]
(6) He or the next base is tagged before he touches the next
  base, after he has been forced to advance by reason of the
  batter becoming a runner. However, if a following runner is put out on a force play, the force is removed and
  the runner must be tagged to be put out.

Since a following runner is out, the runner from third must be tagged out while not touching a base.
Answer: When the third baseman touches third to force out the runner coming from second, he removes the force at home. The runner going home must be tagged out and may choose to go back to third because the force has been removed.

Double play in baseball


Am I in risk of being banned?

Question: I was going to ask another question today, when suddenly I received a warning in the 'Ask Question' page that I was in risk of being banned(or muted or something similar. It disappeared before I could read correctly).
Well I know that some of my last questions weren't exactly accepted with great enthusiasm, or 2 were put on-hold, but I wouldn't think they are banning material.
Should I take the warning seriously?
Comment: The same problem is discussed [here](http://meta.mathematica.stackexchange.com/questions/1304/preview-a-question-to-ensure-its-appropriate/1305#1305). It's a case of a computer trying to gauge the quality of your questions and failing at it. Plus it seems to misunderstand how suspensions are used on this site.
Answer: Update
Sometime (I believe) after writing the reply below automatic blocking was added to the system, as indicated by notices added to the community moderator tools panel.  As far as I can tell community moderators (like me) do not have the ability to rescind this automatic block; it must be waited out.

As far as I know we do not have automatic question bans on Mathematica.SE though they do exist on e.g. Stack Overflow as described here: What can I do when getting "We are no longer accepting questions/answers from this account"?
An account may still be manually suspended for a number of reasons including "consistently low quality questions over time."  Briefly reviewing your question history it does appear that you have a higher than normal closed and/or deleted percentage.  Although not all cases are problematic I think it would be beneficial for you to read this again and consider the close reasons on some of your closed posts.  Mostly I think you just need to become a bit more familiar with Mathematica, both the site and the software, before things flow as well as intended. :-)
Comment: @Mr.Wizard I thought I had heard that the [new temporary question bans](http://meta.stackoverflow.com/questions/271542/why-wont-the-system-allow-me-to-ask-questions-for-several-days) were active on all sites now, but I'm not sure.
Comment: @Jesse Also related, please see this meta Q&A: [(274)](http://meta.mathematica.stackexchange.com/q/274/121) -- hopefully the majority of your questions will not fall into the "blatant RTFM" category but even if they occasionally do it may be OK if they are well written as there is often a nontrivial or nonstandard method that can be shared.
Comment: Ok, thanks for the heads up. I'll give my best.
Comment: This is a bit late, and I haven't been hot with a ban threat. But maybe a deeper question is how the site handles stuff from noobs? Like me, for instance. I have little experience with Mathematica and a couple of times needed what seemed like elementary help (syntax stuff). But a "simple" syntax problem to a newcomer is NOT simple, and the explanations in the documentation are often worse than useless, since they assume knowledge a newcomer will by definition not have.
Comment: @Jesse In my opinion the most important thing is to write a good question.  First search the site to make sure that you are not asking what has already been asked *in the same wording*.  Then write a clear, reasonably brief question with sufficient examples of any code that is troubling you and also exact input and output that you desire if applicable.  Such questions, even if later closed, are generally welcomed by the community unless it appears that you are attempting to use the site as a *replacement* for the documentation, in which case you will be instructed to read introductions etc.

Am I in risk of being banned?


Achieving the Expected SG from a Beer Recipe

Question: I've recently been looking at all-grain brewing and noticed that the recipes tend to have a wide variation in the expected final specific gravity after fermentation. I was wondering how you manage to hit these varying S.G. targets if the yeasts job is to convert sugar to alcohol. Is there some other factor at work here ?
Answer: The short answer is that happy and healthy yeast are a critical component to reaching your target S.G.
Of course, this all begins with where your O.G. is based on your grain bill and mash temperatures.
Your S.G. will be determined by the complexity of the sugars that made it to your fermenter, based on the mash schedule used. A slow ramping up of temperatures tends to create a wort with much simpler sugars. The simpler the sugar, the more easily it is consumed by the yeast.
Different strains of yeast can process different types of sugar. Most ale yeasts tend to stop consuming sugars that are bigger than maltotriose. Brett yeasts by contrast, will consume pretty well any sugar source, including the lignin that makes up wood fibers! French Saison Dupont strains are notorious for indefinitely pausing fermentation at 1.020. So yeast selection is important, such that it matches your wort profile, i.e. lager vs berlinerweisse.
Furthermore, different yeast strains will have different attenuation, this is the degree of completion to which they complete the fermentation. If you look at the supplier's website for the yeast for your next brew, you will see this information listed.
The yeast you employ will perform best if they are happy and healthy, with reduced stress. It is therefore important to make sure your wort is well aerated, you are starting with a viable and vital yeast culture and that your wort conditions are favourable for the yeast. Variables such as pressure and temperature come into play, and can be used to tailor the yeast towards making clean or estery (aromatic) beers.
Tools like Brewer's Friend Recipe Calculator can help you get started by putting in your recipe and selecting different yeast strains to see where you might end up.
Answer: Mash temperature and grist composition play the largest role in final gravity.  The key is to control the fermentability of the wort.
Answer: Mash Temperature is the criticial component when targeting a final gravity. When I'm making a stout I shoot for a higher mash temperature in the 153/154 range. while if i want to dry out a pale ale 149-151 degrees F in increase B~Amylase activity and allow a higher finishing gravity. A couple of other things that could be affecting your final gravity is your pitch rate and/or lack of wort oxygenation pre-fermentation. If you don't oxygenate your wort well enough before pitching, your yeast will set up weak cell walls and reproduce weak hungry offspring that will autolyze early. try using a yeast nutrient like servomyces and a food grade oxygen through a sanitary oxygenation stone. it's always better to over pitch than to underpitch. if your fermentation temperature is too far from where it should be your gravity will suffer. And a less likely cause is a clogged blow off hose. Fermentation will stall and yeast will die if the Co2 levels are too high in your FV. Yeast does not survive well in it's own byproduct. hope that helps.
-Ryan Power
Head Brewer
Geaghan Brother's Brewing Company
Bangor & Brewer, MAINE
Comment: Mash temp plays a small role, biut grist is a much bigger player.


Scratches on brake lever

Question: I recently had a crash and gained a few scratches on my brake lever (see photo)
How can I remove these scratches  as they look bad and I can feel on my fingers when I ride.
Thanks
Comment: "there is no problem so bad you can't make it worse."
Comment: Go easy on the sandpaper.  Just enough to remove any unpleasant sensations for your hand.
Comment: That's very normal and harmless wear. They usually look much worse after some time simply from leaning against walls. Find sandpaper is probably enough to smooth the worst burs.
Comment: I guess that's "fine" sandpaper
Answer: Hard to tell exactly how deep they are from the photo, but they don't look too bad.  I would take the bike to a store that sells cosmetics and pick up the 2-3 shades of nail polish that look the closest match.
Once you get home, sand off any rough edges with some very fine sandpaper and mix nail polish to get the colour you want before finally painting over the scratches.
Answer: You can first sand or file off anything that's protruding from the handle, then use sandpaper to get any major roughness off. You probably only need to start off with 220 grit for a few seconds, then go to finer and finer grit. Your local hardware or home improvement stores will have a variety to choose from. Likely, you don't need to go further than 1000 or 200 grit.
After that, if it's smooth to the touch but not to the eye, you can use buffing compounds and a buffing wheel to smooth it out further. (That is, if you have a drill or rotary tool, like a Dremel). This is if it's actually metal, like the aluminum (or possibly stainless steel) it looks like from the pic. Just make sure the polishing compound and wheel is designed for the material you are using it on and of a high enough grit count that you don't scratch the handle further.
If the handle isn't metal, it's steel but not stainless, or you just can't get it smooth enough for your desires, you can paint it. You can try color matching or just change the color to suit your desires. Or if it's bare steel, you can put on just a clearcoat to prevent rusting. However, if it's stainless steel, you probably don't need to do that.

Scratches on brake lever


Does repolarization of muscle fibers mean that the muscle bundle is relaxed?

Question: If I flex my bicep and continue to contract it does it mean that the muscle cells are in depolarizing state and not repolarizing?
Answer: No, macroscopically human muscle works by oscillation. This means that when a muscle is contracted (isometric contraction), some fibers alternatively contract through the actin/myosin process while some others relax at the same time. The end result is that the muscle as a whole keeps the same length, although it still does consume energy to stay in that state. That is why you get tired after some time of isometric contraction. To directly answer your question, it means that muscle in isometric contraction state will have some fibers depolarized, and others in resting state at any moment.


Is there a way to store drywall vertically on its side?

