Why we need to use xmlns:android in xml design?
What does "xmlns" in XML mean?
When I'm editing a stack snippet, I often want to copy code from the original question into the snippet. But while the snippet editor is on display, there's no way to access the question, other than opening another tab/window. What I often do instead is copy all the code in the question to the clipboard, open the snippet editor, then paste it all in and revise it to what I want. But when the original code is poorly designed, that ends up being more work than just copying the bits and pieces that I want.  There could be a "View Question" button that pops up the question over the snippet editor and allows copying. Or maybe the Snippet Editor could be draggable and resizable, so you can reveal the question and copy from it; but this would require that it not be purely modal. X and Y are not correlated, but X is significant predictor of Y in multiple regression. What does it mean? X and Y are not correlated (-.01); however, when I place X in a multiple regression predicting Y, alongside three (A, B, C) other (related) variables, X and two other variables (A, B) are significant predictors of Y. Note that the two other (A, B) variables are significantly correlated with Y outside of the regression.   How should I interpret these findings? X predicts unique variance in Y, but since these are not correlated (Pearson), it is somehow difficult to interpret.  I know of opposite cases (i.e., two variables are correlated but regression is not significant) and those are relatively simpler to understand from a theoretical and statistical perspective. Note that some of the predictors are quite correlated (e.g., .70) but not to the extent that I would expect substantial multicollinearity. Maybe I am mistaken, though.    NOTE: I asked this question previously and it was closed. The rational was that this question is redundant with the question "". Perhaps I do not understand the other question, but I believe these are entirely separate questions, both mathematically and theoretically. My question is entirely independent from if "a regression is significant". Furthermore, several predictors are significant, while the other question entails variables not being significant, so I don't see the overlap. If these questions are redundant for reasons I do not understand, please insert a comment prior to closing this question. Also, I was hoping to message the moderator who closed the other question to avoid identical questions, but I couldn't find an option to do so. Problems with pie charts There seems to be in increasing discussion about pie charts.   The main arguments against it seem to be:   Area is perceived with less power than length. Pie charts have very low data-point-to-pixel ratio   However, I think they can be somehow useful when portraying proportions. I agree to use a table in most cases but when you are writing a business report and you've just included hundreds of tables why not having a pie chart?  I'm curious about what the community thinks about this topic. Further references are welcome.  I include a couple of links:         In order to conclude this question I decided to build an example of pie-chart vs waffle-chart. C# Structs: Unassigned local variable? I'm trying to educate myself on Granger Causality. I've read the posts on this site and several good articles online.  I also came across a very helpful tool, the , that allows you to enter your time series and calculate the Granger Stats.  Below, is the output from the sample data included on the site. I have also taken a crack at interpreting the results.   My Questions:     Is my interpretation directionally correct?   What key insights have I overlooked?   Also what is the meaning and interpretation of the CCF charts?  (I'm assuming CCF is cross correlation.)     Here are the results and plots that I have interpreted:  Summary of computational transaction Raw Input   view raw input (R code) Raw Output  view raw output of R engine Computing time  2 seconds R Server    'Herman Ole Andreas Wold' @ wold.wessa.net  Granger Causality Test: Y = f(X) Model   Res.DF  Diff. DF    F   p-value Complete model  356          Reduced model   357 -1  17.9144959720894    2.94360540545316e-05  Granger Causality Test: X = f(Y) Model   Res.DF  Diff. DF    F   p-value Complete model  356          Reduced model   357 -1  0.0929541667364279  0.760632773377753       My interpretation:    Test was based upon 357 data points and was performed with a lag value of 1 The p-value of 0.0000294 means I can reject the null hypothesis that x does not cause y for the Y = f(x). The p-value of .76 allows me to accept the null for X = f(Y) The fact that first hypothesis was rejected and second accepted is a good thing  I'm a little rusty on my F-test so I don't really have anything to say on this for now. I'm also not sure how to interpret the CCF graph.   I really appreciate it if any of you who are well versed with Granger-causality could let me know if I'm interpeting this correctly and also fill in some of the blanks.   Thanks for your help. What is the best way to convert an array to a hash in Ruby In Ruby, given an array in one of the following forms...  [apple, 1, banana, 2] [[apple, 1], [banana, 2]]   ...what is the best way to convert this into a hash in the form of...  {apple =&gt; 1, banana =&gt; 2} This question came up after reading , in which it is re-iterated (as it has been many times on this site), that investing in the stock market, especially an index fund that tracks the top 100 / 500 companies in a country, basically always has great returns in the long run.  