Does spontaneous emission actually emit in a random direction, or is it measured in a random direction?

When an excited state couples to the vacuum, it has an infinite number of directions of the quantized electromagnetic field to couple to. Does it evolve into a superposition of all those directions at the same time and only collapses once the photon is measured, or does it couple to only one? (Or, of course, is there no experimental way to tell?)


If I get banned from a community will it stop showing up in Hot Questions?

If I get banned from a single community (as opposed to all of SE) will that communities hot questions stop appearing in my feed?  I like Hot Questions but due to  I've clicked into a few of them and I keep getting these sites in Hot Questions. I like Hot Questions as it shows me questions from new-to-me sites that I do find interesting which are outside of my usual interests.   There are some feature requests, workarounds, and user scripts to tune Hot Questions but I'd rather just not see these sites at all.


if someone beat me to it should I delete my answer

If I submit an answer only to find out that someone just answered X seconds before me with the same answer, should I delete my answer?


MSO Review Queue Privileges are Misleading

When I visit Stack Overflow, I see the review option in the bar at the top of the screen.    However when on MSO, I don't see it. I assumed this was because I didn't have enough reputation to access the queue. I was curious what the requirement was on meta, so I moseyed on over to the privileges page. To my surprise, I saw that the privilege is listed as only requiring 500 rep and informs me I already have it:    Confused, I manually typed in meta.stackoverflow.com/review to see what would happen. The page did in fact load, but as you can see meta has no "First Posts" or "Late Answers" queue.    Seeing on that page that a minimum of 2k reputation is required to access any queues on MSO, I report the following bug:  1) On the privileges list on MSO, the 500 rep privilege of "Access first posts and late answers review queues" should not appear.  I also have the following feature request:  2) On the privileges list on MSO, it would be useful if instead there was a 2k privilege that informed you that you have access to the "Suggested Edits" and "Low Quality Posts" queues.


Python multiplication operation returns false repeating decimal

I was doing my program for a school project when I encountered a problem which I'm unable to understand after trying many different methods to resolve it. I have a function that does a simple mathematical operation like this:  def pikkus(kogupikkus, loimed):     summa = loimed * (kogupikkus * 1.2 + 0.5)     return (summa)   Now, when giving the function numbers 4.9 and 140 (in this same order), it returns me a number which isn't true, because 4.9 * 1.2 + 0.5 = 6.38 and 140 * 6.38 = 893.2, but all I get is 893.1999999999999, but it's not even true, try doing 140 * 6.38 yourself - it's exactly 893.2 PS! It has to be a float number, it's in my project instructions that it can't be rounded to an integer, so answers like "just put a round() infront and you are good" don't help me at all.


Why can't I update applications without upgrading the whole OS?

In Ubuntu, once a release is out the software one has installed receives security updates only. In Windows, I can get new versions of programs with new features. How can Windows do this and why can't Ubuntu?


Can anybody give me some link which proves that winding number is an integer in complex analysis. In most of the links I found they approached in assuming that $$s \mapsto \int_{0}^{s} \frac {\gamma'(t)} {\gamma (t)-a}\ dt$$ is continuous on $[0,1]$ and differentiable on $[0,1]$ except possibly at junction points where $\gamma$ is closed contour with parametric interval $[0,1]$ and $a \notin \{\gamma \}$. I don't understand this thing clearly. So I want a proof which has some clear discussion. Please help me by giving it if there is any.  Thank you in advance.


Formulars displayed "raw" in Android App

Mathematic formulars in titles are not displayed correctly in the Android App. Always I see the "raw" code behind it.  If I switch to view in browser e.g. using Chrome, it works again.  One example is this    I am using version 1.0.89 on a Samsung Galaxy S5 mini with Android 5.1.1  Is this known?


Explain reflection laws at the atomic level

The "equal angles" law of refection on a flat mirror is a macroscopic phenomenon. To put it in anthropomorphic terms, how do individual photons know the orientation of the mirror so as to bounce off in the correct direction?


How to convert image of map into vector format?

What is the best way of converting a gif of a map into a vector format, such as a shapefile?   The only relevant parts that I am interested in are the outline of the island so I realize some manual work will be necessary where it is shaded orange; is there a way to handle the rest?  Regarding copyright, it's from the 1980s and it's being used for academic research.


I haven't used regular expressions at all, so I'm having difficulty troubleshooting. I want the regex to match only when the contained string is all numbers; but with the two examples below it is matching a string that contains all numbers plus an equals sign like "1234=4321". I'm sure there's a way to change this behavior, but as I said, I've never really done much with regular expressions.  string compare = "1234=4321"; Regex regex = new Regex(@"[\d]");  if (regex.IsMatch(compare)) {      //true }  regex = new Regex("[0-9]");  if (regex.IsMatch(compare)) {      //true }   In case it matters, I'm using C# and .NET2.0.


Whats wrong with this specified code in this java code?

class Pointgrejen{     public static void main (String [] args){         int[] a = new int[5];         a[3] = 7;          Point[] b = new Point[5];         b[3].x = 7;           System.out.print(a[3]);         System.out.print(b[3]);     } }   Why isn't the program executing? Point is a java class in java, but is the error in this code that I havent defined what type of data the array should hold in the point array? Or whats the bigger issue with this code?


Which of the seeded humanoid species was the first to be warp-capable?

In Star Trek - TNG S6E20 The Chase, the apparently first humanoid species in the Galaxy from around 4.5 Billion years ago appear, travel the galaxy and spread their genetic material on terraformed planets. In the episode, it is stated that they were the only humanoids and seeded genetic information for new humanoids to evolve on some of the primordial worlds they discovered. The recording asserts that no other humanoids existed when these seeders existed and that they specifically seeded humanoids like themselves (or at least raw material which would eventually evolve into a humanoid species with very similar co-compatible DNA)  We also know that this original species was obviously warp capable, and others likely existed at that time (such as the Crystalline Entity, and likely the Founders). I'm not asking about the first warp-capable beings in the universe. This is about a sort of "space race" between the humanoids these guys spread around - a limited set of species.  This has nothing at all to do with "inventing" warp technology either - not interested in the smartest race. If someone stole the technology from the Dominion, they won the race. If someone rides around on saddles on a Crystalline entity first, they won the race. It's about which species evolved into a humanoid and then knocked on a neighbor's door first, no matter how they got there.  The answer will be based on in-universe current information. The exact number of different species which evolved is unknown and all the different species created this way are unknown. But from what we DO know, which species was warping around the galaxy first?    Disambiguation   This question specifically does not want speculation about ancient civilizations before The Chase founders (who traveled the galaxy by some arbitrary and undocumented means.) . (Some races steal technology which leads to advances without invention, & sometimes technology travels back through time in a temporal incursion. Those were excluded from the other question but are all valid contenders here. This question is NOT asking about the entire galaxy. Many species have traveled at warp for a very long time before humanoids did (The Founders have been . But the Founders are not in this race. Did they give warp tech to a humanoid species? Now THAT is relevant. This question is NOT asking for political or ethnic collectives like“The Borg” or “United Federation of Planets.” This is about a species - distinct genetically identifiable and who share a common ancestor via this "seeding" process. In Star Trek time travel sometimes brings things into existence without ever inventing them . No one on earth invented the transparent aluminum used in 1986 San Francisco which spontaneously arose in a predestination paradox.


Attempting to compile any kernels, even vanilla ones, yields a certification error (continued from last thread)

(Accidentally lost previous account after crashing my computer without saving keepass information. Continuing thread here).  I'm currently attempting to follow  guide  in order to install the 4.5.7 kernel with Grsecurity on my Kali Linux desktop. I am following that list of instructions verbatim, except for the fact that I'm trying to use Grsecurity's test patch for the 4.5.7 kernel and I'm running Kali Linux instead of straight Debian. Every time I attempt to compile the kernel, however, I get this error following the line "CC certs/system_keyring.o":    CC      certs/system_keyring.o make[2]: *** No rule to make target 'debian/certs/benh@debian.org.cert.pem', needed by 'certs/x509_certificate_list'.  Stop. Makefile:951: recipe for target 'certs' failed make[1]: *** [certs] Error 2 make[1]: Leaving directory '/home/jc/Downloads/linux-4.5.7' debian/ruleset/targets/common.mk:295: recipe for target 'debian/stamp/build/kernel' failed make: *** [debian/stamp/build/kernel] Error 2   I get this error, as I found out, for any kernel even if I apply no patches or modifications, so it has something to do with the tools I'm using to compile the kernel (apparently a system keychain of some sort). This is my first custom kernel, I'm not the most proficient at Linux, and I'm not sure what to make of the error. Can someone out there tell me how to fix my OS and compile my kernel? Bonus points if you can help someone really nooby understand what the problem was.  Thanks, John.  P.S., if it helps, here is the output of cat /proc/version:  Linux version 4.6.0-kali1-amd64 (devel@kali.org) (gcc version 5.4.0 20160609 (Debian 5.4.0-4) ) #1 SMP Debian 4.6.2-2kali2 (2016-06-28)   UPDATE 1: Suggested method  of adding --uc and --us to the make-kpkg command gave me the same error.


What are all possible automorphisms of the Klein's 4-group?

Let $G$ denote the Klein's 4-group; that is, let $G \colon= \{e, a, b, ab\} $, $\ a^2 = b^2 = e$, $\ $ $ab = ba$. Then what are all the possible automorphisms of $G$?   My work:   Under an automorphism $T$, the element $a$ has three choices for an image, then $b$ has two, and finally $ab$ has only one, thus giving a total of six possible automorphisms.   Is my reasoning correct?


How do I get the UTC time of "midnight" for a given timezone?

The best I can come up with for now is this monstrosity:  >>> datetime.utcnow() \ ...   .replace(tzinfo=pytz.UTC) \ ...   .astimezone(pytz.timezone("Australia/Melbourne")) \ ...   .replace(hour=0,minute=0,second=0,microsecond=0) \ ...   .astimezone(pytz.UTC) \ ...   .replace(tzinfo=None) datetime.datetime(2008, 12, 16, 13, 0)   I.e., in English, get the current time (in UTC), convert it to some other timezone, set the time to midnight, then convert back to UTC.  I'm not just using now() or localtime() as that would use the server's timezone, not the user's timezone.  I can't help feeling I'm missing something, any ideas?


An Inequality about complex numbers with non-negative real and imaginary parts

Let $z_1,z_2  \dots dots z_n \in \mathbb{C} $ be such that the real and imaginary parts of each z_i are non-negative. Show that  $\Big|\sum_{i=1}^{n} z_i\Big| \geq\frac{1}{\sqrt{2}}\sum_{i=1}^{n} |z_i|$  I couldn't start this problem. I tried to get a geometric view of this but that didn't help


How does Newton's first law asserts the existence of inertial frames?

Recently I've seem  one answer telling that Newton's first law really assures the existence of inertial reference frames. But how is that? I really can't see it. As I know, Newton's first law says:     Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.   Now, what I've seem done is to use this to define that whenever this law holds in some reference frame we call it inertial. But how this law states that such a frame does exist?


How to solve the equation $15x- 16y= 10$

I am trying to find an $x$ and $y$ that solve the equation $15x - 16y = 10$, usually in this type of question I would use Euclidean Algorithm to find an $x$ and $y$ but it doesn't seem to work for this one. Computing the GCD just gives me $16 = 15 + 1$ and then $1 = 16 - 15$ which doesn't really help me. I can do this question with trial and error but was wondering if there was a method to it.  Thank you


Is continuous bijection $f:\mathbb{R} \to \mathbb{R}$ necessarily differentiable?