Question: I am going to have a surplus of 8 sheets of 5/8" 4x8 drywall (4 type-x, 4 QuietRock 525) until my next soundproofing job this Summer.  I have been storing 8 sheets at a time stacked flat on my upstairs guest room floor, but I don't want to store the remainder up there until Summer.  If I could store it vertically up against the wall wrapped in plastic in my garage, that'd be great.  Any ideas on this?
Comment: Any chance you'd be willing to share your project with the class as a blog post?  A couple before and after pictures, some links to the various questions you've asked along the way, and some things you've learned throughout the project would make a great post.
Comment: You could always make it an ongoing series, instead of a single huge post.  You could break it down in to sections (demo, preparation/planning, installation, finish, etc...).
Comment: It's going to be a few more months before it's done, but I have lots of pictures and experience to share.  Next on my list is apply drywall to the ceiling. After that, fix up the floor with probably MLV, Green Glue, and Homasote.  Finally, soundproof the doors.  If it all proves effective, I'll post a very long and well-written account of my experiences.
Answer: You could build a drywall storage rack.

Start by building 2 or 3 triangular frames out of scrap 2x4s.

Space them out to the desired length.

To prevent sheets from sagging between supports, lay a sheet of plywood on the rack before placing drywall on it.

A rack like this may be overkill for a short term storage solution, but could come in handy if you find yourself storing drywall for extended periods. It's nice because you can store the drywall in less space, it keeps the drywall off the ground/floor, and it prevents the drywall from warping.
Comment: I ended up going sorta this route.  I didn't have spare 2x4s, but I did have plywood.  I leaned them up against the wall at an angle and then leaned the drywall on those.  QuietRock 525 has heavy backer board on the back, so I put that up first.  After four sheets of that, my remaining sheets of type-x were well supported.  Thanks for your answer, too, BMitch.  I upvoted it.
Answer: It's stored on it's side (beveled edge up/down) all the time on job sites. Just make sure to protect bottom edge and keep it off the ground if there's a moisture risk. The best solution is to get 3 or 4 of the blocks of drywall that they have when delivering it (allows them to get the forklifts under a stack) and use those to keep it off the ground. In addition to avoiding moisture, the important part is to avoid tearing the paper and placing too much stress in one place or over too long of a span.
Comment: Make sure you strap it to the wall or something.  I know 1/2" will bow if it's just leaned against a wall for months.
Comment: I have some drywall waste that I can use to keep it off the ground.  It's 5/8" and is going to be there for several months (potentially Summer as I said previously), so it will definitely be okay so long as it's kept flat?  Also, what about the paper tearing?  Some of the drywall sheets' faces got scuffed during shipping and the outer layer of paper is torn away leaving the brown layer beneath (no drywall is showing).
Comment: @oscilatingcretin, the paper is half the strength of the drywall (plaster doesn't compress, but it offers no resistance to being pulled apart), so do your best to avoid damage.


Endogeneity in forecasting

Question: I know that omitted variable bias isn't a major problem in forecasting, but are other endogeneity issues (such as simultaneity or measurement error) going to be a problem if I am only interested in forecasting?
Answer: Its sure that endogeneity is not acceptable thing if our goal is to find structural/causal effect. You are focused on forecasting then endogeneity, as produced by omitted variables, actually don't is a major problem. Endogeneity produce, first of all, biased parameters estimates. Other sources of endogeneity as, measurement errors or simultaneity/reverse causation, produce biased parameters estimation as well.
However if your goal is forecasting (or contemporaneous prediction as well) your major problem is overfitting. This concept is related to loss function as mean square errors, that you have to minimize, and appear when we consider in sample vs out of sample measure.
Key concept for understand the crucial distinction in argument is bias-variance trade off. Read my explanation here (Are inconsistent estimators ever preferable?) and, mostly, the cited article to which it refers to.
For another explanation you can read this article
http://statisticalhorizons.com/prediction-vs-causation-in-regression-analysis
EDIT:
I embraced the distinction between causation and prediction in light of the arguments contained in Shmueli (2010), mainly based on the bias-variance tradeoff. The bias is not the core but it play a role in prediction also. Therefore the "theory" play its role in prediction as well. Then, the so called "data driven" (correlational driven) model can be seen as too extreme perspective even if our goal is pure prediction; the magnitude of bias matters. However this magnitude depends from the "true model" and in any real situation it is unknown; so the magnitude of bias. Fortunately this problem is only theoretical and, at least in my opinion, irrelevant. Indeed the relevant thing is that the bias-variance tradeoff give us a justification for see the regression in two markedly different way and, more important yet, give us a justification for develop very different metrics to adopt.
Infact the perspective about regression in causal inference and in predictive learning are markedly different. Moreover, also more relevant difference exist in the tools/metrics commonly used therein. If we do not accept a clear separation between causation and prediction those difference in regression practice are very hard to justify.
For example, models like ARMA and ANNet are "free of theory" by definition, they are purely correlational driven (data driven). The growing area of predictive learning, as a whole, follow the same perspective. Those models has demonstrate their effectiveness in practice and their superiority for forecasting purpose in comparison to structural models. While structural models is a necessity for causal inference. Latinus ancient people said in medio stat virtus; however, in my experience about causation vs prediction story, in the middle I see only confusion.
Comment: Note that biased parameter estimates can be optimal for prediction once the omitted variables have been omitted, because the forecast does not become biased; see ["T-consistency vs P-consistency"](https://stats.stackexchange.com/questions/265739/).
Comment: Thanks for the comment. I added something in order to clarify my perspective. I will go deeper on the topic you suggested later.

Endogeneity in forecasting


Automount flash drive lags

Question: I have 1GB flash drive and on Windows or other Linux machines it works fine. But when i push flash drive in my USB port on Ubuntu 13.04 3.8.0-29-generic, there is 1-3 minutes delay before automounting. Please help me to figure out why it is happening
Answer: I have the same issue with a usb2 pny 32gb ntfs formatted pendrive. Dropping back to kernel 3.8.0-27 solves the issue. I am running xubuntu 13.04 64 bit.
Seems to be fine with my usb2 kingston ntfs pendrives so maybe brand chipset related bug / issue with this kernel ??
Can someone confirm if this is a new bug ?
Answer: Upgrade to kernel 3.8.0-30 solve the problem

Automount flash drive lags


Limitation of Unemployment rate

Question: What is the rationale behind government not including discouraged workers who have given up looking for jobs out of frustration given the state of economy?
This under-reports the job market and at the outset looks ridiculous.
Comment: And which country are you speaking for?
Comment: @KentShikama: I think the question has broad validity. I don't know of any country that includes "able bodies" who haven't looked for work in a substantial amount of time in the usual unemployment figure. That's not to say it's not reported in another line. There's an ILO definition which limits the time span to 4 weeks.
Comment: As in why doesn't the default unemployment rate in the US include discouraged workers? U4 includes discouraged workers.
Answer: The U-3 unemployment rates is the total unemployed, as a percent of the civilian labor force (official unemployment rate). By definition it excludes the discouraged workers, which, as Varun and Kent understand, is not true of all unemployed statistics. I liked what Karabell (2014) says about this statistic:

...[T]here is nothing wrong per se with the [U-3] unemployment figure,
  provided you know that the definition of employment is a construct,
  not a counting exercise....to be unemployed, according to the
  Bureau of Labor Statistics, you have to be in the workforce. To be in
  the workforce, you have to have a job or be looking for a job. To be
  looking for a job, you have to answer when surveyed that you have
  actively sought employment at some point in the past four weeks. If
  you haven't, you aren't actually unemployed. You are a discouraged
  worker, are marginally attached to the workforce, and are not counted
  as part of said workforce. And if you haven't been looking for a year,
  you're not, statistically speaking, even discouraged. You simply,
  statistically speaking, don't exist. You do, of course, actually exist
  (though that is a whole other topic), but not in the statistical
  universe of employment data.
The result of such methods is that it is possible, and not just
  theoretically, for the unemployment rate to drop not because more jobs
  were created or more people were hired but simply because more people
  gave up looking for work and dropped out of the workforce. That is, in
  fact, What happened in the United States and swaths of Europe after
  2009, though in America, there were also real job gains in 2010 and
  after. Nonetheless, the unemployment rate, which receives so much
  public scrutiny, went down in part not because the economic system was
  creating so many new jobs but because it was failing to do just that.
  To be fair, the BLS keeps multiple unemployment statistics and
  different unemployment rates, including ones that include
  underemployed, marginally attached, and part-time workers, but there
  is only one headline number. That is what the BLS points to in its
  monthly release; that is what the media pick up; and the other numbers
  are at best footnotes.