So my question is: Why isn't everybody rich?  If it is so easy (basically invest as heavily as you can in your youth to be rich into middle age and older), why doesn't everyone do this? There would be no need for pensions or any other savings or financial security that way, why even bother investing in assets like property that you have to manage when you can just have an index fund work for you?  I'm guessing that something is being missed here. Let $x$ and $y$ be nonzero elements of an integral domain $D$. Then $x$ and $y$ are associates if and only if $x = yd$ for some unit $d \in D$.    I am done proving the $\Leftarrow$ part. For $\Rightarrow$ what I did was: If $x$ and $y$ are associates then $x \mid y$ and $y \mid x$, so $x \mid y$ implies that $xs = y$ for some $s \in D$ and $y \mid x$ implies that $yt = x$ for some $t \in D$. That is, $yts=y$ which implies $ts=1$. Therefore $s$ is a unit and $t$ is a unit.    Am I on the right track? Can I say that the proof is complete? I'm a little confused as to whether I should install Ubuntu on its own partition on my hard drive, use VirtualBox or another virtualization package to install it, or use Wubi to install it directly on top of my current OS (Win 7). I definitely want to learn and use Ubuntu, so this is not just for playing around with it.   Also, if I choose to partition, should I partition the hard drive myself or should I let the Ubuntu installation menu do it for me? I understand that I am going to need a main partition, for Ubuntu's core components, and also a swap partition. Then there is the option to add a partition for "home"- I don't understand what combination of these partitioning options I should choose, or whether it is better to partition in Windows before I install Ubuntu or just partition my hard drive when I install Ubuntu itself How to eliminate Cycles artifacts with many overlapping volumes? I have encountered an issue with Cycles Volumetrics in a recent scene. I am using Blender 2.72, and both CPU and GPU render options. In both I get a solid black artifact when I have two volumes overlapping, as in this campfire smoke test:    I have a solid cube, with a volume scatter and volume absorption material, duplicated by a particle system. As you can see, when the particles get higher up and farther apart, and are no longer overlapping, the artifacts disappear. What special characters must be escaped in regular expressions? I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps? I would like to remove my Raspberry Pi from my iPhone 8 (running iOS 11.2.1) as a connected bluetooth device.  Normally, I would go into my Settings -> Bluetooth and select the Info button (a small blue circled "i") to show the "Disconnect" and "Forget Device" dialogs:    Unfortunately, iOS does not give me this option for my device. The bluetooth device list does not contain an "i" for the item, and there is seemingly no other way to disconnect.    How do I unpair this device if there is no button to trigger to the unpair prompt?  Due to work restrictions I cannot completely reset the device. Text deselecting when using Logitech mouse scroll wheel in Sierra Failed to connect to socket /com/ubuntu/upstart: Connection refused: Errors were encountered while processing: runit How to avoid the 'not properly formatted as code' alert Why app updates download entire app instead of only "updates"? How to run find -exec? I'd like to find the files in the current directory that contain the text "chrome".  $ find . -exec grep chrome find: missing argument to `-exec'   What am I doing wrong? I am always confused about where to put adverbs in sentences. For example, consider the questions below:        Why did they target us specifically?   Why did they target specifically us?   Why did they specifically target us?      I believe all these sentences mean the same. Am I correct? I am always confused about where to put adverbs such as always and specifically, etc. Is there a particular grammar rule for this?  Funny, you see, I can even form the above sentence in different ways.         I always confuse where to put this kind of adverb   Always I confuse where to put this kind of adverb How to put an acute on an i using Biber: issues with "\'{\i}" I use some packages with require utf8. Here is the main file:  \documentclass[a4paper,titlepage]{report}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[american]{babel} \usepackage{csquotes} \usepackage[backend=biber,style=alphabetic]{biblatex} \addbibresource{refs.bib}  \begin{document} \nocite{*} \printbibliography[heading=bibintoc] \end{document}   And here is the reference file:  @MISC{Example,     author = {Author with spec\'{\i}al character},     title = {Title} }   I have no issues with composing special characters like \H{o} (ő) or \k{a} (ą). However, when I try to compose \'{\i} (í), I get the following inputenc error: "not set up for use with LaTeX". It seems like double compositions are not allowed. A solution is to use \'{i} instead, but not removing the dot is ugly. Surely there must be a better way?  Note: I have tried to add \DeclareUnicodeCharacter{00ED}{\'{\i}} to the preamble, but it doesn't help either. SQL query or method to list all sql services running This might be a simple one, but i searched a lot and unable to find one.  Is there a sql query or a way i can run on registered server to find the list of all sql related services running like, ssis , ssas, ssrs, sql, agent, broswer, etc...  Tried googling out and can find sys.dm_server_services dmv but it does not show all the services running