There are a number of continuous but nowhere-differentiable functions, none of which (to my knowledge) are bijections. I am wondering if continuous bijection $f:\mathbb{R} \to \mathbb{R}$ is necessarily everywhere-differentiable. I would think so, but am not sure how to formally approach this problem and have not found a similar question on MSE.


Windows 10 virtual desktops - preserve taskbar order

Is there a way to preserve the taskbar order while switching between virtual desktops in Windows 10? The order resets on my PC every time, and that's very annoying.


I've run accross a strange behaviour of the click event I can (more or less) figure out but I can't find documentation about.  Is it possibile to click a button using method click() from within a promise then or using a setTimeout function?  Here's an example to show what I mean:  document.getElementById("mioBottone").addEventListener("click", function () {     callAPI().then(function (data) {         document.getElementById("inputFile").click();     }); });  function callAPI () {     return new Promise (function (resolve, reject) {         $.get( "https://swapi.co/api/people/1/", function( data ) {             resolve(data);         });     }); }   From my tests it looks like click can be only executed in click event listener context and not delayed using promises or setTimeout, but I haven't found any documentation about it.  And here's a simple fiddle:


How how do I query recent account views and group by LastViewedDate    SELECT Id, Name                 FROM Account                ORDER BY Name DESC limit 10 FOR VIEW   I used to have it like this, but my test case is keep failing  SELECT SELECT Id, Name, LastModifiedDate                         FROM account                         WHERE LastModifiedDate !=null ORDER BY LastViewedDate DESC limit 10  static testmethod void testOppExt_TestMethod(){        Opportunity testOpp = new Opportunity(Name = 'TestOpp', StageName='Test', CloseDate = Date.today());       insert testOpp;        Account testAcc = new Account(Name = 'Test Account');       insert testAcc;        Contact con = new Contact(LastName='Test',AccountId=testAcc.id);       insert con;        Test.startTest();       OppExt testCon = new OppExt();       Contact conn = testCon.contact;       Account  Accn = testCon.acc;       Test.stopTest();     }   Error Message   Component Errors API Name Type Line Column Error Message 0 0 , Details: Average test coverage across all Apex Classes and Triggers is 0%, at least 75% test coverage is required. 0 0 SiteRegisterControllerTest.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteLoginControllerTest.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteRegisterController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 testnewOpportunityController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 SiteLoginController.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 testOppExt.null(), Details: line -1, column -1: Previous load of class failed: oppext null 0 0 OppExt.null(), Details: line 32, column 17: No such column 'LastViewedDate' on entity 'Account'. If you are attempting to use a custom field, be sure to append the '__c' after the custom field name. Please reference your WSDL or the describe call for the appropriate names. null


What should I do if I am getting negative results for Cronbach's alpha? Is there anyway to adjust it?


How do I insert data into my android app

Like I'm trying to develop an application that already has data(paragraphs) . So the user will basically press a button to open up the specific texts.   From the tutorials I've done, I can only add them from the app, while I would want them to already come with the app. how would I go about this with sqlite or should I use something else?


Loop program back to start point after it's finished

So I've created this program which manipulates a word that the user gives as input, by taking the moving the first character to the end of the word, spells the rest of the word backwards, then checks if the original word and the new word are the same. It's designed to run until the user enters the word "quit" as the chosen word. I've managed to get the majority of the code working, except, instead of looping back to ask the user for a new word after its checked the previous one, it just continues running forever. The code I've currently got is below:  package uploadTask9_wordPlay;  import java.util.Scanner;  public class wordPlay {      public static void main(String[] args) {         // creates scanner object to get a name from the user input         Scanner userInput = new Scanner(System.in);              System.out.println("Enter a name to be tested, or 'quit' to exit  program: ");             // stores the user input into string testedName             String testedName = userInput.nextLine();              // if the user input is "quit", program exits             if (testedName.equals("quit")) {                 System.out.println("Thanks for using the program");                 System.exit(0);             }              // else, do the rest of the code with the given word             else {                  while (testedName != "quit") {              // takes first character from userInput             char firstLetter = testedName.charAt(0);              // removes first character from testedName             StringBuilder removeChar = new StringBuilder(testedName);             removeChar.deleteCharAt(0);              // adds first character of testedName to the end of removeChar             String newString = removeChar.toString() + firstLetter;              // prints newString backwards             String reverseWord = new  StringBuffer(newString).reverse().toString();              // if statement - far simpler way to carry this task out than loops             // if statement to check if the words are the same             if (testedName.equals(reverseWord)) {                  System.out.println(testedName + " is the same as " + reverseWord); }              else {                   System.out.println(testedName + " is not the same as " + reverseWord); }          }        }        } }   Does anyone know why the program doesn't loop back to the start each time its checked a word?


TikZ: Replacing the values (labels) on x-axis with names

I managed to create a simple linear plot with pgfplots-manual (chapter 4.5.1)    Now I want to replace the values of x-axis (1,2,3,4) with text, e.g.Test A, Test B, Test C, Test D. How can I do such a configuration?  MWE:       \documentclass[12pt,ngerman]{article}     \usepackage{pgfplots}     \pgfplotsset{width=7cm,compat=1.10}      \begin{document}      \begin{tikzpicture}     \begin{axis}         [         xlabel={Test},         ylabel={Mean}         ]     \addplot+[sharp plot] coordinates     {(0,18.26) (1,21.47) (2,24.58) (3,24.95)};     \end{axis}     \end{tikzpicture}      \end{document}


I was just looking for whether StackOverflow can be localized somehow or what the current state of development is regarding this topic. But it is difficult to find anything because I get lots of old questions, which are now not interesting.  I've encountered the same thing sometimes on SO: you search for something (e.g. JavaScript) and find a lot of things that are already outdated.  So how can I filter out such questions?


How to apply for a Schengen visa when the travel dates are uncertain

My husband has a Chinese passport and I am a U.S. citizen; I don't need a visa to travel to Schengen countries. I am helping him to apply for a visa.  Our plans are to go to Paris, Italy and Spain, but we haven't nailed down definite dates; the approximate dates are August 18 to September 11. We made an appointment with Spain consulate to apply for the visa. We need to show air flight reservations, I could book it online without any problems.    Since we don't have definite dates, what dates should he put down on the application?  I know that, once they approve you, they give you 90 days, so does it matter what dates I put down on the visa application?   Our appointment at the Spanish Consulate is in a few days.


Wave Packets, Group velocity, and Phase velocity

Mathematically, you find that the wave function of a particle $\Psi (x,t)$ moves with the same velocity as the velocity of the particle ($v_{particle} = v_{group}$).  Is there a reason why the particle velocity should not equal the phase velocity?


New Ubuntu 12.04 LTS user here.  I have downloaded Google Earth, it shows as its downloaded but says it must be operated from a terminal.  Could someone please explain what terminal means in that context. Thanks, Steve


Find the value of $\sum_{k=1}^{n} k \binom {n} {k}$

I was assigned the following problem: find the value of $$\sum_{k=1}^{n} k \binom {n} {k}$$ by using the derivative of $(1+x)^n$, but I'm basically clueless. Can anyone give me a hint?


Accepted as PhD student, but my funding application was rejected. Now my prospective PhD advisor recommends that I should bail out. What should I do?

I was recently accepted by a university as a PhD student. During the whole process, my potential supervisor agreed to supervise me along with some of his colleagues as my co-supervisor. Although, I have been accepted as a PhD student by the university, but I didn't get the scholarship. I a mentally as well as financially prepared for the expenses. But now my supervisor is saying that I should decline the offer. I told him that I can manage my expenses, but in every mail he is giving me some other excuse for not accepting this offer. I am confused now as to what I should do. Since the graduate school has accepted me, now it's up to me whether I should accept or not. But I am not able to understand why my supervisor is not willing to take me. Any suggestions for what should I do now are highly appreciated. Thank You.


Tag scores displayed on the Tags tab and the Tag Badge tracker do not match

On my profile page , in the Activity tab, below the block where reputation is displayed, I have set up the C# badge tracker. It shows:    As you can see, I have 21 / 20 answers and 15 / 100 score. But in the tags page, it shows:    So, which one is the correct one? Why is it even different? Or am I confusing the two things which are completely different from each other?  There are a few questions which ask about calculations of tag badge scores, etc. But I could not find one which shows that the tracker and the tag page have different scores. So I don't think this is a duplicate.  UPDATE  The solution of the problem is to select some other badge to track and then re-selecting the C# badge. I wonder why it doesn't update by itself.


Today I've come across this command for extracting domain name from domain controller's FQDN:  DOMAIN_NAME=$(echo $DC_PC | sed -r 's!^[^.]+\.!!')   What is the meaning of these exclamation marks in sed? How does it work?


In Vim is there a way to delete without putting text in the register?

Using Vim I often want to replace a block of code with a block that I just yanked.  But when I delete the block of code that is to be replaced, that block itself goes into the register which erases the block I just yanked. So I've got in the habit of yanking, then inserting, then deleting what I didn't want, but with large blocks of code this gets messy trying to keep the inserted block and the block to delete separate.  So what is the slickest and quickest way to replace text in Vim?   is there a way to delete text without putting it into the register? is there a way to say e.g. "replace next word" or "replace up to next paragraph" or is the best way to somehow use the multi-register feature?


Is this a 'proper' way to represent a circuit schematic?

Is this a reasonable way to do a wiring diagramme. What are the common practices when making this sort of thing?  Basically I am a compleat beginner and would love to know if this is a proper neat way to represent a circuit schematic.