The Leading Indicators: A SHort History of the Numbers That Rule Our World
Zachary Karabell (2014)
Therefore, if your question is why does U-3 exclude discouraged workers, the answer is that's an essential part of the definition of discouraged.
If your question is why did they define U-3 this way in the first place, I am not sure. I suspect the following. The definition of the labor force, which is workers and those actively looking for work or waiting to be recalled to work. Detached and marginally attached workers are not in the labor force. Once you defined the labor force, a natural question is what fraction of the labor force is not working, and that statistic is U-3.
If your question is why is this statistic more widely discussed than other economic statistics, the answer may simply be that it is older. The U-3 statistic goes back to 1948 while U-4, U-5, and U-6 start in 1994. People may be used to talking about the better established statistic and enjoy the longer time series, and see insufficient benefit to switching to the newer statistics, despite the benefits. A sort of Dvorak vs. Qwerty keyboard issue for economic statistics.
In a way, this is like an issue of GDP measurement. Home production is not in GDP and Robert Barro has argued that investment is double counted in GDP. If you want to use GDP as a measure of something else, these may be big problems and other measures may serve better. However, if you want to compare GDP across countries or time, these issues matter less than having something useful and consistent to compare them with. Commenter ABC at Marginal revolution has a nice quote about this:

The algebra is fine as it is, but I take strong issue with the idea
  that GDP "mismeasures" something. As any decent intro macro course
  will tells its students, "GDP is not a measure of welfare." Indeed,
  the Kuznets quotes that Barro points to are exactly of this nature; we
  have this high profile GDP number, but it doesn't do what you want it
  to do - or at least not ALL the things you want it to.
What Barro does here is construct a new measure - present discounted
  value of consumption - and shown how it relates to GDP (and GDP's
  present discounted value). In addition, he provides a capital income /
  labor income decomposition for both measures (GDP having such an exact
  decomposition because of constant returns to scale, Euler's identity
  for homogenous functions, and marginal-value input prices). He then
  says present discounted value of consumption, and its associated
  decompositions, are "right" while the other the construction GDP is
  "wrong" and thus gives "misstated" decompositions. Of course,
  "right/wrong" and "correct/incorrect" begs the question - right about
  WHAT? Correct for WHAT?
Barro says that in present discounted value terms GDP "double counts"
  investment. The "double counting" is only relative to how things are
  calculated for the present discounted value of consumption. This just
  reflects the fact that GDP counts production, while consumption only
  counts consumption.

ABC's comment on Marginal Revolution Post: Robert Barro says we double-count investment

Limitation of Unemployment rate


Views php field or filter to a file or module

Question: If I already have a view with a php filter or a php field, in drupal 7, how can I convert my whole view into a page? (prevent code injections or other security risks)
What is the right way to resolve this?
Writing a module or a tpl.php file?
Thanks
Answer: Found the answer here
Custom Views Field Handler
https://kalamuna.atlassian.net/wiki/display/KALA/Custom+Views+Field+Handler
Comment: While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference.  Link-only answers can become invalid if the linked page changes. - [From Review](/review/low-quality-posts/98354)
Comment: Well, i am still working on my solution.
Currently i have a php field in a view, and i want to use my own custom module with a view handler to delete that php field.
The link gives me some idea of what i need to do, but still no results.
Once i achieve what i want i'll write it here as a solution.


Use dynamic JSON page for Bubble Cloud d3.js

Question: I am creating bubble cloud using these sample codes in Github. https://github.com/vlandham/bubble_cloud
The codes are using .csv in data folder. But I want to create a page showing dynamic data. Now I have the link to the dynamic JSON page.
How to implement the codes to make the bubble cloud dynamic with the JSON page?
Answer: Are you just looking for somethign like the d3.json function? There are a bunch of request functions built into d3. Check here


How can I factory-restore a Samsung J5 (2015) SM-500FN?

Question: What I have:
I have a Samsung J5 (2015) SM-500FN which ran out of storage and basically hung itself up. There is no data I want to recover, but I want to install either a stock ROM or (preferably) something else like Lineage - I just want to get a usable phone again.
My problem:

I have tried to download many stock ROMs from reputable sources like SamMobile (for this specific phone, but trying different release dates and country codes) but every single one of those ZIPs is corrupt, even when downloading from a different computer.
Flashing with ODIN anyway gives a FAIL result and a device that cannot boot, not even into recovery: It gives a green screen with the text: An error has occurred while updating the device software. Use the Emergency recovery function in the Smart Switch PC software.
Ironically, the Smart Switch software just says this device is not supported. The older Kies3 software lets me enter the exact model# followed by the serial# - but then it says this device is not supported. So neither Samsung software is usable, but I can still use ODIN.
Even with the phone in this broken state, I can install TWRP again. So it is not completely bricked. I boot into TWRP and copy a LineageOS ZIP file to /sdcard, but when I try to install that, the TRWP console says: E3004: This package is for device j5nlte,j5nltexx; this device is . Note it doesn't appear to recognize that this device is indeed the model j5nlte!
Android.SE says that "E3004" means my TWRP is too old, but I use twrp-3.1.1-1-j5nlte which is currently the newest version for this phone.
I would also like to try a factory reset, but that requires the stock recovery which won't boot (see step 2 above).

My question:  How do I get out of this catch-22?
It seems that if I could just get around that E3004 then I would be fine. But I have found no ways to trick the installer into ignoring that error.
Answer: A friendly forum user pointed me to this updated version of TWRP which I could install using the already installed TWRP.
After upgrading the TWRP itself, I was then able to install the ROM I wanted. Problem solved!


Beginner on Rav Soloveitchik

Question: I am looking to delve into the teachings of Rav Joseph B. Soloveitchik (1903-1993). Any recommendations on a good starting point?
Comment: @intuit, Welcome to Judaism.SE, and thanks for bringing your question here! As the others have pointed out, your question will be more answerable if you specify it a bit more.
Answer: Although I personally have not read his works, I have a number of friends who were inspired by The Lonely Man of Faith.  Additionally, Halachic Man seems to be a must read.  Although chronologically Halachic preceded Lonely by a couple of decades, Lonely is more fundamental.
Comment: This is, of course, assuming that @intuit is interested in R' Soloveitchik's philosophical teachings. If, though, he is more interested in R' Soloveitchik's Talmudic methodology, this certainly would not be the place to start.
Comment: Also: Abraham's Journey is wonderful.
Comment: I am interested in his philosophical teachings.
Comment: I was privileged to attend a chabura on LMoF. It is awesome, but I needed the initiation in 20th-century theology, the background of the sefer, and RYBS's basic conceptual framework to really get the most out it.
Comment: *Halachic Man* seems to call for some grounding in philosophy, just FYI.  (I tried and failed; I hope to try again later.)  I haven't read *Lonely Man of Faith*.  I've heard good things about both of these.
Answer: I'm no scholar of the Rav, but I found the Rosh Hashannah and Yom Kippur Machzors and the Haggada based on his teachings to be eye-opening introductions to his oeuvre. They're full of references to his other published works, so if you see a passage you find particularly interesting, you can follow it up by studying the work it was excerpted from.
Answer: The Bergen County Beis Medrash has lots of Audio Shiurim from Rav Soloteitchik. That may be a good place to start.
There are also 164 of the Rav's shiurim available for download here. (linked to from here)
Answer: In my opinion the best place to start is Here:
The Rav Thinking Aloud on the Parsha
It is simpler then the other books that have some heavy philosophy and language. They are cross referenced to his other books so if you like an Idea you can find it and the person who wrote it was a close talmid. Plus it is on the Parsha so it makes it very usefull.If you want the Plain The Rav Thinking Aloud not on the Parsha it has most of his viewpoints on the important issues and it is an easy read
Comment: @DoubleAA do you have a source that the family made a request not to publish and the author went against that request? Or do you mean it was not authorized i.e. Post facto disapproval with the publication?
Comment: I'd have to recommend against this book, as it publishes conversations which were recorded without the permission of the Rav, and published against the explicit requests of all his living descendants.
Comment: @DoubleAA Rav Mordechai Willig; a close disciple of Rav Yoshe Ber, openly qoutes from the book
Comment: @Nafkamina I don't know why any of that matters.
Answer: I think the first one I read was קול דודי דופק, both very deep and very readable at the same time, a nice introduction to his way of writing, and philosophical methodology.
@YDK's suggestions of Man of Faith and Halachic Man are also good to go with.
Answer: I recommend two books in particular:
Aaron Rakeffet-Rothkoff, The Rav: The World of Rabbi Joseph B. Soloveitchik (2 vols; ed. Joseph Epstein; Ktav Publishing House, 1999);
Reuven Ziegler, Majesty and Humility: The Thought of Rabbi Joseph B. Soloveitchik (Urim Publications, 2012).
Answer: There is a 16-part audio web series from Web Yeshiva given on the Lonely Man of Faith taught by Rabbi Jeffrey Saks.
you can download it from here: http://www.yutorah.org/search/?s=lonely+man&series=4191
Give's a nice introduction to Rav Soloveitchik's teachings.
Answer: I strongly recommend Halakhic Man. (Some say to skip the first 40 pages. From what I have heard, people find them very tedious, as it is just a preface to the piece, and Rav Yoshe Ber uses very large words with which most people are unfamiliar, but after roughly the first 40 pages he actually gets to the premise of the essay.)
In it he describes and elaborates on the worldview and persona of the great halachists of the past. And how their approach and thought process differs from other personalities in their relation to G-d and the world he put us in.
Largely he sets down the philosophy of his family; the Soloveitchiks, and their approach to halacha and their mindset.
Answer: I know this is 12 years late but Ohr Publishing has been doing a fantastic job at subtitling the Rav's famous lectures. Here's the link to their YouTube page: https://www.youtube.com/@ohrpublishing-videosofravs1355

Beginner on Rav Soloveitchik


Is 85 minutes enough time to transfer in MCO from international flight?

