Sharing a pie evenly among an unknown number of people.

This is a question inspired by the question  on the Puzzling Stack Exchange.  Suppose you're throwing a party, and you know that either 7, 8, or 9 people will arrive. Before anyone arrives, you want to cut the pie into the fewest number of pieces such that you can give everyone an equal amount.  In this case, you can cut the pie into 18 pieces of the following sizes (this is conjectured to be the minimal number of pieces).  $$\frac{1}{168}, \frac{1}{72}, \frac{1}{56}, \frac{1}{36}, \frac{2}{63}, \frac{1}{28}, \frac{23}{504}, \frac{1}{21}, \frac{25}{504}, \frac{5}{84}, \frac{31}{504}, \frac{4}{63}, \frac{19}{252}, \frac{5}{63}, \frac{1}{12}, \frac{47}{504}, \frac{7}{72}, \frac{1}{9}$$  Then you can divide this into nine parts:  $$ \left(\frac{1}{168}, \frac{23}{504}, \frac{5}{84}\right),  \left(\frac{1}{72}, \frac{7}{72}\right),  \left(\frac{1}{56}, \frac{47}{504}\right),  \left(\frac{1}{36}, \frac{1}{12}\right),  \left(\frac{2}{63}, \frac{5}{63}\right),  \left(\frac{1}{28}, \frac{19}{252}\right),  \left(\frac{1}{21}, \frac{4}{63}\right),  \left(\frac{25}{504}, \frac{31}{504}\right),  \text{ and } \left(\frac{1}{9}\right). $$  Into eight parts: $$ \left(\frac{1}{168}, \frac{1}{28}, \frac{1}{12}\right), \left(\frac{1}{72}, \frac{1}{9}\right), \left(\frac{1}{56}, \frac{1}{21}, \frac{5}{84}\right), \left(\frac{1}{36}, \frac{7}{72}\right), \left(\frac{2}{63}, \frac{47}{504}\right), \left(\frac{23}{504}, \frac{5}{63}\right), \left(\frac{25}{504}, \frac{19}{252}\right), \text{ and } \left(\frac{31}{504}, \frac{4}{63}\right) $$  And into seven parts: $$ \left(\frac{1}{168}, \frac{1}{72}, \frac{1}{21}, \frac{19}{252}\right),  \left(\frac{1}{56}, \frac{1}{36}, \frac{1}{28}, \frac{31}{504}\right),  \left(\frac{2}{63}, \frac{1}{9}\right),  \left(\frac{23}{504}, \frac{7}{72}\right),  \left(\frac{25}{504}, \frac{47}{504}\right),  \left(\frac{5}{84}, \frac{1}{12}\right),  \text{ and } \left(\frac{4}{63}, \frac{5}{63}\right) $$    The question  I'm interested in an algorithm that can produce such a minimal pie cut. In this case, it would take in the set of the possible numbers of guests, $\{7,8,9\}$, and output the list of fractions above—or a different list of minimal length.  I don't particularly care about the computational complexity of the program.  I am interested in proving that the program outputs the minimal number of "slices".    More examples  $$ \begin{align*}   f(\{2\}) = f(\{1,2\}) &= \left(\frac{1}{2},\frac{1}{2}\right) \\   f(\{n\}) = f(\{1,n\}) &= \underbrace{\left(\frac{1}{n},\frac{1}{n},\cdots,\frac{1}{n}\right)}_n \\   f(\{2,3\}) &= \left(\frac{1}{3},\frac{1}{3},\frac{1}{6},\frac{1}{6}\right) \end{align*} $$


Pushing a custom hyperlink to Google Sheets with Google Apps Script

I'm looking for an easy way to let my code turn a link from regular static text into a hyperlink that can be clicked. The code should let you put in an input of text, and then the code will automatically turn it into a link that lets you use that image search in the Google doodle game, Image Breakout, a spin-off of Atari Breakout.  The first thing I did was try this:  function IMAGEBREAKOUT(input)  { var array = []; var url = 'https://www.google.com/search?q=' + input + '&tbm=isch&tbs=boee:1';   array.push([url]);   return array; }   That only gave me regular text, and did not give me a clickable link, so then I tried this:  function IMAGEBREAKOUT(input)  {   var array = [];   var url = 'https://www.google.com/search?q=' + input + '&tbm=isch&tbs=boee:1';     array.push("" + url + "");     return array; }   But, that only gave me static text with HTML formatting that didn't work. So, then I tried researching, and went on to try this:  function IMAGEBREAKOUT(input)  {  var array = [];  var url = 'https://www.google.com/search?q=' + input + '&tbm=isch&tbs=boee:1';     SpreadsheetApp.getActiveSheet().getActiveCell().setFormula('=HYPERLINK("' + url + )'); }   But it said I didn't have permission to call setFormula.  I tried authorizing the app later, and it worked when running it in the editor, but running the formula in Google Sheets gives me the same error.  I'm in a tight spot here. Can someone help me, or revise my script so that it doesn't require so much? If that's not possible, is there a simpler way to do this that I'm not thinking about? Thanks!


Let $A$ be a nonempty subset of $\mathbb{R}$. Prove...