Center nodes near coords in a stacked ybar plot

I'm trying to center the node values, at the middle of each bar, in a stacked plot. However I can only put those nodes in the top of each bar. Is it possible to move those down? To the center of each bar to be more precise.  \documentclass{article}  \usepackage{tikz} \usepackage{pgfplots}  \begin{document} \begin{tikzpicture} \begin{axis}[ x tick label style={ /pgf/number format/1000 sep=}, ylabel=Population, enlargelimits=0.05, legend style={at={(0.5,-0.15)}, anchor=north,legend columns=-1}, ybar stacked, nodes near coords, nodes near coords align={center}, ] \addplot coordinates {(1930,50e6) (1940,33e6) (1950,40e6) (1960,50e6) (1970,70e6)}; \addplot coordinates {(1930,38e6) (1940,42e6) (1950,43e6) (1960,45e6) (1970,65e6)}; \addplot coordinates {(1930,15e6) (1940,12e6) (1950,13e6) (1960,25e6) (1970,35e6)}; \addplot coordinates {(1930,15e6) (1940,12e6) (1950,13e6) (1960,25e6) (1970,35e6)};  \legend{Far,Near,Here,There} \end{axis} \end{tikzpicture} \end{document}   So this is what I got     Edit  Ok, thanks to Jake now the example above works. I also notice that my example using floats wasn't working because I didn't use the \makeatletter after the document.  However, when I'm using float values using the solution the bars don't appear as they are when not using them.  Before using the values:    And after the example I got:    The code is this  \documentclass{standalone}  \usepackage{tikz} \usepackage{pgfplots}  \pgfplotstableread{ 1   19.178  26.027  8.219   6.849   39.726 2   54.795  21.918  4.110   6.849   12.329 3   28.767  16.438  6.849   8.219   39.726 4   63.014  2.740   2.740   2.740   28.767 5   90.411  1.370   6.849   0.000   1.370 6   15.068  2.740   16.438  8.219   57.534 7   67.123  0.000   0.000   0.000   32.877 8   72.603  6.849   5.479   0.000   15.068 9   56.164  12.329  6.849   4.110   20.548 10  50.685  4.110   8.219   1.370   35.616 }\datatable  \begin{document} \makeatletter \begin{tikzpicture} \begin{axis}[     ylabel=label,     xtick=data,     xticklabels={S1,S2,S3,S4,S5,S6,S7,S8,S9,S10},     enlarge y limits=false,     enlarge x limits=0.1,     ymin=0,ymax=100,     ybar stacked,     bar width=10pt,     legend style={       font=\footnotesize,       cells={anchor=west},       legend columns=5,       at={(0.5,-0.15)},       anchor=north,       /tikz/every even column/.append style={column sep=0.2cm}     },     % Comment from here to produce the first plot     point meta=explicit,     calculate offset/.code={         \pgfkeys{/pgf/fpu=true,/pgf/fpu/output format=fixed}         \pgfmathsetmacro\testmacro{(\pgfplotspointmeta*10^\pgfplots@data@scale@trafo@EXPONENT@y)/2*\pgfplots@y@veclength)}         \pgfkeys{/pgf/fpu=false}     },     every node near coord/.style={         /pgfplots/calculate offset,         yshift=-\testmacro     },     nodes near coords,     nodes near coords align=center ] \addplot table [meta index=1] \datatable; \addplot table [y=1, meta index=2] \datatable; \addplot table [y=2, meta index=3] \datatable; \addplot table [y=3, meta index=4] \datatable; \addplot table [y=4, meta index=5] \datatable; % This code produces the first plot %\addplot table[x index=0,y index=1] \datatable; %\addplot table[x index=0,y index=2] \datatable; %\addplot table[x index=0,y index=3] \datatable; %\addplot table[x index=0,y index=4] \datatable; %\addplot table[x index=0,y index=5] \datatable; \legend{Far,Near,Here,There,NotThere} \end{axis} \end{tikzpicture} \end{document}


Hidden $RECYCLE.BIN folder taking up 30GB in brand new drive

I've just recently acquired a 1TB disk, and installed it on my computer. It barely has any files on it (specifically, only a 3KB password file), but Windows Explorer says it has 35GB in use.  As you can see, there is a lot of space in use. However, when browsing the contents of the drive, there is nothing notably large to see. (Show Hidden Files is enabled, by the way)  This seems very strange for a new drive. Maybe it's something related to caching? My computer surely does have more than enough RAM for operating. EDIT: Following the answer in @ChrisInEdmonton's dupe hint, I discovered that there is a 30GB $RECYCLE.BIN folder taking up 30GB, in addition to the System Volume Information folder, with 5GB in it. Is it safe to remove this folder?


Whenever someone thinks about silent cinema the image of the laughing villain, twirling his mustache, and tying the hapless blonde beauty to the railroad, pops up in our collective memory. But in which movie (or movies) did that particular image first appear?


Fourier transform of a measure (A qualifying exam problem from a UC, Help!!)

here is a qualifying exam problem and my best attempt thus far: (This is a previous problem, I'm not taking it right now.) Problem: if $(\mathbb{R},\mu)$ is a finite Borel measure and $\phi(t)=\int e^{ixt}\,d\mu(x)$ is its Fourier transform if furthermore $\mu(\{x\})=0$ for any $x\in \mathbb{R}$, prove that $$\frac{1}{T}\int_{-T}^T|\phi(t)|^2\,dt\rightarrow 0$$ as $T\rightarrow\infty$. My attempt is to write $$\int_{-T}^T|\phi(t)|^2\,dt=\int\int_{-T}^Te^{-itx}\phi(t)\,dt\,d\mu(x).$$ While the inversion theorem says that $$\int_a^b\int_{-T}^Te^{-itx}\phi(t)\,dt\,dx\rightarrow 2\pi\mu([a,b])$$ as $T\rightarrow\infty$ and somehow go from here. But I'm kind of stuck. Please help me!! Thanks!! Oh, actually this follows from


Problem in notation: $(\vec{v}\cdot\vec{\nabla})\vec{v}$ versus $L_v(\vec{v})$

I've seen more than one time the use of the following notation: $(\vec{v}\cdot\vec{\nabla})\vec{v}$ to say $L_v(\vec{v})$ where the matrix $L_v$ is defined as follows: $(L_v)_{ij} := \partial_j v_i$. For example this happens in the usual law of conservation of momentum of an eulerian fluid: $$\rho\Big(\partial_t\vec{v} + (\vec{v}\cdot\vec{\nabla})\vec{v}\Big) = \rho\vec{b} + \vec{\nabla}p$$ My question is: how that notation could "help" us to understand "how things work"? I think this is strange, but physicists are known to have strange notations that in some ways help to understand the nature of things. Take for example the divergence of a vector field $\vec{v}\ $: this is written in some texts as $\vec{\nabla}\cdot\vec{v}$ because if we think at $\vec{\nabla}$ as the vector $(\partial_1, \partial_2, \partial_3)$ then the scalar product $$\vec{\nabla}\cdot\vec{v} = (\partial_1, \partial_2, \partial_3) \cdot (v_1,v_2,v_3) = \sum_{i=1,2,3} \partial_i \ v_i = \text{div}(\vec{v})$$ Now, if I take for example a $2$ dimensional field $\vec{v} = (v_1,v_2)$ we have (correct me if I'm wrong) $$L_v(\vec{v}) =  \begin{pmatrix} \partial_1 v_1 & \partial_2 v_1 \\  \partial_1 v_2 & \partial_2 v_2 \end{pmatrix} \begin{pmatrix} v_1 \\ v_2 \end{pmatrix} = \begin{pmatrix} (\partial_1 v_1)v_1 + (\partial_2 v_1)v_2 \\  (\partial_1 v_2)v_1 + (\partial_2 v_2)v_2 \end{pmatrix} $$ How could I derive "intuitively" the last vector using the notation $(\vec{v}\cdot\vec{\nabla})\vec{v}$?


How can I easily find questions that I can answer

I am a jack of many trades but master of none. Filtering by tag names typically gives me advanced questions that I cannot answer. I started using a different Q&A site recently. Is seems to show me a lot of questions that I can answer.


Getting apt-get errors after unsuccessful Oracle Java instalation

I started getting errors when installing packages using apt-get after unsuccessful Oracle JDK 7 installation.These errors come up even when I'm installing packages unrelated to Java. For some reason apt-get tries to install jdk (and fails) every time I install something. Here is the output from when I try to install vim: How can I fix this?  Reading package lists... Done Building dependency tree        Reading state information... Done Suggested packages:   ctags vim-doc vim-scripts The following NEW packages will be installed:   vim 0 upgraded, 1 newly installed, 0 to remove and 45 not upgraded. 1 not fully installed or removed. Need to get 1 036 kB of archives. After this operation, 2 458 kB of additional disk space will be used. Get:1 http://lv.archive.ubuntu.com/ubuntu xenial-updates/main amd64 vim amd64 2:7.4.1689-3ubuntu1.2 [1 036 kB] Fetched 1 036 kB in 0s (1 778 kB/s) Selecting previously unselected package vim. (Reading database ... 266223 files and directories currently installed.) Preparing to unpack .../vim_2%3a7.4.1689-3ubuntu1.2_amd64.deb ... Unpacking vim (2:7.4.1689-3ubuntu1.2) ... Setting up oracle-java7-installer (7u80+7u60arm-0~webupd8~1) ... Downloading Oracle Java 7... --2017-12-09 21:57:26--  http://download.oracle.com/otn-pub/java/jdk/7u80-b15/jdk-7u80-linux-x64.tar.gz Resolving download.oracle.com (download.oracle.com)... 81.198.165.219, 81.198.165.233 Connecting to download.oracle.com (download.oracle.com)|81.198.165.219|:80... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: https://edelivery.oracle.com/otn-pub/java/jdk/7u80-b15/jdk-7u80-linux-x64.tar.gz [following] --2017-12-09 21:57:26--  https://edelivery.oracle.com/otn-pub/java/jdk/7u80-b15/jdk-7u80-linux-x64.tar.gz Resolving edelivery.oracle.com (edelivery.oracle.com)... 184.86.54.138, 2a02:26f0:18:489::2d3e, 2a02:26f0:18:499::2d3e Connecting to edelivery.oracle.com (edelivery.oracle.com)|184.86.54.138|:443... connected. HTTP request sent, awaiting response... 302 Moved Temporarily Location: http://download.oracle.com/otn-pub/java/jdk/7u80-b15/jdk-7u80-linux-x64.tar.gz?AuthParam=1512849566_e3b01a3ab3696363f4f5cbd105ec04d6 [following] --2017-12-09 21:57:26--  http://download.oracle.com/otn-pub/java/jdk/7u80-b15/jdk-7u80-linux-x64.tar.gz?AuthParam=1512849566_e3b01a3ab3696363f4f5cbd105ec04d6 Connecting to download.oracle.com (download.oracle.com)|81.198.165.219|:80... connected. HTTP request sent, awaiting response... 404 Not Found 2017-12-09 21:57:26 ERROR 404: Not Found.  download failed Oracle JDK 7 is NOT installed. dpkg: error processing package oracle-java7-installer (--configure):  subprocess installed post-installation script returned error exit status 1 Setting up vim (2:7.4.1689-3ubuntu1.2) ... update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vim (vim) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vimdiff (vimdiff) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/rvim (rvim) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/rview (rview) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vi (vi) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/view (view) in auto mode update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/ex (ex) in auto mode Errors were encountered while processing:  oracle-java7-installer E: Sub-process /usr/bin/dpkg returned an error code (1)


Why do we cite books with publisher and city?

Or just city in some formats? I mean, I could maybe guess why it was marginally helpful a century ago, but why now? What use is it for my reader to know that a book I'm citing was published in Berlin, Boston, and Fresno, or more to the point, that the nearest city to me where a certain book was printed years ago happens to be Fresno? If the point is to look up the book, wouldn't the ISBN be far more useful?