Question: My international flight arrives in MCO (Orlando International) at 6:00 am. I must take another flight (MCO-JFK) at 7:25 am. Is that enough time to go through immigration, claim luggage and get to the boarding gate? I have already spent more than one hour in line for immigration at MCO, but I don't know if it is usual. If there is a long line, can I ask the officers to "skip" it?
Comment: Delta has four daily MCO-JFK flights, of which 7:29 is the first of the day. If you miss it, you won't likely be delayed for more than a few hours.
Comment: Specifying your nationality, type of visa/visa waiver/green card, and purpose of visit would be helpful in assessing the time to go through immigration, which is in most places notoriously longer for foreigners than for US passport holders. Also are you flying on the same airline, or airlines part of the same alliance? Are you ticketed through (single booking for both flights)?
Answer: I would say that you have a good probability to make it. Your flights are early in the morning so they are more likely to be on time and also the waiting time will be shorter in the checkpoints.
I would suggest you the following :
1/ Make yourself known by the company. If you have booked a complete itinerary with the same company, they will make what they can to make the connection happen as otherwise, they will be accountable to find a solution for you.
2/ If you see that the waiting queue is too long, check with the agents. Explain the situation with a smile and seek help from them. They will potentially direct you to the fast lane if any.
Good luck!


Why do we have an explicit rule of Safek Brachos Lehakel if we already have a greater encompassing rule of Safek D'Rabanan L'kulah?

Question: I understand that Safek brachos lehakel might simply be a corollary of Safek D'rabana L'kulah, however I assume there is some nafka minah between the two. The only reason we would have safek brachos lehakel is to teach us something that we may otherwise not have known had we only had the rule of Safek D'rabanan L'kulah. My question is: what hava amina might we have had if we only knew Safek D'rabanan L'kulah, that we needed Safek Brachos Lehakel to teach us otherwise?
Comment: That you shouldn't be machmir to say it?
Comment: If one thinks he said birchat hamazon and then is not sure, he has to repeat the deoreita part. It is a Brachah, but it is a deoreita.
Comment: Wasn't  this asked previously?
Comment: Good question, and welcome to mi yodeya!
Comment: @DoubleAA you mean Safek Bracha levatala or Safek Lo Tisa?
Answer: By brachos we have a couple different issues which need to be balanced. There's the obligation of making the right bracha before eating, the prohibition of eating without a bracha, and the prohibition of making a wrong bracha (using Hashem's name in vain.)
The gemara Brachos daf 12a discusses the case of a person who takes a cup of beer and mistakenly thinks that it's wine. He starts to make the bracha "baruch ata…" planning on concluding the bracha "borei pri hagefen", but after saying "haolam" realizes that it's beer and concludes "shehakol." (I'm avoiding the machlokes in the pshat gemara since it's not relevant for this question.)
Tosfos d.h. "lo" points out that the gemara doesn't clearly render a ruling in this case. He quotes the Rif ruling "leniently" that even in this case you fulfill your obligation. Then he quotes the Ri who rules "stringently" that you need to make the blessing again (i.e the stringency is that you did not fulfill your obligation.)
In the gilyon Hashas there R' Akiva Eiger brings the question of the Magen Avraham- how can you rule "lechumra" the general rule is "Safek Brachos Lekulah?
He answers the question by using the concept of the Maharsha in pesachim: we only say safek brachos lekulah regarding a safek birchas hamitzvah. Since we poskim that birkas hamitzvah is not meakev (meaning that even if you don't make the bracha before doing the mitzvah, you still fulfill your obligation of the mitzvah) therefore when in doubt don't make the bracha.
However, regarding birchos hanehenin (brachos before enjoying something like food) we have another rule: you're not allowed to eat without making a bracha (asur lehanos ba'olam hazeh bli bracha.) Therefore the Ri holds that you need to be machmir on that prohibition (of not eating without a bracha) and therefore make a new bracha.
(Rak"a says it's not a chashash bracha levatala since you can't eat without making the bracha.)
Rak"a on that spot refers to what he wrote on Tosfos daf 49b. There, the Ri says to be "machmir" and make a borei nefashos on a drink which is less than a kezayis.
Rak"a there asks- how can you be machmir, the rule is safek brachos lehakel?
Since on the bracha achrona there's no problem of eating without a prior bracha, we revert back to the general rule of safek brachos lekula.
From the machlokes between the rif and the ri (As explained by Rak"a) we see the rule of safek brachos lehakel isn't a simple ruling based on safek derabanan lehakel.
There's an additional aspect of safek brachos lehakel- when you don't know what the bracha is, you need to make the more general bracha.
i.e. if you're not sure if it's a fruit or a vegetable, make a ha'adama.
See here for a discussion of the sources.
When I make the ha'adama instead of the ha'etz, out of doubt, what is the leniency?
Here, the leniency is on making the proper bracha.
If the bracha should have been haetz, and I made ha'adama, I have been lenient regarding my chiyuv to make the better (more specific) bracha.
But I have to be lenient about that, since if I err the other way- I make haetz when it should have been ha'adama- I'm saying sheker and the bracha doesn't count. Thus it ends up that I'm not making any bracha, and I'm eating without a bracha!
Here, we see again that this discussion of safek brachos lehakel is not necessarily related to the question of safek derabanan lehakel.
When the gemara states (35a) that it's forbidden to eat without making a bracha first, it's not clear that it has the status of a torah prohibition.
But yet we see that we use the principle of safek brachos lehakel even when we're considering various rabbinic obligations and prohibitions.
[worthy of mentioning- Some poskim, including Rav Shternbuch in Shu"t teshuvos v'hanhagos (I think chelek beis) explain that the issur of benefiting without making a bracha doesn't require an actual halachic bracha. Thus, he rules that if a person isn't sure if he needs to make a bracha (maybe he already made a bracha, maybe he didn't) that he should think the bracha in his mind. While it doesn't fulfill the chiyuv of making a bracha, it does remove the issur of eating without one. Thus on the bracha itself we can revert to the regular rule of safek brachos lehakel.
This is again an example of how various aspects of hilchos brachos come together, and it's not enough to simply say safek derabanan lekulah.]
Comment: Remember most blessings aren't on food
Comment: @DoubleAA I agree. However, food examples are a great way of explaining why the two concepts aren't the same. As the OP suggested, there should be a hava amina why not to say safek brachos lehakel. By birchas hanehenim we have such a hava amina- the issur of eating without a bracha. (Rak"a's point.)
Answer: Penei Yehoshua to Berachot 12a writes:

הא דקיי"ל בעלמא ספיקא דרבנן לקולא לאו כלל גמור הוא דהא בכמה דוכתי פוסק הש"ס לחומרא אף בדרבנן היכי דאיכא טעמא
That which we rule in general that sefeika derabbanan lekula is not an absolute principle, as there are many places where the Talmud rules stringently even in a derabbanan, where there is reason to do so.

He goes on to note that there may be specific reasons why one would think to rule stringently in certain cases of doubtful berachot (and, in fact, Ri does rule that way).
Thus the principle of safek berachot lehakel could be telling us that we do indeed apply sefeika derabbanan lekula in cases of berachot.


Add a 5-10 minute delay before being able to answer a question

Question: As seen here, Stack Exchange has a problem where people are answering as quick as possible and putting minimal effort into their answers. To address this problem, I propose that there should be a 5-10 minute delay before being able to answer a question in order to give answerers enough time to write high-quality answers.
Comment: This doesn't make people write better answers.  It just means readers move on to another question.
Comment: Possible duplicate of [lock answering for questions for a short time](https://meta.stackexchange.com/questions/31863/lock-answering-for-questions-for-a-short-time)
Comment: @Devealte:  What does that have to do with the FGITW problem?  Those are meta-specific conventions.
Comment: @Makoto I'm talking about your comment: "If you downvote answers which are **poor and written in haste**"
Comment: @Devealte:   Yes, by convention I was referring to the main sites.  I'm really not sure why you chose to split hairs on this specific issue.
Comment: @rene:  The OP literally references that as a discussion point.  It's *not* a dupe.
Comment: Not such a great idea, people answer questions fast, then they edit it so it can become a high-quality answer. I do that sometimes and it works
Comment: If you downvote answers which are poor and written in haste, *most* of the time the answerer deletes them, thus negating any benefit for posting it in the first place.
Comment: @Makoto The tour page also says: "On posts tagged feature-request, voting can indicate agreement or disagreement with the proposed change rather than just the quality or usefulness of the post itself."
Comment: @Makoto Oh, sorry. I didn't understand that well.
Answer: Fastest Gun in the West is a problem, sure.
Locking out people from answering sounds like it can solve the low quality aspect, yes.  But, really, all it does is delay it by however long the lockout is.
Delaying answers doesn't increase quality; if users will post quality answers, they'll do it without the lockout.  If users can't post their answers instantly, one of two things will happen:

They'll wait until the lockout is done, and post then.
They'll discard their answer, and move on to a different question, where this will repeat.

