Recognize fonts
Replacing fonts in EPS/PDF files
Do you think there is a big difference in for...in and for loops? What kind of "for" do you prefer to use and why?  Let's say we have an array of associative arrays:  var myArray = [{'key': 'value'}, {'key': 'value1'}];   So we can iterate:  for (var i = 0; i &lt; myArray.length; i++)   And:  for (var i in myArray)   I don't see a big difference. Are there any performance issues? Is there ever a case where you would want to accept an answer, but not upvote it?  I can't think of a single situation where this would be the case.. So would it not make sense to have the "Accept" button upvote the answer too? Interpretation of p-value in Mann-Whitney rank test I am testing Mann-Whitney rank test with two vectors a and b. Vectors are almost similar so I expect a p-value near 0, but the returned p-value is near 1. What is the reason? I read  and also run the code with different parameters, but don't get anything near to what I expect.  from scipy.stats import mannwhitneyu import operator import numpy as np  a = [1000,100,10,1,10,100,1000,10000,1000,100,10,1] b = [999,100,10,1,10,100,1000,10000,1000,100,10,1]  print(mannwhitneyu(a, b))   The output of the code:  MannwhitneyuResult(statistic=73.5, pvalue=0.95291544831453867)   Edit:  Let's formalize the problem to eliminate any misunderstanding (please edit the question if something is wrong):  What I try to prove is that rank distribution of data are approximately equal,   Null hypothesis ($H_0$)= "ranked distribution of a and b are approximately equal"  Alternative hypothesis ($H_a$)= "ranked distribution of a and b are not equal"  significance level (alpha) = 0.05  p-value= 0.95  (p-value > alpha) so there is no sufficient evidence that $H_a$ is correct, but we cannot also conclude that ($H_0$) is true.   Instead if (p-value &lt; alpha) was true, then we would have enough evidence against H0 and Ha can be accepted.  So what happened here is that I could not disprove the null hypothesis. However, it doesn't mean that null hypothesis is false. It is like an investigation to accuse MR X of being guilty:   $H_0$=" MR X guilty" $H_a$=" MR X not guilty"  We guess he is not guilty, but we don't have enough proof against him: (p-value > alpha), but that doesn't mean that ($H_0$) would not be true. If we could obtain enough evidence and state (p-value &lt; alpha), then we disprove $H_0$ and we can conclude that Ha is true and he is not guilty. Why can I put an electrolytic capacitor on AC? I have seen here and there schematics with electrolytic capacitors put on AC. And this sounds weird to me.  Electrolytic capacitors have a polarity, right? If we invert the polarities on DC, bad things happen. As far as I understand, AC inverts polarity every now and then (commonly 50Hz). Why can we put such capacitors on AC without damaging them?  Example:    from demonstration here: Strict warning: Only variables should be passed by reference I get the following error:     Strict warning: Only variables should be passed by reference in include() (line 18 of /home/sites/dev/theparce/sites/all/themes/parce/block--block--3.tpl.php).   This is the block code which is causing that error.  if ($user_gallery) {   print render(node_show($user_gallery));  // Line 18   print drupal_render ($user_gallery_edit);  } else {   print drupal_render($user_gallery_new); }   Why do I get that error, even if I get all printed as expected? How to combine two jQuery results How do you combine two jQuery search results? eg:  var $allFoos = $('.foo'),     $allBars = $('.bar')     $allFoosAndBars = $allFoos + $allBars;   Obviously, I just made up that last line, but I hope it makes it sorta clear what I mean. To be clear, the example is greatly simplified, and it could be any arbitrary sets i'm talking about, so $('.foo, .bar') is not what I'm after. ufw: how to forward single port to another port on different interface I have two interfaces eth0 (192.168.1.2) and eth1 (192.168.3.2).  I receive data from 8080 at eth0. I want to forward it to eth1 port 80.  I'm using UFW, because i don't understand iptables and how to add it at the beggining of /etc/ufw/before.rules.  I've already edited DEFAULT_FORWARD_POLICY="ACCEPT" on /etc/default/ufw and already edited net.ipv4.ip_forward=1 on /etc/ufw/sysctl.conf Is there an online course in Mathematical Methods for Physics, Covering Matrices and Vector Analysis? I am taking a course in Mathematical Methods for physicsPhysics (Junior Level).   We are working from   > Mathematical Methods for physicists, George B.Arfken .    I just need online resources covering ( Matrices, Determinants, Vector Analysis, Tensors and differential forms and Vector spaces...etc) to study and understand from. 2D Integration With Quadratic Arg. of Delta Function In Ubuntu 17.10 ubuntu upgraded Nautilus (File Browser) to version 3.26.0. New nautilus is not using file-roller anymore, it has  to an integrated compression mechanism.     This makes it complicated to create encrypted archives and/or different types compression archives that file-roller does provide.  How to make nautilus use file-roller as before?  Related question: This doesn't work:  tar xf /tmp/foo.tar.gz foo/bar tar: foo/bar: Not found in archive   It's not obvious to me what would do this beyond extracting it in place and moving the files over. Decode Base64 data in Java Converting from DMS to DD using Python in Field Calculator? I found this in . I've paraphrased for clarity.  There are 100 professors. Some are honest, while others are dishonest. There are more honest professors than dishonest ones. Honest professors always tell the truth, but the dishonest ones sometimes tell the truth and sometimes lie. You can ask any professor the following question about any other professor, "Professor Y, is Professor X honest?" to which he/she will answer yes or no. Design an algorithm that allows you to figure out which of the professors are honest with no more than 198 questions.  The bold part is the kicker. If liars always lied, then the problem is trivial - just ask 99 people about one guy. The majority would be the truthful answer, so you know your honest guys and your liars.  So, any advice? If you give the answer please put it in spoiler tags since I'm just looking for direction. RELATED,ESTABLISHED state in iptables What do the words 'RELATED' and 'ESTABLISHED' individually signify in RELATED,ESTABLISHED state in iptables? I was trying to think but cannot figure it out. For instance, if the interaction is small, for instance limited to a windows, the observers in each universe will see that the other goes in reverse. But what if they can start a more meaningful interaction? (for instance, if one observer crosses the window and moves to the other universe, will anything change? why and how fast? (at least at the beginning his thinking will move in the same time arrow than in his universe, but the physical processes around him will still violate the second law? Where to start with the Star Wars books? Every once in a while, we get a question asking for a book or other educational reference on a particular topic at a particular level. This is a meta-question that collects all those links together. If you're looking for book recommendations, this is probably the place to start.  All the questions linked below, as well as others which deal with more specialized books, can be found under the tag  (formerly ).  If you have a question to add, please edit it in. However, make sure of a few things first:   The question should be tagged  It should be of the form "What are good books to learn/study [subject] at [level]?" It shouldn't duplicate a topic and level that's already on the list   Related Meta: Using old version of numpy even with a newer version installed Cardinality of a totally ordered union