I want to flip line orders of a document with 500+ lines. The lines aren't just numbers, some include text and other characters. It's a mix.  Example:   Line 1 Line 2 Line 3 Line 4 Line 5 Line 6   Which I then want to flip, reverse and look like this from bottom to top:   Line 6 Line 5 Line 4 Line 3 Line 2 Line 1


mod-rewrite - sending any URL with ".php/" to 404

I have a substantial number of rewrite rules in place for a variety of reasons such as:  disallow indexes, set custom error pages, force non-www, https, strip trailing slash, redirect index.html or.php to root, pretty URLs (hides file extensions & queries), 404 any URL with Additional Path Info   I was having trouble with nonsense URLs (URLs with Additional Path Info) invoking broken pages & 500 errors that were being indexed as duplicates by search engines.  Sample: example.com/index.php/somefolder/another/file/query...   I set up rules to redirect to a default page rather than rendering broken pages or 500 errors. I then modified that same block to send such nonsense URLs to 404 instead so they would not be indexed.  MrWhite educated me on the proper use of AcceptPathInfo Off but unfortunately this had no effect.  The current solution (full array shown below) requires additional .htaccess files inside any sub-directories containing accessible pages but it worked like a charm.   This is the full array of rules currently in place. Everything is now working perfectly. I'm currently working to eliminate the need for the additional htaccess files in the subdirectories.  AcceptPathInfo Off     Options -Indexes  Options +FollowSymLinks RewriteEngine On RewriteBase /  ## 404 ANY URL WITH ADDITIONAL PATH INFO ## RewriteCond %{THE_REQUEST} /([^.]+)\.php/? [NC]  RewriteRule ^ /%1 [NC,R=404,L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^([^/]+)/?$ /$1.php [L,NC]  ## SET CUSTOM ERROR PAGES ## ErrorDocument 400 /error/error_400.php ErrorDocument 401 /error/error_401.php ErrorDocument 403 /error/error_403.php ErrorDocument 404 /error/error_404.php ErrorDocument 500 /error/error_500.php  ## FORCE HTTPS & NON-WWW ## ## RewriteEngine On  RewriteCond %{SERVER_PORT} 80  RewriteRule ^(.*)$ https://dev.example.com/$1 [R=301,L,NE]  ## STRIP TRAILING SLASH ## RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)/$ /$1 [R=301,L]  ## REDIRECT INDEX TO ROOT ## RewriteRule ^index\.php$ / [R=301,L] RewriteRule ^index\.htm$ / [R=301,L]  ## PRETTY URLS FOR DYNAMIC FILES ## RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^items/([a-zA-Z0-9_-]+)$ item.php?item=$1 [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^items/([a-zA-Z0-9_-]+)/$ item.php?item=$1 [L]  ## PRETTY URL FOR ANY STATIC FILE ## RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !-f RewriteRule ^([a-zA-Z0-9_-]+)$ $1.php [L,QSA]   The block labeled "404 ANY URL WITH ADDITIONAL PATH INFO" would be unnecessary if the "AdditionalPathInfo off" directive would work. This setting can also be controlled in the httpd-conf file on the server. Editing httpd-conf requires command-line, ssh access and can be dangerous. Consult your hosting company or server admin if that sounds scary.   Currently using feedback I've received here to clean this up. Updates to come.


What is the difference between apt-get update and upgrade?

What is the difference between apt-get update and apt-get upgrade?  Which should I run first?  Do any of them automatically run the other?


$P$ is a monic polynomial of degree $n$ , then which are correct?

Suppose that $P$ is a monic polynomial of degree $n$ in one variable with real coefficients and $K$ is a real number. Then which of the following statements are necessarily correct ?         If $n$ is even and $K>0$ then there exists $x_0\in \mathbb R$ such that $P(x_0)=Ke^{x_0}$.   If $n$ is odd and $K<0$ , then there exists $x_0 \in \mathbb{R}$ such that $P(x_0)=Ke^{x_0}$.   For any natural number $n$, and $0<K<1$ then there exists $x_0 \in \mathbb{R}$ such that $P(x_0)=Ke^{x_0}$.   If $n$ is odd and $K \in \mathbb R$ , then there exists $x_0 \in \mathbb{R}$ such that $P(x_0)=Ke^{x_0}$.      For (3), consider, $P(x)=x^2+5$. Then , there does not exist $x_0\in \mathbb R$ such that $0<e^{-x_0}P(x_0)<1$. So it is FALSE.  But what about the others ?


Mathematically-oriented Treatment of General Relativity

Can someone suggest a textbook that treats general relativity from a rigorous mathematical perspective? Ideally, such a book would   Prove all theorems used. Use modern "mathematical notation" as opposed to "physics notation", especially with respect to linear algebra and differential geometry. Have examples that illustrate both computational and theoretical aspects. Have a range of exercises with varying degrees of difficulty, with answers.   An ideal text would read a lot more like a math book than a physics book and would demand few prerequisites in physics. Bottom line is that I would like a book that provides an axiomatic development of general relativity clearly and with mathematical precision works out the details of the theory.  Addendum (1): I did not intend to start a war over notation. As I said in one of the comments below, I think indicial notation together with the summation convention is very useful. The coordinate-free approach has its uses as well and I see no reason why the two can't peacefully coexist. What I meant by "mathematics notation" vs. "physics notation" is the following: Consider, as an example, one of the leading texts on smooth manifolds, John Lee's Introduction to Smooth Manifolds. I am very accustomed to this notation and it very similar to the notation used by Tu's Introduction to Manifolds, for instance, and other popular texts on differential geometry. On the other hand, take Frankel's Geometry of Physics. Now, this is a nice book but it is very difficult for me to follow it because 1) Lack of proofs and 2)the notation does not agree with other math texts that I'm accustomed to. Of course, there are commonalities but enough is different that I find it really annoying to try to translate between the two...  Addendum (2):  For the benefit of future readers, In addition to suggestions below, I have found another text that also closely-aligns with the criteria I stated above. It is, Spacetime: Foundations of General Relativity and Differential Geometry by Marcus Kriele. The author begins by discussing affine geometry, analysis on manifolds, multilinear algebra and other underpinnings and leads into general relativity at roughly the midpoint of the text. The notation is also fairly consistent with the books on differential geometry I mentioned above.


Proving this inequality by mathematical induction

I want to prove this inequality:   $$ \sum\limits_{i=1}^{2^n} \frac{1}{i} \geq 1 + \frac{n}{2}.$$  So, if I suppose that the inequality holds for a natural number $k$, then   $$ \sum\limits_{i=1}^{2^{k+1}} \frac{1}{i} = {\sum\limits_{i=1}^{2^k} \frac{1}{i}} +  {\sum\limits_{i=2^{k}+1}^{2^{k+1}} \frac{1}{i}}.$$   Thus, I just have to prove that $\sum\limits_{i=2^{k}+1}^{2^{k+1}} \frac{1}{i} \geq \frac{1}{2}$, but I'm stuck on this. I know there are $2^{k}$ natural numbers bewteen $2^k$ and $2^{k+1}$, but I'm not sure how to use it . I'd appreciate your help.


Does the Keywarden in Act 4 randomly drop keys?

I was hunting for the infernal machine plans in act 4, and instead of dropping the plans the keywarden dropped the key of hate. I was on monster level 2 I, don't think that matters, just wondering if the final keywarden can drop keys randomly to save time when hunting for keys in the future?


what is the difference between "going to" and "will"?

what is the main difference between going to and will.  Why we use going to when will is of the same meaning?


How to change the hostname of a RHEL-based distro?

I logged in for the first time, opened terminal, and typed in ‘hostname’. It returned ‘localhost.localdomain.com’. Then I logged as the root user in terminal using the command, ‘su –‘, provided the password for the root user and used the command ‘hostname etest’ where etest is the hostname I’d like my machine to have. To test if I got my hostname changed correctly, I typed ‘hostname’ again at terminal and it returned etest.  However, when I restart my machine, the hostname reverts back to ‘localhost.localdomain.com’.   Here are the entire series of commands I used in terminal.        [thomasm@localhost ~]$ hostname       localhost.localdomain       [thomasm@localhost ~]$ su -       Password:        [root@localhost ~]# hostname etest       [root@localhost ~]# hostname       etest   I had run into the same problem when I set up RHEL and Ubuntu OS’s with VMPlayer.


Does evolution select against genetic diversity?

Only the best genotype in a species will win. So it sounds like evolution selects against genetic diversity.


Is it safe, or even possible, to draw more power from a USB port than it was designed to provide

One of the products being shown a CES is a  intended to let you charge a tablet from a laptop USB port that normally wouldn't work because it didn't provide enough power.  The CNET writeup implies that it's actually boosting the power output from the port beyond the normally available amount.  This seems improbable to me because the ports should have current protection to protect themselves from shorts.  Also, if it was possible to bypass the current limit externally, I'd've expected at least some tablet vendors to have included the ability to do so directly in their cables.  One possibility that occurs to me is that the dongle is just spoofing responses to the tablet when it queries the laptop about the maximum power it can deliver while only providing a trickle charge that the tablet would otherwise reject as too slow to bother with.


I couldn't post this question as it said add more details your post is mostly code. How to fix it?

connection to database file contains:      $server="localhost";     $login="root";     $pass="";     $database="floweritem";      $con=mysqli_connect($server,$login,$pass,$database);     if(mysqli_connect_errno()){     echo "Failed connect to MYSQL".mysqli_connect_error();     }  PHP      <?php     if(isset($_POST['submit'])){     $Name=mysqli_real_escape_string($con,$_POST['Name']);     $Desc=mysqli_real_escape_string($con,$_POST['Desc']);     $Size=mysqli_real_escape_string($con,$_POST['Size']);     $Price=mysqli_real_escape_string($con,$_POST['Price']);       //no problwm with connection to table or database     $sql="INSERT INTO `items`(`Name`,`Description`,`Size`,`Price`)      VALUES($Name,$Desc,$Size,$Price)";     echo $Desc;       if(mysqli_query($con,$sql)){      echo "new record";     }     //always get wrong     //can't find problem     else{echo"Wrong";}     mysqli_close($con);     }     ?>  shows $Desc And then Wrong


Let $n = p_1^{a_1}p_2^{a_2} \dots p_k^{a_k}$. Show that $d(n) = (a_1+1)(a_2+1)\dots(a_k+1).$  How should I go about this? I tried to first show that the divisor function is multiplicative and use that result to prove the statement, but it seems that the multiplicativity depends on the result I'm actually trying to show? Any hints would be appreciated.


I need to use a large software package (Xojo) that requires the 32-bit architecture to run. Try as I might, I can't seem to install the 32-bit libraries on my 64-bit installation of 15.04.  I don't have a problem running a 32-bit version of Ubuntu (I'm only using this computer for Xojo) but the computer has 8GB of RAM and I'd like to be able to use it all. Is there a way to utilise all 8GB of RAM with a 32-bit Ubuntu install? Does Ubuntu do this out of the box?


When I execute ps ax command with grep, it' showing a single entry of test.py  test.py was just single print statement submitted like this:    nohup python test.py &    So I'm assuming it didn't take long to run. Should that entry still be there?    $ ps ax | grep test.py 18225 pts/0    S+     0:00 grep test.py


Numerability on subset of $\mathbb{R}$ with induced topology

A friend of mine has this statement, that I cannot establish wether it is true or false.  Let us consider $\mathbb{R}$ with the euclidean topology. Let us consider $A \subset \mathbb{R}$ such as the topology induced on it is the discrete topology, so $A$ is numerable.  Actually he states that the statement holds whenever $A$ is closed, but I ignore his proof.   I tried to demonstrate, recreating something like the Cantor set, that it is false proved that there exists a non separable set $A$ with that induced topology, but I cannot prove the existence of such $A$.  With discrete topology I mean that for every $x \in A$ there exists an open neighborhood of $x$, that I'll call $I(x)$ such that $I(x) \cap A = {x} $.  Any suggestions?


Prove that if derivative of a holomorphic function is non-zero, then it is locally univalent

Let $f$ be a non-constant entire function such that $f'(z)≠ 0$. Then $f$ is locally univalent.


I have the following statement to prove but not sure how to get started :  Let f: A → B and g: B → A be arbitrary functions. Show that there are subsets A1, A2 ⊆ A and B1, B2 ⊆ B such that : A1 ∪ A2 = A, A1 ∩ A2 = ∅ and B1 ∪ B2 = B, B1 ∩ B2 = ∅ and f(A1) = B1, g(B2) = A2.  I believe we need to use the notion of partial order here.  Thanks for your help.