Neither of those increase quality, nor does it account for the fact that some people are super fast typers, and can answer questions quickly, concisely, and well.
You can't force people to post quality answers.  You can encourage them to, by downvoting poor answers (which most instant answers are), pointing out issues, and basically just engaging in proper curation activities.
Downvote bad content.  If an answer, as it currently is, doesn't actually answer the question, flag or vote to delete it.  Vote to close if it's a problematic question.  If you feel up to it, comment on it to point out the problem.  Don't refrain from doing either of those if you think the poster hit the post button too soon; that's what edits are for, and you can retract votes after the fact.  There's no guarantee the poster will come back, and you shouldn't have to monitor a post.
Comment: No, it won't.  It might catch one or two here or there, but when people want to contribute, they'll find a way to do so, one way or another.  At best, this just delays the inevitable.  Curate the content.  Use your downvotes.  That'll do far more (both for future readers, and the system) to keep quality high.
Comment: I disagree.  Delaying answers does nothing to improve quality, it just moves the problem around.
Comment: The reason for all this is that the high-quality answers will not show up lower than the low-quality ones. They can all get upvoted at the same time, so the high-quality answers would rise to the top.
Comment: Which has literally nothing to do with locking people out.  People aren't going to race the lockout timer to type something better.  They'll either wait it out, or move on.  You can't force people to put in more effort.
Comment: It does. Temporarily locking a question will allow the high-quality answers to be posted *at the same time* as the low-quality answers. Otherwise, the low-quality answers would rise to the top just because they were posted first.
Comment: You're assuming that people would be racing the lockout timer.  Most good answers don't come instantly, but hours after the post.  Good answers naturally rise to the top.  They don't need to be posted quickly.
Comment: *Most* good answers. You only need one good answer. The whole point of this is to *reduce* the number of upvoted low-quality answers. There's no way to eliminate them, but this will help drastically reduce them.
Comment: The point is that not everyone *will* use their downvotes. Most people are not going to go through all the answers. They're usually just going to go through the first few. The low-quality ones will already have risen to the top, and the high-quality ones will be left sitting in the dust.
Comment: SE depends on the long tail to rise good content.  It won't happen instantly, but it will happen over time.  We're thinking long term here, not just the day or two after the question is posted.  Yeah, not everyone will use their downvotes.  That's *fine*.  But that's how you solve this.  With time, and working on keeping the signal to noise ratio as high as possible.
Comment: Not necessarily. As I said, many people only read the first few answers. They then upvote those few questions because they were answered first and are more easily visible. Because of that, the first answers will have lots of upvote that should have gone to the better answers. It's very unlikely that enough users will read through all the answers and upvote the best ones to bring them up to the top.
Comment: Late answers not getting enough love is a problem, true.  But that problem is *entirely* separate from the FGITW problem.  A ten minute delay does nothing to solve that.
Comment: No it isn't a totally separate thing. The first answers will get the most attention, just because they were answered first. That *is* closely related to the FGITW problem.
Comment: Delaying answers allows the bad and good to be seen at the exact same time. If nothing else, the good answers will rise to the top much quicker than they would otherwise.


Can you climb at Vxse when you cannot at Vyse in a multi-engine aircraft?

Question: Let's assume that you took off in a seminole and had one engine suddenly failed, say, at 400 feet AGL. You right away pitch for 88 knots (Vyse) to keep climbing, yet you start to descend because the density altitude is too high. In this situation, would pitching up for 82 knots (Vxse) give me a chance to climb back? Or would it only give me a greater descent rate?
Comment: Vyse is your best rate.  If you cannot climb at your best rate you cannot climb.  If Vyse gives you -100fpm, Vxse  will give you less than -100fpm (a faster descent).
Answer: I'd recommend reviewing Chart 5-23 from the PA-44 POH - Climb performance one engine operating - gear up for specific numbers based on aircraft weight and atmospherics.

If you're not seeing a positive rate of climb at your best rate of climb, single engine airspeed, then you're not going to see it at the best angle of climb airspeed single engine either.  By definition, Vyse is the best rate of climb that you're going to see on a single engine; any other airspeed, including Vxse, is going to give you a lower rate of climb, or greater rate of descent if a positive rate is not possible.  And attempting to acquire and hold Vxse you're getting close to the reverse side of the power curve, combined with ever decreasing rudder authority, it would be easy to have the aircraft drop below Vmc and depart from controlled flight.
Comment: Thank you for your answer. I posed the same question to my multi instructor lately and he told me in theory no airspeed would give you a climb if Vyse can't, but he added I should do whatever is necessary in emergencies and pitch for Vxse if it gives me a climb, which got me confused. Thanks.
Comment: Vx increases as the thrust margin reduces until it equals Vy at absolute ceiling (and then for gliding, Vx, as best glide angle speed, is higher then Vy). This works the same with both engines and single engine, just the values are different.


My PC doesn't recognize my galaxy note 4. But it did when I purchased it.

Question: My questions is just as titled.
When I got my new galaxy note 4 last month, I connected it to my PC and my PC showed my new note 4 so I was able to add video files.
But now  I connected my note 4 again to my PC to store all data from cell to PC cause it's full, my PC doesn't recognizes note 4. What should I do?
Comment: It might help if you could include some additional details: What Android version is running on the Note 4? Which OS are you using on your PC? Have you changed anything in the meantime (e.g. any updates made on the Note-4, or new installations on the PC)? Assuming you're using any version of Windows: Have you checked with your device-manager whether it shows any "conflicts" when the Note-4 is connected?
Comment: According to me the fix was to try different usb port
Comment: For me the solution was to use an **USB 2.0** port instead of a **3.0**. Sorry to put it here but I have not enough reputation to post an answer (though more than 7K on StackExchange!).
Answer: 2 options , both worked for Me when i had the Same issue:
If u use your fingerprintscanner , make sure you unlock your Phone After plugging it in
Second is to try Samsungs Software Kies and follow the programs instructions
Answer: Had the same issue with my Note 4. Tried out various techniques/solutions found online such as installing drivers, activating developer options, using code *#0808#, resetting to factory settings etc. None worked. I eventually put the phone into download mode to attempt to root it (by powering off then pressing the home key, volume down button and power button simultaneously). I then pressed the volume down key to cancel the operation and restart the phone (without rooting it). Connected to my computer and now it's recognized.
Comment: I have the same problem but putting it in download mode and cancel did not help me. Neither the *#0808# settings.
Answer: I tried the download mode thing and that didn't work. I was using some random micro usb cord that I had laying around. I decided to try the factory cord and my computer immediately recognized the phone was plugged into it and I was able to access everything on the device.
Answer: I also tried a different micro usb cable and that fixed my issue.
Answer: So I couldn't get my Note 4 or Galaxy Tab3 recognized by my computer recently.
The real crazy answer is that it had to do with my USB PORTS!  I had too many devices hooked up to the USB ports on my computer and there wasn't enough juice to communicate!  Once I disconnected a bunch of devices and tried various ports again, it worked!  It must not have been getting a full 5V I'm guessing?
As long as you are in the right mode and USING the RIGHT USB PORT, it should work!

If you have a Note 4, Dial <code>*#0808#</code> and make sure you are in "MTP + ADB Mode" and hit OK.  For a Galaxy Tab3, you need to hookup to a Windows 7 machine and then when you see the USB connection on the phone, bring down the top menu and select it and then make sure the phone is in "MTP mode" and not "PTP mode".
Using a known working USB data transfer cable (be aware that some cables only charge and don't transfer data), connect it to the phone and then keep trying DIFFERENT USB ports on your system until at least ONE of them works!  And if all of them fail, start DISCONNECTING your other USB devices from nearby ports and try again.  If even that doesn't solve the issue, try a POWERED USB HUB.

And if all of this fails to work, then you need to test your cable and eliminate it and finally in the last case scenario, you might be the unlucky one who has a damaged or defective phone micro usb port which only charges but doesn't communicate with a PC!  This has happened on one of my Galaxy S devices so it is possible but unlikely.
This will drive you nuts and cost you a lot of time unless you know this.  I hope this helps someone!
Comment: Typing *#0808# and enabling MTP + USB did it. That's totally stupid though, it should just be a setting in Settings, not some hidden code. Weird. Sanmsung, don't do that again, hiding useful features.
Answer: I just waited there for a little long while, and eventually Windows started recognizing the phone. (After a couple of minutes of being plugged in.)
In the beginning the phone appeared to have no contents, but that was only because the phone was waiting for a confirmation from me as to whether I wanted to allow the PC to access the contents of the phone or not.  Once I agreed, the phone was not only recognized, but its contents were also accessible.
Answer: If you connect the Samsung Galaxy Note 4 to your PC via USB, then it may happen that the device is not recognized as a media device. Thus it cannot be accessed the internal memory to copy images, music or videos. The Samsung Galaxy Note 4 isis only recognized by the PC as a camera module. If this situation applies with you, then we want to explain to you in this manual, how the Samsung Galaxy Note 4 is recognized correctly as a Media Device from your PC.
For this purpose, the "USB debugging" option must be activated, which is located in the developer options of your Samsung Galaxy Note 4. If you do not already have unlocked the developer options on your Samsung Galaxy Note 4, then please follow these instructions.
After the developer options are enabled on your smartphone, you can now tap the button "Developer Options" in the settings. You will get a list of different settings. In the section "Debugging" you will now find the "USB debugging" option. Set a tick in the checkbox to enable this feature on your Samsung Galaxy Note 4. If it is already enabled, disable and re-enable it with the data cable connected to the pc.
This mode starts automatically once if your smartphone is connected to the computer via USB cable and is responsible for that the Samsung Galaxy Note 4 is recognized as a media device by your computer. You can now access the internal memory of your smartphone and copy music, videos, photos etc.
You know now how to enable USB Debugging on the Samsung Galaxy Note 4, which makes it possible to detect as a media device.
Comment: please improve formatting


why they use crystal frequency three times the required CPU clock?