Minecraft: Mac -> Windows won't connect; Windows -> Mac will. Why?

Any time I try to log in to an open lan world I am now unable to. It was very hit and miss in 1.16 and all the 1.17 snapshots simply do not allow multiplayer between Windows and Mac. I can see the lan world which is running on the windows 10 machine from the mac launcher.  but trying to connect to it times out  no amount of rebooting works. The mac can PING the windows machine happily. The launch arguments are -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M -Djava.net.preferIPv4Stack=true the windows 10 machine is stock standard. no third party firewalls or antivirus has been installed. No special lan settings have been changed other than when installing the wifi dongle on it I selected that it was connected to a home network. That's it. If I HOST the game on the mac, the Windows machine will NEVER see it on the lan via the launcher. I have to edit in and put in the IP address and PORT. The WINDOWS machine is able to join a game hosted on the MAC. The MAC machine is unable to join a game hosted on WINDOWS. What else can I try, since I want the WINDOWS machine to be the server? /edit For those who asked, here are the specs and more details. Mac Specs: MBP 2015 Running Mojave, 16GB ram, AMD Radeon R9 M370X 2 GB. PC Specs: AMD FX 4200, AMD Radeon 580 8Gb, 16GB ram. I have checked:  that the IP address of the windows machine is correct. I used ipconfig at the command prompt to get the IP address and pinged it from the mac. This is fine. I got a windows laptop (windows 7) and put the Minecraft client on it, logged on with my account, and it was able to connect to the PC server no worries and without bringing up any firewall messages or anything. The problem occurs connect mac->widows. The problem does not occur windows->mac or windows->windows The error code is not mentioned on the  thread Other types of connection from the mac to windows work just fine on the same lan.


Enabling model tool even if field already exists using ArcMap ModelBuilder?

I made a quick little tool in ModelBuilder to add specific fields based on a precondition (checked boxes). The issue I'm having is that if any of those fields already exist in the feature I'm trying to add fields too, the tool won't run. Sometimes some of the fields already exist in a feature, and I'm wanting to just add the missing ones. I could delete the existing fields, but then I would lose the data in those fields.  I've found info on a If-Field-Exists logical tool, but I can't seem to find it within Model Builder.   Is this a tool found only in ArcGIS Pro?


Too Many Boot Options On Grub Boot Loader

I have a dual boot windows 10 and Ubuntu on my system and on  grub I am getting some unwanted boot listings.  I want only my windows and Ubuntu boot options on my grub and remove the unwanted efi boot files. How can I?   I cannot upload screenshot of my PC as I don't have 10 reputation to do so. :P


I've got something really weird.  Here is MWE:  \documentclass[a4paper,oneside]{book} \usepackage[english,russian]{babel} \usepackage{inputenc} \usepackage{listings}  \usepackage{fontspec} % fonts \setmonofont{Droid Sans Mono}  \lstset{     basicstyle=\ttfamily\small,     columns=fullflexible,keepspaces,     inputencoding=utf8 }  \begin{document}  \begin{lstlisting} ; sign-extend input 32-bit value to 64-bit ; расширить входное 32-битное значение до 64-битного ; (shift is arithmetical) ; (арифметический сдвиг) \end{lstlisting}  \end{document}   The file is encoded in UTF-8 encoding. Here is russian text interleaved with english. I'm running xelatex test.tex and here is PDF screenshot I've got:    As you may see, english text is fine, but as for russian one, numbers 32 and 64 are somewhat swapped at second line and also left bracket is at wrong position at line 4.   But why?  I've tried to move the text into external file and include it with \lstinputlisting, but result is the same.


What would happen if someone tried to summon a very large object?

I remember something in The Deathly Hallows that Harry tries "Accio Hagrid" and the bike shoots towards Hagrid instead of the opposite thing that should occur. (Thanks Himarm for the quote)     “Hagrid!” Harry called, holding on to the bike for dear life. “Hagrid — Accio Hagrid!” The motorbike sped up, sucked toward the earth.    So what would happen if we said, let's say "Accio Eiffel tower" (Not Accio moon as it may cause death due to various factors :D ), assuming that we don't have enough power to summon such a big object. (I doubt only Dumbledore could manage that! ). Would we get sucked towards Eiffel tower as harry and the bike gets towards Hagrid. Wouldn't that then be a great way to travel? ( If we can somehow manage to prevent collisions, by putting some spell on ourselves or something?)


Vampire spawn and the nature of their "rest"

Vampire spawn have the trait "chained to the grave" which includes the phase "Every vampire remains bound to its coffin, crypt, or grave site, where it must rest by day." Vampire spawn also have the flaw, "Stake to the Heart. The vampire is destroyed if a piercing weapon made of wood is driven into its heart while it is incapacitated in its resting place."  True vampires are merely paralyzed by such an attack, and no mention is made of them being incapacitated while resting.  What does "must rest" by day mean?  Are vampire spawn not allowed to be out of their grave sites in the day?  Could they choose to be up and about (subject to the rules of damage in sunlight) with the only penalty being that they are forgoing rest, or are they rules-required to be in their grave sites?  Can they break their rest and wake up if damaged during the day, or if they hear something with Passive Perception per the optional rules for sleep? [Note that while this question is similar to ], it is not the same, in that it specifically asks about vampire spawn.  The higher voted of the two responses in the other question references Mordenkainen's Tome of Foes, saying that vampires that cannot rest become vampiric mist.  But I am asking about vampire spawn, which do not have access to a true vampire's misty step ability.]  Does the state of "rest" that vampire spawn are in also incapacitate them, in the same way that an unconscious PC is incapacitated?  Or must characters find some way independent of it being day to incapacitate them in order for the stake to instantly kill them?  That is, is the incapacitation a result of the forced rest in the day, or an independent requirement in order to destroy them?


Since the notions of products (resp. sums) of numbers include a convention for the product (resp. sum) of 0 terms, ${\prod_{i \in \emptyset} i = 1}$ and ${\sum_{i \in \emptyset} i = 0}$, I was wondering if there was such a convention for the cartesian product of 0 sets: ${\prod_{i \in \emptyset} A_i = ?}$, where the terms $A_i$ are sets.  Intuitively I would imagine that such a product is equal to the singelton containing the empty tuple {()} since an n-fold cartesian products produces a set of n-tuples and the empty tuple is the only 0-tuple. I'm not sure, however, since I wasn't able to find an answer by searching on the internet or the math stack exchange.


After finishing the "A Refreshing Rescue" Quest, Bottle & Cappy started visiting my Vault. What are their effects, other than the happiness boost? And how does the happiness boost behave?


I need to take a look at all the headers of certain requests. I've been reading the haproxy manual, I am able to use capture to log whatever header I KNOW is there.  But I would like to see ALL the headers, unknown to me, that the app receives. Is this possible with haproxy's logging options? Some sort of regexp or iteration method?  I am using haproxy 1.6  Thank you.


What is the reason for occurence of introns in eukaryotic mRNA?

After transcription of the Template strand of DNA, in prokaryotes, the translation process begins immediately. But in eukaryotes the mRNA transcript has both non coding (introns) as well as coding (exons) sequences. So they undergo Post Transcriptional processes i.e. Splicing, Capping and Tailing.  From where do non-coding sequences arise in eukaryotic mRNA? I'm guessing its from Heterochromatin (found only in eukaryotes). Is this correct?  Also the process in prokaryotes seems to be hassle-free and simultaneous. But what is the reason for such a complicated process in the more evolved eukaryotes?


Compute $\int_{-\infty}^{+\infty} \frac{\sin(x)^k}{x^k} \, dx$ for arbitrary $k > 1$

I want to compute the following integral for an arbitrary $k \in \mathbb{N}$.  $$ \int_{-\infty}^{+\infty} \frac{\sin^k(x)}{x^k} dx$$  For $k = 2$ I computed:   $$ \int_{-\infty}^{+\infty} \frac{\sin^2(x)}{x^2} \, dx = $$  $$ \lim_{n\rightarrow\infty} \int_{-\frac{n\pi}{2}}^{+\frac{n\pi}{2}} \frac{\sin^2(x)}{x^2} \, dx = $$  (Substitute $x = \frac{nt}{2}$)  $$\lim_{n\rightarrow\infty} \int_{-\pi}^{\pi} \frac{\sin^2(\frac{nt}{2})}{(\frac{nt}{2})^2} \frac{n}{2} \, dt = $$  $$\lim_{n\rightarrow\infty} \int_{-\pi}^\pi \frac{2\sin^2(\frac{nt}{2})}{nt^2} \, dt = $$  $$\lim_{n\rightarrow\infty} \frac{1}{2\pi} \int_{-\pi}^\pi \frac{\pi\sin^2(\frac{t}{2})}{(\frac{t}{2})^2} \frac{1}{n} \left( \frac{\sin(\frac{nt}{2})}{\sin(\frac{t}{2})}\right)^2 \, dt = $$  $$\frac{f( 0^{+})- f(0^{-})}{2} = \pi$$  (where $\lim_{t\rightarrow0}\frac{\pi\sin^{2}(\frac{t}{2})}{(\frac{t}{2})^{2}} = \pi$ and $\frac{1}{n} (\frac{\sin(\frac{nt}{2})}{\sin(\frac{t}{2})})^{2}$ represents the Fourier-kernel)  Now for an arbitrary $k \in \mathbb{N}_{\geq3}$ I have tried to use the recursion formula for the sine, but I did not get very far.   I would appreciate any help or ideas!


I have the Facebook app installed on my Android 7 phone.   Auto-update is disabled for all applications on my Play Store account I have disabled installation from unknown sources   For some reason, whenever there is an update of the Facebook app, it automatically updates itself even though I disabled auto-updates for all applications.  How to stop the Facebook app from updating itself automatically?


How to measure code performance in .NET?

I'm doing some real quick and dirty benchmarking on a single line of C# code using DateTime:  long lStart = DateTime.Now.Ticks; // do something long lFinish = DateTime.Now.Ticks;   The problem is in the results:   Start Time [633679466564559902] Finish Time [633679466564559902]  Start Time [633679466564569917] Finish Time [633679466564569917]  Start Time [633679466564579932] Finish Time [633679466564579932]   ...and so on.  Given that the start and finish times are identical, Ticks is obviously not granular enough.  So, how can I better measure performance?


Is there a macro telling which OS we're using?

I got some LaTeX documents that I have to compile them under different TeX Live, such as MacTeX or TeX Live. But in different OS, the font seems different too, for example, while in Windows, I prefer to use Cambria, but in Mac, I like Lucida Grande more.  Is there was a macro to differentiate between OS?    Answer Update  As the accepted answer, We need to add more comments on this question, As I read the , we need more settings to use these macros:  % packages we need \usepackage{pdftexcmds} \usepackage{catchfile} \usepackage{ifluatex} \usepackage{ifplatform}   Then we use these macros like that  \ifwindows % add settings \fi \iflinux % add settings \fi \ifmacosx % add settings \fi % This needs to be \fi, not \if   now, it works well, the point is you need more packages not only ifplatform.  one more thing, compile your tex file with option -shell-escape is required:  xelatex -shell-escape file.tex


I am getting multiple errors for using split within an equation.  I use this command in a number of other places throughout my LaTeX document, but there is one case in which many errors are given saying either:  missing } inserted, \end{split} missing \right, inserted \end{split} extra }, or forgotten \right \end{split}   etc..   There is 12 total errors, some of which repeat, all for this one \end{split} occasion.  MWE:  \documentclass{article} \usepackage{amsmath}  \begin{document}   \begin{equation} \begin{split} \label{eq:FullRate}         W_{full} = \dfrac{2\omega}{9\pi}\left(\dfrac{\sqrt{1+\gamma^2}}{\gamma}\dfrac{m_e\omega}{\hbar}\right)^{3/2}Q\left(\gamma,\dfrac{E_g^*}{\hbar\omega}\right)\:\times\:exp\left\lbrace-\pi\left(\dfrac{E_g^*}{\hbar\omega}+1\right) \\ \times\:\left[K\left(\dfrac{\gamma}{\sqrt{1+\gamma^2}}\right)-E\left(\dfrac{\gamma}{\sqrt{1+\gamma^2}}\right)\right]/E\left(\dfrac{1}{\sqrt{1+\gamma^2}}\right)\right\rbrace \end{split} \end{equation}  \end{document}   I apologize for the lengthy equation.  Everything compiles normally without the split command inserted.  Any ideas why this is causing an error?  I've looked through it a hundred times trying to figure out if I left something out but everything seems to be in the right place.  Thank you for any and all help!


Let $R=\mathbb{Z}[i]=\{a+bi\mid a,b\in\mathbb{Z}\}$, where $i^2 =−1$, and let $I=(3+i)$. Find the exact number of elements in $R/I$.   I know that all element can be written as a real number reminder but does that just mean there is only $0$, $1$, and $2$. But if we take $1+i$ this is equivalent to $-2$ but surely this would go on forever.


How can we know that all of the results for entangled photons are not chosen when the pair is created?

I was reading  introduction to quantum computing that says that when one photon in a pair of entangled photon is measured, the other one will have the opposite result when measured in the same way. But how do we know that all the responses for all the possible measures are not decided for each qubit when the pair is created?   The first photon of the entangled pair would have a surface of half a sphere for which measurements give a positive result, and the other photon would have the other half of the sphere. If you measure both photons on the same axis, then they will never give the same result, as it's impossible for a single point to be in the two halves of the sphere at once, but as you increase the distance between the axes of measurment, the probability for one point to be in the top half of the sphere and the second in the bottom half of the sphere increases.


I have following content in a file. $ cat file.txt code-coverage-api  jsch  cloudbees-folder  apache-httpcomponents-client-4-api  apache-httpcomponents-client-4-api  jsch  apache-httpcomponents-client-4-api  jsch  apache-httpcomponents-client-4-api  jackson2-api  apache-httpcomponents-client-4-api  workflow-api  echarts-api  workflow-api  envinject-api  workflow-durable-task-step  apache-httpcomponents-client-4-api   My expected output is: code-coverage-api  jsch  cloudbees-folder  apache-httpcomponents-client-4-api   jackson2-api  workflow-api  echarts-api  envinject-api  workflow-durable-task-step   At the moment, I am sorting the content like below and then removing the duplicates (except one element) by hand. $ cat file.txt |sort  Is there a way to keep only one duplicate element in the file and remove the remaining duplicate elements from the list? also, keep in mind that there are some elements which don't have any duplicates.


Cosmic Inflation and the Distance between an Electron(s) and Their Respective Nucleus

If cosmic inflation is indeed occurring, doe this apply to all space/time?  What about the space between an electron and the nucleus?  Seems to me if that space is also expanding, atoms should cease to exist.  Or are quantum spaces somehow exempt from inflation?


How do I make a Windows-style cls script for Ubuntu?

How do I make a cls-type command for Ubuntu/Linux that will not only clear the terminal emulator screen, but also make it so you can't scroll up to see the stuff you cleared? Note that the clear command does not eliminate the text. It just scrolls it up out of view. Also, any information about setting it up as a system-wide command, called cls would be helpful (especially nice for Windows users coming to Linux).


Let $G$ be a group. Prove that $o(xy) = o(yx)$ for all $x,y \in G$.  Edit:  I wanted to prove it with basic properties of groups and orders, not with isomorphisms.  I will write the answer I worked on my notebook using the answer by the user that solved my problem (please stop downgrading my question / reputation, I've started learning this 2 days ago by myself, and I believe this site is about helping people to learn):  Let $m = o(xy)$.  Then:  $(xy)^m = e_G$  As $G$ is a group, there exists inverse elements for $x$ and $y$. Let $y^{-1}$ be the inverse of $y$.  As $ye_G = y$, $e_Gy^{-1} = y^{-1}$ and $yy^{-1} = e_G$ we can multiply by $y$ (by the left) and $y^{-1}$ (by the right) obtaining:  $e_G = ye_Gy^{-1}$  Now, as we know that $(xy)^m = e_G$, we can substitute $e_G$ in the previous formula:  $ye_Gy^{-1} = y(xy)^my^{-1}$  Now, we know that $(xy)^m = \overbrace{(xy)(xy)\dots(xy)}^{\text{m times}}$  So, using the previous equation:  $y(xy)^my^{-1} = y\overbrace{(xy)(xy)\dots(xy)}^{\text{m times}}y^{-1}$  And because $G$ is a group, it's associative:  $y\overbrace{(xy)(xy)\dots(xy)}^{\text{m times}}y^{-1} = \overbrace{(yx)(yx)\dots(yx)}^{\text{m times}}yy^{-1}$  And this is:  $(yx)^myy^{-1} = (yx)^me_G = (yx)^m$  So we obtained:  $e_G = (yx)^m$  And as $(xy)^m = e_G = (yx)^m$, $o(yx) = m$, and we conclude:  $o(xy) = o(yx)$ for all $x,y \in G$  I find it interesting solving this kind of problems just by using properties. Using more math structures made the problem trivial.


I have a drive that throws this kind of messages. I'm running 16.04.2 amd64 with the hwe kernel.  I'm searched a bit and I'm not sure what to understand here. Some people are saying that this is not a drive issue, some other are. How can I check that my drive is in a good state for sure considering this error?  [31919.519017] ata4.00: exception Emask 0x10 SAct 0x200 SErr 0x400100 action 0x6 frozen [31919.519036] ata4.00: irq_stat 0x08000000, interface fatal error [31919.519048] ata4: SError: { UnrecovData Handshk } [31919.519058] ata4.00: failed command: WRITE FPDMA QUEUED [31919.519069] ata4.00: cmd 61/00:48:50:fc:70/01:00:08:00:00/40 tag 9 ncq dma  131072 out                     res 40/00:48:50:fc:70/00:00:08:00:00/40 Emask 0x10 (ATA bus error) [31919.519095] ata4.00: status: { DRDY } [31919.519104] ata4: hard resetting link [31919.861466] ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [31919.861975] ACPI Error: [DSSP] Namespace lookup failure, AE_NOT_FOUND (20160930/psargs-359) [31919.862009] ACPI Error: Method parse/execution failed         [\_SB.PCI0.SAT0.PRT3._GTF] (Node ffff8d12be536e88), AE_NOT_FOUND (20160930/psparse-543) [31919.862241] ACPI Error: [DSSP] Namespace lookup failure, AE_NOT_FOUND (20160930/psargs-359) [31919.862259] ACPI Error: Method parse/execution failed [\_SB.PCI0.SAT0.PRT3._GTF] (Node ffff8d12be536e88), AE_NOT_FOUND (20160930/psparse-543) [31919.862331] ata4.00: configured for UDMA/133 [31919.862338] sd 4:0:0:0: [sdl] tag#9 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [31919.862339] sd 4:0:0:0: [sdl] tag#9 Sense Key : Illegal Request [current] [31919.862340] sd 4:0:0:0: [sdl] tag#9 Add. Sense: Unaligned write command [31919.862341] sd 4:0:0:0: [sdl] tag#9 CDB: Write(10) 2a 00 08 70 fc 50 00 01 00 00 [31919.862341] blk_update_request: I/O error, dev sdl, sector 141622352 [31919.862361] ata4: EH complete


Coordinating conjunction immediately followed by parenthetical — Is a comma needed or not?

states:     If a dependent clause, or an introductory phrase requiring to be set off by a comma, precedes the second independent clause, no comma is needed after the conjunction.   Strunk's example illustrates the point:     The situation is perilous, but if we are prepared to act promptly, there is still one chance of escape.   However, I would be tempted to put a comma after the "but," like this:     The situation is perilous, but, if we are prepared to act promptly, there is still one chance of escape.   So, I know you're thinking, "Well, Strunk's Rules of Usage says that you're wrong. No comma."   But is Rules of Usage really the best source? I'd like to see this rule in a more contemporary and authoritative source, like the Chicago Manual of Style.  There are many instances —  — where the comma is included before a parenthetical comment that comes after a coordinating conjunction.  Any authoritative source on the issue?


Bosch 400Wh battery first led only is flashing and refuses to charge

On a long trip with a lot of wind my 400Wh battery went empty.When i tried to charge it at home it refuses to charge. The first of the five leds is flashing. Strange because in the manual is written 1,3,5 leds or 2,4 there is nothing about only the fisrt one. Any suggestions?


Trying to rent car in USA for more than 30 days

We want to rent a car in Las Vegas in February, travel across California and Arizona, then return it to Las Vegas approximately 35 days later. When I check car rentals it shows that at the 30 day mark we have to return to Vegas to have it checked then rent again. This doesn't work for us since we won't be anywhere near Las Vegas at the 30 day mark.   Does anyone know a company that lets you rent for 35 days, without having to go back to rental location at the thirty day mark?


While deploying war file in weblogic 10.3.6 im getting below error

Hi while deploying war file in weblogic server 10.3.6 im getting the below error  java.lang.NoSuchMethodError: org.springframework.beans.MutablePropertyValues.add(Ljava/lang/String;Ljava/lang/Object;)Lorg/springframework/beans/MutablePropertyValues;  Do u know how this error is related??? im using 4.3.4.RELEASE      <dependency>                 <groupId>org.springframework</groupId>                 <artifactId>spring-core</artifactId>                 <version>${spring.version}</version>                 <scope>compile</scope>             </dependency>             <dependency>                 <groupId>org.springframework</groupId>                 <artifactId>spring-web</artifactId>                 <version>${spring.version}</version>                 <scope>compile</scope>             </dependency>             <dependency>                 <groupId>org.springframework</groupId>                 <artifactId>spring-jdbc</artifactId>                 <version>${spring.version}</version>             </dependency>             <dependency>                 <groupId>org.springframework</groupId>                 <artifactId>spring-tx</artifactId>                 <version>${spring.version}</version>             </dependency>             <dependency>                 <groupId>org.springframework</groupId>                 <artifactId>spring-webmvc</artifactId>                 <version>${spring.version}</version>             </dependency>   <dependency>                 <groupId>org.springframework.data</groupId>                 <artifactId>spring-data-oracle</artifactId>                 <version>1.2.1.RELEASE</version>             </dependency>   is it related to web-servlet.xml?? here is my web-servelt.xml  <beans xmlns="http://www.springframework.org/schema/beans"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"     xmlns:context="http://www.springframework.org/schema/context"     xmlns:jee="http://www.springframework.org/schema/jee" xmlns:mvc="http://www.springframework.org/schema/mvc"     xmlns:tx="http://www.springframework.org/schema/tx" xmlns:task="http://www.springframework.org/schema/task"     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd          http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd          http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd         http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.0.xsd         http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd ">


What are the two math symbols here and how to get them in Latex?