Question: In the data sheets for 8284a, the said The crystal frequency should be selected at three times the required CPU clock.
why they use crystal frequency three times the required CPU clock?
Answer: The 8284a has a divide by 3 counter, to generate a clock with 33% duty cycle which is required to run the 8086.
source
Answer: To supplement C_Elegans' answer:
The 8086 requires a 33% duty cycle clock, instead of a 50% duty cycle clock, in order to optimize the internal combinatorial logic timing and to also synchronize with peripherals attached externally to the 8086.
The 8284A clock generator was included as an additional IC to make it easier on designers, by providing the required 33% duty cycle clock and some reset and bus logic functions. To keep things easier for the 8284A, the designers simply applied a divide-by-3 function in order to generate the 33% duty cycle. There are other ways of achieving this in more modern parts today, perhaps. And perhaps, if something like this were needed today, it might be handled in a less externally visible fashion. But at the time, this was the most obvious and easy path to get there.


Why would a blind creature evolve display features?

Question: I'm thinking of a predatory creature that lives deep inside large caves. Because this environment is so dark, the creature's eyes have disappeared through evolution since the creature relies on echolocation rather than sight. But the thing is that this creature has a large frill around its neck with small bioluminescent marks. But that got me thinking, what is its use? I mean, if the creature is blind then it surely can't use the frill to frighten other members of its species. So why would it evolve something like that?
Comment: Welcome to Worldbuilding, Johnara! Cool first question. If you've got a sec, feel free to take the [tour] and check out the [help]. Have fun!
Answer: Just think of that other place where the sun doesn't shine. I mean the ocean depths.
The bioluminescence of a blind animal (such as a bioluminescent jellyfish) can either stun or confuse a predator that is not blind.
The atolla jellyfish in particular is a sore loser - if it gets attacked by a predator that is able to eat it, it gets flashy and its lights end up attracting even bigger predators that will eat its attacker.
And the there are the angler fish. They use bioluminescence to attract prey. Granted, they are not blind. But your blind creature may use its frills to both attract and capture prey.
Answer: The bioluminescence can be a vestige of when the creature's ancestors lived in very dim caves or caves (or other spaces) that were dark part of the time while they were awake.  While they still had functional eyesight.
Plenty of species have biological traits that aren't currently needed.  If there's no evolutionary advantage to not having them, they may not fade away as quickly as traits that are better off not being there (like eyes that can be a vector for infection if injured).
Once you've established that the bioluminescence is still around, it can prove itself useful in the ways other answerers have mentioned.
Answer: The chemicals that create bioluminescence in animals are often highly toxic.  This could be a warning to predators, which is how it is often used in nature for terrestrial creatures, or a part of its hunting strategy.  If the frill is spikey, like the quills of a porcupine, it could use them to poison and kill its prey.  Obviously, the creature itself would be immune to this toxicity.  This would have the added bonus of being a sort of area-of-attack weapon, which might be good for a blind creature.
Answer: Not all animals who live in the cave or who live nearby may not be completely blind like your creature. Maybe there are others who use very acute vision, who could see well with tiny amount of light. Or maybe they have their own sources of light, like the Angler fish which helps them see inside the dark caves.
So while your creature is visually blind, it may still help it to have a intimidating frill to frighten off predators, and it can evolve while the creature itself is blind.
Answer:
So why would it evolve something like that?

Because it evolved the frill before it became a completely subterranean species.
Additional thoughts/uses:

The frill is an echolocation receiver (it helps capture the reflected sound waves).
It's a mating display, possibly with the bio-luminescent spots "looking" different to echolocation than the surrounding frill (the spots served as display while the species was sighted, and developed to remain a display while the creatures lost their sight)
Appearing larger than they are (anti-cannibalism: small creatures look larger from head-on, so larger members of the species don't try to eat them)


Why did scientists find fractional particles in the experiment of particle collision?

Question:
Quarks can't be isolated because of the quark confinement. Then why did physics observe particles with fractional charge coming out in the experiment of deep inelastic scattering?
Gluons are the force carrier of the colour force. We found gluons  because there was a third jet appeared in the collision of an electron and a positron, but how can we know that was a gluon? Why was that a gluon?
The physicist came up with the idea of gluons after or before this experiment? If it was before, how did they came up with it? Wasn't that hadrons need to be colour neutral so that  they attract each other specific enough to explain why they combined each other tightly together?
How can gluons interact with each other? Gluons are massless, are they pure energy?
Comment: 3. Is a photon pure energy?
Answer: It's important to understand that we don't directly observe quarks and gluons in scattering experiments. What we observe is an unruly shower of well known and understood particles hitting our detectors. To try and understand what happens in the collision we use a mathematical model called the Standard Model. That is, we have equations that describe how quarks and gluons behave, together with parameters such as their masses and interaction strengths, and we use this model to calculate the expected scattering products. If we find that by adjusting the parameters of our model we get a good fit to the data this is evidence (but not proof) that our model is correct.
And we find that the results from our collider experiments are consistent with our model of quarks with fractional charges and massless gluons. Indeed, we have many decades of such experimental results, all of which are consistent with our quark/gluon model, so few physicists doubt that the model is basically correct. That's why you'll see statements like the up quark mass is $2.2$ MeV and the charge $+\tfrac23$. Strictly speaking these results have not been absolutely proven but in practice no-one doubts them.
Now to get to your specific questions:

We have never observed particles with fractional charge coming out in the experiment of deep inelastic scattering. We have observed boring old electrons, muons and pions coming out of the deep inelastic scattering experiments and inferred from these that quarks with fractional charges are present, even though confinement ensures we will never see an isolated example.
As above we cannot ever see an isolated gluon but the scattering products we can see imply that gluons exist and have the properties attributed to them.
Massless particles can interact quite happily. For example, massless photons interact with electrons. Indeed, above the electroweak transition we believe all the elementary particles are massless. Mass is not the fundamental property many believe. Instead it arises from interactions of the elementary particles with the Higgs field.

I should finish by saying that our quark/gluon model is quite possibly an effective model, i.e. a model that works well only as long as the interaction energies don't get too large. If String Theory is correct then neither quarks nor gluons are fundamental but instead are low energy approximations to string states. You'll see lots and lots of speculation about this but there is currently no experimental evidence to confirm or deny it.
Comment: Slight caveat, only *elementary* particles are massless above the electroweak scale, bound states such as the proton and neutron would still be massive I think.
Comment: @KFGauss good point. Thanks :-)
Comment: @First, I appreciate that you spent time answering my questions and the deep inelastic scattering seems to make much more sense. But I am still confused about the second question asked--you said that we didn't directly observe quarks and gluons, they are just the facts that can be explained by the Standard Model-- but how can the third jet came out from the collision be explained by the existence of gluons? Why were gluons(we suggested they are the sources of the strong nuclear force)emitted during the annihilations of positrons and electrons(which are leptons that even can't feel the force)?
Comment: @EZhang an electron or positron cannot directly couple to a gluon, but they can couple to any charged particles including quarks. So in a high energy electron-positron charge mediated interactions can create quarks and those quarks can then create gluons via a color mediated interaction. That is why gluons can appear in an electron-positron collision.
Comment: Yeah, the positron and the electron annihilate and create two gamma photons which have too much energy and soon materialise into a quark-antiquark pair and the pair release the excess energy in forms of gluons. That can be explained by the Standard model. Thanks.


What will the ERC20 converter use as an exchange rate?

Question: Will it convert tokens based on ADA/ETH pair price at the moment of conversion? If so, which exchange will it use for knowing the rate of exchange?
Comment: For one thing, the ERC-20 could be an escape valve from the high gas fees on the Ethereum network if similar smart contracts on Cardano cost less to use.
Comment: Are you sure the ERC-20 converter can be used to swap tokens? My understanding is that it can be used to move the same token between the Ethereum network and the Cardano network.
Comment: I'm not sure, I only assumed. Good point. But then how would an ERC20 token benefit from the Cardano network advantages? This would give rise to many other questions.
Answer: I assume that a good solution would be to provide an oracle that calculates the average price coming from different exchanges.
Comment: Sounds like a great idea to me. Practical and appropriate Oracle application indeed. Though it would mean that the converter cannot function until it gets data feed from an Oracle first.


Why did Barry Lyndon intentionally shoot to the ground?

Question: In the end of Stanley Kubrick's 1975 film Barry Lyndon, the protagonist is in duel with his stepson, whom he hates. When Barry has a very good chance of killing his opponent, however he intentionally fires to the ground. Why would he do that?
Comment: Possibly Barry Lyndon, for all his flaws, is not capable of cold blooded or hot blooded murder and would rather take his chances of being killed than kill even his enemy.
Answer: As explained here:

Culturally, taking turns displays an even more amplified absurdity of
  high society than we've had so far. Stand still while someone shoots
  at you. It's likely that the coin flip itself could seal your fate.
  And here is the theme of the film. A lot of chance occurrences led
  Barry to becoming a gentleman and to this duel and the duel itself
  represents both fate and the absurdity of civilized society. You can
  make shooting at each other appear gentlemanly, but violence is
  violence.