I have been trying in vain to get the names for the below two math symbols and how to use them in Latex. Anyone who could help me please?    Thanks.


The origin of the word "Pink" ....what more can I add to this simple question?

How specifically did the word "pink" derive?


Non detection 3G/4G mu736 huawei card at ini

Why always my Kubuntu non detect my 3G/4G Card? Always, when I turn on my computer, I need to do this steps to turn on the 3G/4G Integrated card mu736 huawei - model [  The steps that I need to follow in the Konsole are:  ALL ALL= NOPASSWD: /home/victorsnk modprobe option echo "03f0 521d" > /sys/bus/usb-serial/drivers/option1/new_id usb_modeswitch -H -v 03f0 -p 521d -s 10   the result thrown is:  victorsnk@victorsnk-HP:~$ sudo su [sudo] password for victorsnk:  root@victorsnk-HP:/home/victorsnk# cd script root@victorsnk-HP:/home/victorsnk/script# ./modem.sh ./modem.sh: línea 3: ALL: orden no encontrada Note: No target parameter given; success check limited Look for default devices ...    product ID matched  Found devices in default mode (1) Access device 002 on bus 002 Current configuration number is 1 Use interface number 0  USB description data (for identification) ------------------------- Manufacturer: Hewlett-Packard      Product: HP hs3110 HSPA+ Mobile Broadband Device   Serial No.: not provided ------------------------- Send old Huawei control message ...  Check for mode switch (max. 10 times, once per second) ...  Wait for original device to vanish ...  Original device can't be accessed anymore. Good.  (For a better success check provide target IDs or class)  Original device vanished after switching  Mode switch most likely succeeded. Bye!   *Note: I had to created a script to resume the process, but I can't get start it at the ini when I start the computer. Anybody knows how can I solve it?  My OS is Kubuntu 16.4 LTS (64x) and my kernel 4.14.0-041400-generic  Thanks!


How can I batch download a set of pdfs from a course webpage?

I often need to download sets of links from a webpage and it's very inefficient having to click all the links one by one. For example, at the moment I want to download the lecture notes on  webpage. Is there some way I can batch download them? I am using Linux and Firefox in case that information is useful


Why is “I have learnt English since 2 years” incorrect?

Or maybe better phrased as “I have been learning English since 2 years”. I took the example sentence from . From Dan’s answer I learnt that “learnt” is not short for “been learning”. It is interesting that it is used as an example of a correct sentence on the linked page.  The sentence should be “I have been learning English for 2 years”. As a native English speaker without an in depth understanding of how grammar rules work beyond “it doesn’t sound right”, I was wondering if there is an easy to understand explanation for what (and how) grammar rules should be applied when differentiating between “for” and “since” to describe how long something has been happening. I think StoneyB's answer to  largely answers this but I would like to know a little more about what the present perfect is and how it relates to this sentence construction.  As I seem to frequently encounter this confusion with ESL speakers, I was wondering is this a peculiarity of the English language that makes it difficult to translate? Is the grammar differences caused by the lack of a conceptual difference between “for” and “since” in other languages rather than just choosing the wrong dictionary word? If so, what is the best way to explain this?


Is it harmful to the human body if we don't turn off the light completely while sleeping?

While sleeping, some people may leave the light on or dim it down, so that perhaps it is equal to a 35W or 20W regular light bulb.  In this case, is it true that the pineal gland in our brain won't secrete melatonin during the sleep, and therefore have harmful effects to the human body?  What if we occasionally cover our body and even the head temporarily using the quilt during our sleep, so that there is close to no light that gets to our skin (as it is said that even light on the skin can affect the pineal gland to not secrete melatonin).  There are some variations to this, and I wonder if it is similar:   If there is a street light or community light post outside of the window, so throughout the night there is as if a 10W or 20W light bulb inside the room. If the light in the room is turned off, but the hallway has a ceiling light and it is on, while the bedroom door is about 80% closed but some light in the hallway can come in. Some people may leave the TV on (and possibly turning the volume to quite low) while sleeping. It is said that blue light might have the biggest effect out of the light spectrum on our pineal gland to not secrete melatonin, as most electronic devices do, such as a smartphone screen or LCD/LED TV screen). So if we turn off the light but leave the TV on, then it might still be the same issue or even more so.


Can users delete their chat account after deleting all their other accounts?

I noticed a former mod who  still has their  (emphasis mine):  My diamond how now been removed and I have scheduled the deletion of all of my accounts across the network. Whatever the interpretation for my action, this wasn't done out a sense of pettiness, attention-seeking, or of protesting against Stack Exchange. This is my protection from the self-harm that seems to be endemic in the community right now.  As much as I support Monica and despise the way in which she was deposed, there is seemingly no end to the amount of conflict that this situation and the events around it has plunged the community into.  When looking for dupes, I found that that's a quirk of the system, :  The root problem is that when a chat user's parent account gets deleted, the chat account doesn't get reparented. We should fix that, and delete the chat account only when there is no remaining account on that user's network profile that is relevant to the chat server in question.  Now, I'm wondering if it's actually possible to delete a chat account after deleting all accounts on SE sites in the network. After all, you can no longer simply sign in on an SE network account and delete your chat account. How does that work? Or is this a non-issue because (not saying that it is) there is no personal information associated with the chat account. How does this work?  Sonic commented a . That appears to say that the issue in the quote is fixed, that the chat account should be deleted when all users are deleted. That doesn't appear to be the case here, is that a bug?


Hello fellow lens loving junkies! I have been struggling to get very sharp, non-grainy images. I have a Canon Rebel Eos T3i. Even images at 100 ISO are not as sharp as I would like. Not sure if it is just that my camera is a 12 megapixel, or not. I have been struggling for months now to get the extreme detail and high resolution I want. I have been considering a camera base upgrade to Canon 70D, but wanted to ask if there was anything else I should consider first. I really struggle in low light conditions, even with a f/1.8 lens on. Images appear almost blotchy and/or grainy, plus the depth of field is extremely short with that lens. My camera has been exposed repeatedly to -40 degree weather, due to cold weather shoots I do during the winter, not sure if that would affect the sensors or not. Thanks!


To prove that $ [n/1]+ [n/2]+[n/3]+\dots +[n/n]+[\sqrt{n}]$ is even.

Let $n$ be a natural number. How do you prove that   $$ \lfloor n/1 \rfloor+ \lfloor n/2\rfloor+ \lfloor n/3\rfloor+\dots +\lfloor n/n]+\lfloor \sqrt{n}\rfloor$$  is even? Thanks.


My phone shows no Pokemon but other people around me are finding them

I am playing on an iPhone 6s and recently I was in a highly populated area with lots of people playing. I had Wi-Fi on and GPS was working, but my phone was not showing that I had any nearby.  I talked with some young men who told me there were at least 9 nearby.  Why wasn't my phone showing them?


Help proving the product of any four consecutive integers is one less than a perfect square

Apparently this is a true statement, but I cannot figure out how to prove this. I have tried setting   $$(m)(m + 1)(m + 2)(m + 3) = (m + 4)^2 - 1 $$  but to no avail. Could someone point me in the right direction?


sorting filenames numerically when they have non-numeric prefix

I have files in the following format: x1 x2 ... x10 x11 ... x101 ...  I want to rename these files, so they all have the same name length: x001 x002 ... x010 ...  I can do this with files, that don't have the non-numeric prefix (just using sort -n followed by a while read x;), but sort doesn't recognize the numeric value, when it's not on the beginning of the file-name.


Assigning Z values (in attribute table) to shapefile geometery

I have polyline data (contour data),  the z value is in the attribute table. The shapefile does not have the z_value set in the geometry. I am able to get point data to work, but when I do the same process, I end up with a midpoint for the line with an xyz value. I need the line data to have a z value before I convert the shapefile (Feature class) to a DWG file for AutoCAD. I use ArcMap (ArcView 10.0) with not extra extensions and QGIS so either software will be fine.


If $\sum a_n b_n <\infty$ for all $(b_n)\in \ell^2$ then $(a_n) \in \ell^2$

I'm trying to prove the following:     If $(a_n)$ is a sequence of positive numbers such that $\sum_{n=1}^\infty a_n b_n<\infty$ for all sequences of positive numbers $(b_n)$ such that $\sum_{n=1}^\infty b_n^2<\infty$, then $\sum_{n=1}^\infty a_n^2 <\infty$.   The context here is functional analysis homework, in the subject of Hilbert spaces.  Here's what I've thought:  Let $f=(a_n)>0$. Then the problem reads: if $\int f\overline{g}<\infty$ for all $g>0,g\in \ell^2$, then $f\in \ell^2$. This brings the problem into the realm of $\ell^p$ spaces.  I know the inner product is defined only in $\ell^2$, but it's sort of like saying: if $\langle f,g\rangle <\infty$ for all $g>0,g\in \ell^2$ then $f\in \ell^2$.  I read this as: "to check a positive sequence is in $\ell^2$, just check its inner product with any positive sequence in $\ell^2$ is finite, then you're done", which I find nice, but I can't prove it :P  From there, I don't know what else to do. I thought of Hölder's inequality which in this context states: $$\sum_{n=1}^\infty a_nb_n \leq \left( \sum_{n=1}^\infty a_n^2 \right)^{1/2} \left( \sum_{n=1}^\infty b_n^2 \right)^{1/2}$$  but it's not useful here.


Why running command as sudo returns command not found?

Sample command:  drush cc all   works, but this:  sudo drush cc all   gives me:  sudo: drush: command not found   Why? How to fix this?


I have a large array of stock ticker symbols, as I am for a project writing a stock market simulation webapp. One of my helper functions is one to determine whether the entered stock is valid by checking the array for the symbol. To do this, I am using array_search(). The problem I have is one by checking edge cases. It seems that the search isn't picking up the 0th element, even though it picks up other elements completely fine. Here is part of the array:  [0] => AAC [1] => AACC [2] => AACOU [3] => AACOW [4] => AAIT [5] => AAME [6] => AAON [7] => AAPL [8] => AAWW [9] => AAXJ [10] => ABAX [11] => ABCB [12] => ABCD [13] => ABCO [14] => ABFS [15] => ABIO [16] => ABMD [17] => ABTL [18] => ABVA [19] => ACAD [20] => ACAS [21] => ACAT [22] => ACCL   Etc, etc. As said before, it works fine for other elements, just not the 0th one. It returns FALSE when searching for AAC.  Here is the PHP code I am using.  <?php                    if(isset($_GET[stock])) {                     $ticker = $_GET[stock];                     $ticker = trim($ticker);                     print("
Ticker is $ticker
");                      print("Validity: " .        Stock::isValidStock($ticker));                      print('
');                     $stock = Stock::getStockList();                     print_r($stock);                     print((bool)array_search('AAC', $stock));                     print('

');                 }             ?>    You can change the stock by editing the query string in the url.  As I said, ?stock=AAC returns false, while something like ?stock=GOOG is true. Thanks for any help!


Does an adjective before "or" apply to the noun that comes after "or"?

Have you come across any frilly dresses or blouses?  Does this mean [frilly dresses or frilly blouses], or does it mean [frilly dresses or blouses]? I want to know whether an adjective so placed only applies to the noun that comes immediately after it, or to the noun that comes after "or", too. Or is there ambiguity here?