Of course, the scene goes deeper than that:

Each of the three moments of gunfire represents a turn in the scene.
  Bullingdon's first shot, a misfire, represents an act of fate. He
  might very well be killed because of a simple mistake. It is
  interesting that, while building tension, there is a surprise moment.

This surprise allows for this pivotal moment:

However, despite all of the coincidental events and choices that that
  led Barry down a variety of unknown paths and to this very situation,
  he seems to have finally received a concrete choice to which he knows
  the outcome: kill Lord Bullingdon and rid himself of an annoying
  adversary or spare his life and attempt to heal their relationship and
  his reputation. Barry chooses the latter and fires his pistol into the
  ground. Perhaps, Barry was now fully assuming the role of an honorable
  gentleman.

This duel also fits with the other duels in the movie:

JB: Barry Lyndon is punctuated by no less than three duels: the one
  that opens the film, in which Barry's father is killed; the one that
  sends Barry on the lam, in which Barry appears to kill Captain Quin;
  and the one near the end of the film, in which Barry and Lord
  Bullingdon seem determined not to kill one another. Each scene has a
  slightly different mood—from swift and deadly to drawn out and
  inconsequential (relatively speaking)—but each scene highlights the
  absurdities of dueling, and thus the foolishness of any people who
  would partake in the ritual.
[...]
EH: The duels are indeed one of the primary vehicles for Kubrick's
  satire of the "noble" class and their silly, artificial rules for
  living. As you say, the film opens with a duel, which immediately
  establishes the absurdity of staking one's life over minor slights of
  "honor," so that a life is erased in mere seconds. This absurdity
  calls into question the whole concept of honor as it's understood by
  the society depicted in this film — duels as presented by Kubrick are
  not so much showcases for honor and nobility but evidence of fragile
  egos forced by convention to respond to even the slightest of imagined
  insults.

The article also puts the final duel into a larger context:

JB: By the time Barry enters into that final duel, he's seemingly lost
  everything. We've seen him shunned from his old social circle. We've
  watched his son die. And then, in the duel with his stepson, Barry is
  shot by Lord Bullingdon even after he spares his stepson by
  intentionally firing into the ground. Barry's sacrificed shot seems
  less a matter of etiquette (you wasted a shot, so I will) and more
  like an olive branch, an admission of guilt, an act of atonement.
  Barry knows that he has treated his stepson poorly, so he understands
  Lord Bullingdon's rage, much like Captain Quin must have understood
  Barry's rage all those years ago. There's a sense when Barry fires his
  shot into the ground that he hopes Lord Bullingdon will shoot him dead
  and end his misery, but when Lord Bullingdon announces that he has not
  received "satisfaction" there's a subtle expression of surprise that
  flashes across Barry's face, as if the last thing he imagined is that
  Lord Bullingdon would continue with the duel after Barry spared him.
Of course, Barry's ultimate fate in the duel is the worst thing he can
  imagine. He isn't spared. He isn't killed. He's maimed, blasted in the
  leg. In the next scene, the doctor examines Barry's leg and says he'll
  have to amputate. "Lose the leg? What for?" Barry asks. "The simple
  answer to that is 'to save your life,'" the doctor replies. This, it
  turns out, is the low point for Barry. Suddenly it registers for him
  that there's no coming back from this duel, the way he'd reinvented
  himself all those years ago. He'll forever be crippled, and he'll
  forever have a physical reminder of his sins. And as Barry comes to
  this realization, weeping in bed, a church bell tolls in the
  background.
Answer: Possibly Barry Lyndon, for all his flaws, is not capable of cold blooded or hot blooded murder and would rather take his chances of being killed than kill even his enemy.
I note that BCdotWEb's answer quotes this from an unspecified source:

Culturally, taking turns displays an even more amplified absurdity of high society than we've had so far. Stand still while someone shoots at you. It's likely that the coin flip itself could seal your fate.

But it seems to me that standing still while someone shoots at you might not be good for your health, but is an act of self control that has often been chosen voluntarily, and has often been legally enforced on people.
Barry runs away from Ireland and enlists in the British Army, fighting in the Seven Years War (called the French and Indian War in the USA) and later fights in the Prussian Army in the same war.
As an enlisted man, Barry was required to shoot when ordered to shoot, and to not shoot when not ordered to shoot.  Among other things, that meant that he could have been severely punished for shooting in battle if not ordered to do so.
For over two hundred years European armies fought in close ranks, the men of each battalion marching together into position and standing up and shooting at the enemy all together, in volleys.  Volley fire had a much more demoralizing effect on the enemy that shooting at will did.
In those days the muskets had to be reloaded after every shot, which took time.  After firing a volley, a unit was incapable of harming the enemy until they reloaded.  As two units marched closer and closer and closer together the men in each unit knew that the probability that the other side would shoot at them was getting higher every second.  Every second the tension and the temptation to shoot got stronger and stronger.
Muskets were not very accurate.  Many armies didn't use the command to aim when shooting.  Instead the command was to level the muskets.  Since the two tightly packed units would be facing each other, there wasn't much need to aim the muskets right or left in the horizontal direction.  It was hoped that if the muskets were level they wouldn't overshoot or undershoot the enemy.
And the closer to the enemy when the volley was fired, the greater the proportion of musket balls that would hit enemy soldiers and contribute toward winning the battle.  If a unit fired too soon to do serious damage to the enemy, the enemy might blast them with a more damaging volley before they could reload and fire again.
Thus many battles in that era began as giant deadly games of chicken, the officers on each side hoping the other side would fire first while still too far away to do serious damage.  There were battles where an officer of one side politely ivited for the other side to shoot first and an officer of the other side politely declined.
Thus privates like Barry Lyndon were often ordered to stand and do nothing while the enemy shot at them, until the officers ordered them to shoot back.  A soldier who shot back in battle without being ordered to could be punished for disobeying orders.
And in those days officers rarely used guns and rarely shot at the enemy.  Instead they led, commanded, directed, and encouraged their men.  Barry would have often seen his officers leading under fire without shooting at the enemy.  He knew that was expected of an officer and a gentleman, and Barry spent most of his life trying to become accepted as a gentleman.
The non commissioned officers also usually led instead of shooting.  And Barry may have known privates who hoped to become non commissioned officers.
And then there were the musicians, the drummers and fifers, whose job was to sound various signals in battle, and to beat the time as the men marched to help them stay in step. Their job description had no place for shooting at the enemy while they were being shot at.
You may note that at that time officers often began their careers as teenagers, and sometimes younger.  And you may have heard of drummer boys, teenage and younger boys who served as military drummers.  It is certainly possible that a real private in Barry Lyndon's units at that time could have seen boy officers and drummer boys younger than himself, who did their jobs in battle under fire without either running away in fear or shooting at the enemy.
Thus in the era of Barry Lyndon there were at any one time hundreds of thousands of men, and possibly thousands of children, whose jobs required them at times to be shot at without either running away or shooting back.
How did soldiers in that era deal with feelings of guilt for taking part in such bloody slaughters?  No doubt to many it was no big deal to kill enemies of their country in battles sanctioned by their government.  But many others no doubt felt a lot of guilt for taking part in mass slaughters
The privates - and Barry Lyndon was a private for a few years - could explain away their part, since they almost never aimed at individual enemies and the smoke from a volley would make it impossible for them to see if they hit anyone.  Furthermore, the privates were drilled to perform like automations on the battlefield without any initiative, and could claim that they had no choice but to obey like robots orders to fire.  If a private shot without orders, and/or aimed at a specific individual person, he would not be able to make that excuse to justify his actions.
The officers, who were mostly gentlemen - the social class that Barry Lyndon spent much of his lifetime becoming a part of - could deny their guilt for the carnage of battle by claiming that they didn't (or very rarely) personally killed anyone (and if so, almost never with a lower class weapon like a musket).  They could claim that instead of killing people they directed and ordered the actions of the privates, who were the ones who fired the guns and actually killed the enemies.
The role of a gentleman officer in battle was basically to risk his life in constant danger directing and inspiring his subordinates, without personally killing enemies.
And over time the gentleman's code for duels came to frown more and more on trying to kill the opponent, and more and more to favor showing the duelist's bravery, his willingness to face possible death for his honor.
Over time, gentlemen became more and more convinced that killing people to avenge insults was not ethically justified and was murder, just as the law said.  But they were too afraid of being considered cowards by declining challenges to duels.  So it became more and more common for gentlemen to decline to shoot, or to shoot into the air or the ground, during duels, showing that they were brave enough to face death in duels, but not savage enough to kill someone in duels.
Thus over time the probability of being killed or seriously injured in a duel got lower and lower.
That was not as good a situation as dueling being abandoned totally by all gentlemen, but it was an great improvement over the time when both parties in a duel would probably intend to kill the opponent.
So from an ethical point of view I do not see the sense of criticizing someone for not shooting at his opponent in a duel or asking why he doesn't shoot at his opponent.  That is asking why someone is not evil enough to attempt murder of, in this case, a relative by marriage.  And even the most evil persons in history did have some ethical standards; even men who slaughtered millions of innocent victims drew the line somewhere and would not have killed some persons under some circumstances.


How to show a Views attachment in other region or create a block acting as attachment?

Question: I have a view with two displays: page and attachment. The exposed filters are the same for both the displays, and I used the Inherit exposed filters in the attachment settings.
I want to put the attachment in a specific theme region. How can I print the attachment in a different region?

The "pink" box is the attachment, which contains a Leaflet map. The user can select either one of the filters and see the results in the box map and the page below (node1, node2, node3, ...).
This is a screenshot of the view page as it is now.

Either of these solutions could work for me:

Be able to display the attachment display in another region, then the
page display under it
Have a block that functions in the same way as an attachment and
inherits all exposed and contextual filters in the way an attachment
would do

I tried to use views_embed_view() in a custom PHP block. The block shows correctly the attachment, but the filter doesn't work with the new block.
$view_name = 'indoor';
$display_id = 'attachment_1';
print views_embed_view($view_name, $display_id);

I think the problem is the AJAX parameter view_dom_id passed to the block.
This is what i want:
Answer: At moment I fixed with contextual filter query by disabling the ajax and get query from URL. This way I can use separated block for the map.


Is it possible to bind dynamic texture samplers to a shader in DX12?

Question: So usually texture samplers are set directly in the D3D12_ROOT_SIGNATURE_DESC structure in DX12, at least that's how I've been setting them. I was wondering if it's possible to put them in an upload_heap and map a CPU pointer to it or something similar to make it possible to modify the samplers dynamicaly?
Answer: Yes it is possible by putting Samplers in descriptor tables to dynamically assign and index into them. Source: https://youtu.be/Wbnw87tYqVg?t=754
Here's an example that uses the HLSL root signature syntax to do this here:
https://youtu.be/Wbnw87tYqVg?t=5277
Comment: Can you put the examples in the answer itself, rather than as video links?


Can a Magic Circle Against Evil protect a creature from a Night Hag's Dream Haunting?

Question: Can a Magic Circle Against Evil block the night hag's Dream Haunting (Su)? The dream haunting has the flavor of "exercising mental control over the creature," but the dream haunting description only seems to rely upon the night hag hovering over the creature.
Answer: No, it will not protect the recipient of the Magic Circle against Evil.
The Magic Circle only does three things, none of which impede the Night Hag:

Prevents summoned creatures from entering the area. The Night Hag isn't a summoned creature.
Prevents domination-type mental control over the target's actions. The Dream Haunting doesn't exert any kind of control, let alone metal control of physical actions.
Grants a bonus to AC and saving throws against attacks or effects from any evil creature. Unfortunately, Dream Haunting doesn't grant a saving throw so the bonus doesn't come into play.

So the Night Hag can ethereally enter the Circle just fine, can hang about and trouble the victim's dreams so that they lose CON in the morning, and can do that without granting a saving throw. If the victim somehow did get a saving throw (perhaps from a magic item that gave saving throws against things like this regardless of whether they normally get one), only then would the Circle have any effect, and then only a +2 to the save.
Comment: Protection from evil does ward against mental control *other* than "*domination*-type".  But the night hag's ability isn't any type of mental control.
Comment: The wording on *protection from evil* is a bit ambiguous on the point of what, exactly, constitutes mental control: *dominate* clearly counts, but does *charm*? Hard to say. Enchantment (Charm) effects are explicitly included, but *charm* isn't **really** the same as "control"...
Comment: Oh, also -- regardless of the title, the question was only about the second point.  Discussing the first and third uses of the spell is probably not necessary.
Comment: @starwed Probably not necessary, but it does provide a full-spectrum "this is everything it does, and none fit" to the intuition that a circle that protects against evil *sounds* like it should stop the night hag's dream haunting.
Answer: No, because that is not ongoing mental control.  Protection from evil states that

the barrier blocks any attempt to possess the warded creature (by a magic jar attack, for example) or to exercise mental control over the creature

It does not ward against any mental attack, just those that result in mental control.  The dream ability is simply an attack against the creature through their dreams; it doesn't let the hag tell the creature what to do, and therefore protection from evil will not help you here.
Comment: Doesn't the "or to exercise mental control" exactly *match* the supernatural ability's description and thereby include it in what the circle prevents? Does it really matter whether it's brief or ongoing?
Comment: @Zachiel Yes, I see what you mean. Though a close reading gives me an answer from a different angle...
Comment: @SevenSidedDie AFAIK "to exercise *mental* control" does not mean "to control his mind" but "to control his actions with my mind". I don't think the duration is relevant.
Answer: Dream Haunting is not "controlling" the targeted creature, thus it's not blocked by protection against evil and similar spells.
Comment: *protection from evil* does not specify that it only works on [mind-affecting] effects.
Comment: You're right, I've been foiled by a player for years. Fixed.


How much press strength for human flag?

Question: Shoulder strength seems to be the main factor for achieving a human flag. I was wondering if there is some number relative to the bodyweight that indicates when one's press strength is ready to try a human flag. E.g. you should start training the human flag on a bar when you can move 0.7 times your bodyweight in a standing press. Or even: You need at least 0.8 to do a human flag.
Comment: Nice question, but I'm not sure you're going to find a number anywhere. Plus, there's a skill component involved. Also note that a flag is a push/pull movement, as the upper arm will be pulling.
Comment: Found a comment by Jim from Beast Skills: "If you can do several full range handstand pushups against the wall, then you're well on your way to getting the flag." [source](http://www.beastskills.com/the-flag/)
Comment: Thanks, that's quite alot. A full range HSPU is nearly like pushing a bar with your entire bodyweight upwards from your chest. According to strength standards this is somewhere between advanced and elite level, which is like crazy strong, and will require a few years: http://www.exrx.net/Testing/WeightLifting/PressStandardsKg.html
Comment: Well you are holding a significant amount of your bodyweight with the pressing arm in a disadvantaged body position, so it's to be expected. I'll try to investigate a bit more and post a full answer.
Answer: Jim Bathurst, known for his web site Beast Skills, says in his human flag tutorial:

If you can do several full range handstand pushups against the wall, then you're well on your way to getting the flag.

Overcoming Gravity, a popular book on gymnastic training for adults, has a chart comparing the difficulty of various skills. In the chart, a full human flag is a level 8 skill, which is "equivalent" to a press of your bodyweight, or weighted dips with 85% bodyweight added. The first progression to a flag, the tuck flag, is level 5 skill, equating a press with 0.65% of bodyweight or dips with ~37% added.
Both of these sources are at best anecdotal, so take them with a grain of salt. My suggestion, if a human flag is one of your goals, is to start training specifically for it as soon as possible. If you can hold the tuck flag for at least 10s, then add it to your routine and practice!

How much press strength for human flag?


How to use windows bootloader to dual boot windows and ubuntu on uefi?

Question: What I exactly tried is...
Installed windows 10 with uefi.
Installed Ubuntu 17.04 with uefi on the 20GB drive. The ubuntu bootloader is installed on the efi system partition created while installing windows 10, by selecting the "Windows Boot Manager" when asked for partitioning during wizard for installing Ubuntu.
So, after the installation of ubuntu, my EFI Firmware Menu (UEFI Boot Menu) shows like:
[SSD with windows(Legacy)]
[DVD-ROM]
[USB Drive]
[UEFI: USB Drive]
ubuntu
The default selection was the "ubuntu" and that lead to the grub loader.
What exactly I wanted was when I start my computer, windows boot loader must provide option like the blue screen as shown below, to select between the windows and ubuntu.
Bootloader Image That I want
So I tried booting from my windows 10 efi usb installed, select repair my computer and opened command prompt. And used bcdedit to edit the bootloader.
I make changes like...
deleted the "ubuntu" firmware application to remove the grub loader.
Add a "Windows Boot Loader" but command
<code>"bcdedit /create /d "Ubuntu" /application /osloader"</code>
and set path to "\EFI\ubuntu\shimx64.efi"
so my bcd configuration seems like k
Windows Boot Manager that links bootmgfw.efi.
Windows Boot Loader (Windows 10)that links winload.efi
Windows Boot Loader (Ubuntu) that links shimx64.efi //(That I added)
So I got the black and white Windows Boot Manager instead the Graphical Blue Boot loader and also its unable to boot to ubuntu by throwing an error.

What exactly I want is a blue screen with two options from windows blue boot loader and since I have uefi based installation, I can't use EasyBCD.
Please help.
Answer: Try EasyUEFI instead of EasyBCD
Comment: Could you please explain why?  That would make a much better answer.


where does kmeans store its trained model parameters in scikit learn?

Question: Like in linear regression, there is model.intercept_ and model.coef_ but in kmeans i found  kmeans.inertia_ , I dont know what is that.
Answer: K-means stores 4 model parameters namely cluster_centers_, labels_, inertia_, n_iter_. For details on what they store you can look at the official documentation. Also, Inertia, or the within-cluster sum of squares criterion, can be recognized as a measure of how internally coherent clusters are. You can see a full description here under the section: 2.3.2. K-means.