Novel with a class of "Lords" with external databank-type neural implants

I need an ID on a (probably young adult) sci-fi novel I don't remember finishing.  I read it sometime in the late nineties or early noughties. The library book didn't show any obvious indications of age that I recall. The book was in Finnish but I think it was a translation. The cover image was a person with long chains of cabled-together cylinders projecting diagonally upward from the back of their neck. It almost looked like they were hooked into something by those.  The main protagonist is a young nobleman, I think the term was "Lord", from a ruling family. This class of nobleman is characterized by having databank neural implants dangling from the back of their neck. These databanks are heavy enough to affect the wearer's posture, and the result was described as a lordly slouch.  The story starts with the main character's coming of age ceremony, where they get the databank implants. There's a scene where the character gets a new set of clothes for the occasion, with his family crest cleverly worked into the decorative patterns by his mother.  After the actual implantation, the ceremony is interrupted by a coup of some sort. The main character has some trouble evading pursuit because he is wearing his family crest prominently. Somehow, he ends up outside the city, which is on some sort of stilts. For whatever reason, he can't return to the city, maybe he locked himself out or he was hiding from the coup.  This results in the character's first experience of being outside. I remember a scene where he's looking at the moon and pulls the hard data on said celestial body from his databanks, and then decides to look up poetry instead.   Some time later, the main character ends up living in a village of outsiders. The last scene I remember is that one night he overhears the men in the village singing about how their people had once been slaves to the Lords. That's where my recollection of the plot ends.  It is not  by Walter John Williams; the story didn't mention splitting one's consciousness, and in the Aristoi setting the databank seems to be "in the cloud" rather than as external add-ons.


Let $x,y \in \mathbb{R}$..Show that $x^{n+1}-y^{n+1}=(x-y) \sum\limits_{k=0}^n x^k y^{n-k}$ for all $n \in \mathbb{N}_0$

Let $x,y \in \mathbb{R}$.   Show that $$ x^{n+1}-y^{n+1}=(x-y)\sum_{k=0}^n x^k y^{n-k} $$  for all $n \in\mathbb{N}_0$  I need to prove this via induction.  My attempt: base case (k=0) = $$x^{0+1}-y^{0+1}=(x-y)(x^0 y^{n-0}) $$                   $$x-y=(x-y)(y^n)$$ Here is where I get lost, does this disprove this? This statement is only true if $y^n = 1$? Doesn't this mean that this isn't true for all $x,y$ in $\mathbb R$?


How to put a Part of my Model into a New File

I'm Newbie and i have a packet of Trees which are packed into one single 3ds file. How can i make seperate models of it? In Photoshop etc, i'd use "Copy&Paste" it into a new File, how is it done in blender, the easiest way?


Show that $F(a) = F(a^{2})$ knowing that $F(a)$ has odd degree.

If $K$ is field extension of $F$ and if $a \in K$ such that $[F(a):F]$ is odd, show that $F(a) = F(a^{2})$. Given an example to show that this can be false if the degree of $F(a)$ over $F$ is even.    I know that $F(a^{2}) \subseteq F(a)$ and $[F(a):F] = [F(a):F(a^{2})][F(a^{2}):F]$. I know too that if $[K:F] = p$ with $p$ prime, so there are no intermediate fields between $K$ and $F$. Any hints?


Formula for the summation of the series $a+2a^2+3a^3+...$ upto nth term?

I need a formula for the summation of the series $a+2a^2+3a^3+...$ upto nth term. Is there any way to simplify it?


I have the plugins which I need but it doesn't play after all. My DVDs are new and I tried more than one and none of them work. I can play self-created DVDs with no problems.  I tried different players like Dragon, VLC, SMPlayer; the ones everyone says are good. I don't doubt it and SMPlayer is good but, you know, no DVDs!   If I try Dragon it displays all black. If I try VLC it jumps from one data to another but it doesn't play. If I try SMPlayer it shows me that it was played... but it didn't play at all.


iphone - hiding UITabBar without presentModalViewController or pushViewController

Hey guys, like the question states, I am trying to slide in a UIDatePicker without using presentModalViewController or pushViewController and subsequently hide the main UITabBar of the application. Right now, I am adding the UIDatePicker subview with a couple buttons on a Navigation Bar to a temporary UIViewController, and initializing a UINavigationController with that temporary controller as the root. I am adding this Navigation Controller as a subview to self.navigationController.tabBarController in an attempt to overlay the UITabBar, but when I set the UITabBar to hidden, all I see is white beneath it, with no UIDatePicker visible. Any suggestions?  Note: My reasoning for this is that I can't figure out a way to use presentModalViewController with a view smaller than the screen.


What is the difference between dexp and pexp

I understand probability distribution but I am having a hard time getting a grasp on probability density function, specifically difference between dexp (density of exponential distribution) and pexp (probability distribution of exponential distribution)


can you help me with this error: Errors were encountered while processing: virtualbox-dkms I installed Oracle Virtualbox and it's working well. $ sudo apt install ./zoom_amd64.deb [sudo] password for louisro:  Reading package lists... Done Building dependency tree        Reading state information... Done Note, selecting 'zoom' instead of './zoom_amd64.deb' The following packages were automatically installed and are no longer required:   kbuild libgsoap-2.8.91 libvncserver1 module-assistant virtualbox-source Use 'sudo apt autoremove' to remove them. The following packages will be upgraded:   zoom 1 upgraded, 0 newly installed, 0 to remove and 6 not upgraded. 1 not fully installed or removed. Need to get 0 B/45,9 MB of archives. After this operation, 85,7 MB disk space will be freed. Get:1 /home/louisro/zoom_amd64.deb zoom amd64 5.4.57862.0110 [45,9 MB] (Reading database ... 266695 files and directories currently installed.) Preparing to unpack /home/louisro/zoom_amd64.deb ... Unpacking zoom (5.4.57862.0110) over (3.5.392530.0421) ... run post uninstall script, action is upgrade ... Setting up virtualbox-dkms (6.1.10-dfsg-1~ubuntu1.20.04.1) ... Removing old virtualbox-6.1.10 DKMS files...  ------------------------------ Deleting module version: 6.1.10 completely from the DKMS tree. ------------------------------ Done. Loading new virtualbox-6.1.10 DKMS files... Building for 5.8.0-36-generic Building initial module for 5.8.0-36-generic ERROR: Cannot create report: [Errno 17] File exists: '/var/crash/virtualbox-dkms .0.crash' Error! Bad return status for module build on kernel: 5.8.0-36-generic (x86_64) Consult /var/lib/dkms/virtualbox/6.1.10/build/make.log for more information. dpkg: error processing package virtualbox-dkms (--configure):  installed virtualbox-dkms package post-installation script subprocess returned  error exit status 10 Setting up zoom (5.4.57862.0110) ... run post install script, action is configure... Error in file "/usr/share/applications/org.kde.kdeconnect_open.desktop": "*/*" i s an invalid MIME type ("*" is an unregistered media type) Processing triggers for mime-support (3.64ubuntu1) ... Processing triggers for gnome-menus (3.36.0-1ubuntu1) ... Processing triggers for shared-mime-info (1.15-1) ... Processing triggers for desktop-file-utils (0.24-1ubuntu3) ... Errors were encountered while processing:  virtualbox-dkms E: Sub-process /usr/bin/dpkg returned an error code (1)


Save a json object but not for reference

here is my problem, reported in a way much more simplified  this is the json (look at the json  if you want)  {"resource":[{"id":"1408694994","obj":[{"id":"1","action":[{"name":"ON","id":"301"},{"name":"OFF","id":"302"}]},{"id":"2","action":[{"name":"ON","id":"303"},{"name":"OFF","id":"304"}]}]},{"id":"1408694995","obj":[{"id":"3","action":[{"name":"ON","id":"305"},{"name":"OFF","id":"306"}]},{"id":"4","action":[{"name":"ON","id":"307"},{"name":"OFF","id":"308"}]}]}]}   Given an id (in this case we say id = 3), I must save the item with that ID. And i save in a new object (newobj) the object with that ID, but changing the array ACTION in an OBJ with the only action ON  Example  <script>       var tt = '{"resource":[{"id":"1408694994","obj":[{"id":"1","action":[{"name":"ON","id":"301"},{"name":"OFF","id":"302"}]},{"id":"2","action":[{"name":"ON","id":"303"},{"name":"OFF","id":"304"}]}]},{"id":"1408694995","obj":[{"id":"3","action":[{"name":"ON","id":"305"},{"name":"OFF","id":"306"}]},{"id":"4","action":[{"name":"ON","id":"307"},{"name":"OFF","id":"308"}]}]}]}';      var myjson = JSON.parse(tt);      var search = 3;       console.log(myjson.resource[1].obj[0]);      for(var i = 0 ; i < myjson.resource.length; i++){          for(j = 0 ; j < myjson.resource[i].obj.length; j++){              if(parseInt(myjson.resource[i].obj[j].id) == search){                  var newobj = myjson.resource[i].obj[j];                  var obj_action = newobj.action;                 for(var k = 0 ; k < obj_action.length ; k++){                      if(obj_action[k].name == "ON"){                         newobj.action = obj_action[k];                     }                 }             }            }     }      console.log(myjson.resource[1].obj[0]);  </script>   I can easily save in the variable newobj the object that i want. But why the initial json is changed ???  UPDATE  ok, I understand that it is clearly problem of how I save the obj in newobj variable. i dont' save the object, but only the reference at the object in json . how can I save it in the variable newobj ? (not by reference?)


Problem regarding Chinese remainder theorem and modulo arithmetic

I've been trying to solve a Chinese remainder theorem problem using modulo arithmetic. The example on  is a case where there is only 3 equations (and therefore 3 unknowns). In the wikipedia example, it seems as though I am expressing the 1st unknown in terms of the 2nd unknown, and then plug this into the 1st equation to get 2 equations (old and new) for the 2nd unknown. Equate equations 2 and 3 to get 3rd unknown in terms of equation 2, then substituting this into the 2nd new equation. I'm sorry if that seems quite confusing, but that's how I feel currently (confused).  In my case, there are 6 unknowns,  (i) $x = 1$ (mod $2$) = $1 + 2.p_{1}$ (mod $2$)   (ii) $x = 2$ (mod $3$) = $2+3.p_{2}$ (mod $3$)   (iii) $x = 3$ (mod $4$) = $3 + 4.p_{3}$ (mod $4$)   (iv) $x = 4$ (mod $5$) = $4+5.p_{4}$ (mod $5$)   (v) $x = 5$ (mod $6$) = $5 + 6.p_{5}$ (mod $6$)   (vi) $x = 0$ (mod $7$) = $7.p_{6}$ (mod $7$)  I have been able to get $x = 5 + 6_p{2}$ (mod $2$), but have been unable progress further. Any pointers in the right direction would be much appreciated! THanks


Unable to modify eclipse.ini file in snap

I have installed eclipse in Ubuntu 18.04 via Snap. And in the snap folder, I can see eclipse, where I want to add few lines in eclipse.ini file, but I'm getting "E45: 'readonly' option is set (add ! to override) " msg , even I'm not able to change file permission.  -rw-rw-r-- 1 root root 586 Apr  5 20:25 /snap/eclipse/12/eclipse.ini