I'm suppose to prove the following...  Let $A$ be a nonempty subset of $\mathbb{R}$. If $\alpha = \sup A $ is finite show that for each $ \epsilon > 0 $ there is an $a \in A $ such that $\alpha - \epsilon < a\leq \alpha $.  This is what I have so far...  Proof: We claim that $\alpha = \sup A $   Then by definition of a supremum $\alpha $ is the least upper bound of set A  Thus $\forall a \in A$,  $a \leq \alpha$   Suppose $\epsilon > 0$   Then $\alpha - \epsilon < \alpha $.   Thus $\alpha - \epsilon < a\leq \alpha$.   I feel like I'm missing some step between my last and second to last step so what am I forgetting? Also is the rest of my proof right?


Will a 2A 12VDC PSU harm a 3A OnHub wifi Access point?

What's the risk of using PSU that is underpowered? Is there risk to the device drawing the power?  I have a TPLINK AC1900 Onhub Router. It is missing the PSU (12VDC, 3A)  I have a 12VDC 2A. I think the only risk is that I'll blow the PSU ( I guess it might heat up as well. Perhaps dangerously??).  The PSU is a leftover, so I don't mind the risk of blowing it.  But... perhaps there's some risk to the OnHub as well? -Clay


Yesterday my supervisor mounted one of his directories onto my server. The problem is, I can't access them and I have no way of contacting him right now. When I type in the URL I get this error:  Forbidden You don't have permission to access /~<username>/core/ on this server.   I tried to cd into the "core" directory and do the following:  chmod -R 755 *.*   but, even with all the permissions changed, I still can't get access! The weird thing is, I can access and edit the files.


Unattributed Reproduction of S.E. Content

I know that S.E. places a  license on material and I just ran across this:    Which is pretty clearly  edited down a bit, including the removal of names.  There is no indication of the source, or that it is not original material.   Interestingly, at the bottom of the page there's a note:     © 2014 codeitive.com, All rights reserved   user contributions licensed under cc by-sa 3.0 with attribution required.    That site obviously contains a lot of other ripped Stack Overflow material. It seems to me this is a violation of the licence; I am irritated that the stuff I and others work hard on in an explicit CC-SA context is being presented as original material on a site with advertising (i.e., someone else is using it to make money without appropriate attribution).  Am I wrong about the legal issue here?


Renaming Multiple files in different directories

I have about 5TB of data stored on Synology NAS servers with a DSM of 6.1+, so bash should be available for use on these systems. The issue is that we are currently archiving this data to external hard drives formatted for NTFS. The main issue is that during the archiving process there appears to be some file conflicts where Linux is case sensitive but Windows is not. So for example:  Test.txt  test.txt   In linux these are two separate files, but Windows will see them as one file.   The question in hand is that I should be able to figure out which files are conflicts using a tool we used in the past, but there are too many files to rename them manually. These files are spread out across multiple directories going 3 or 4 directories down. If I was able to find out all of the files that are in fact conflicts, what would be the easiest way to rename these files?   The naming really does not matter as long as they do not move from their current location. In the past I have just added a "1" to the end of some of these conflicts, but like I said there are hundreds of conflicts this time.   Are there any recommended tools to find file conflicts like this?


So, I eat a lot of eggs, and I’ve fallen in love with omelettes, but it seems that they want to fall apart. I normally just use eggs, and the stuff I want in there, but I don’t get the restaurant kind of look, or stability of it, I mean it’s just as good, but I’d like to impress a special someone with cooking possibly, and yeah, I don’t want it falling apart. So, I’m curious if I need to be adding something like cream cheese or something to hold it together better. Maybe I can up it from two eggs to three?


Fantasy series with young red-headed female protagonist, past lives, multiple dimensions, elemental magic

I read the book series a long time ago. Hopefully the bits I remember, listed below, are enough to go on.   From memory there are three or four books in the series and I read them in the mid 2000's, in English, and they were pitched at a youth/young adult level though not afraid to tackle some serious issues (fairly sure there is a main character death at some point) The main character was a girl in her teens (name potentially beginning with an 'A' and maybe tied to the name of one of the books and/or the series?) and she had red hair She was human and living in modern times and ended up mixed up in a bunch of conflict in multiple other worlds or dimensions (I think the first time she got dragged into it she had been exploring out the back of her house and there were portals or gateways under the hill) and developed various powers/magic through the books and obviously ended up having to save the world  She ends up having had previous lives and during the series she gets access to the memories from the previous lives  May have been some form of time travel included There were a number of other races in the novels who inhabited the other worlds, and there was elemental magic around There was a floating mountain at some point I think, and dragons


Calculate  $\sum_{k=1}^n (-1)^{k+1} \binom{n}{k}\frac{1}{k}$, I do not know hot get rid of that $k$, for me it is similar like  $\binom{n}{k}=\frac{k}{n} \binom{n-1}{k-1}$, do you have some idea?


Can I transit South Africa if I have a one-year entry ban?

I am a Botswana citizen. In October 2018, I was deemed undesirable by South Africa for overstaying two days and was given a one-year ban.   I have to travel to Malaysia in January 2019. I am concerned whether I will be allowed or face any problems flying via South Africa. I have a flight from Botswana to South Africa, then to Hong Kong and on to Malaysia. Will I have a problem entering South Africa or will they grant me access as long as I am in transit?


how can I downcast proper class from vector?

Dog is base object  class dog {     void bark(); (print : I am dog) }   and a lot of child class from dog  class Puppy : Dog {     void bark(); (print : I am a purry) }  class Puddle : Dog {     void bark(); (print : I am a puddle) }   put many kinds of child class into "Vector dogs"  Vector<Dog *> dogs;  dogs.pushBack(puppy); dogs.pushBack(puddle); dogs.pushBack(martiz); dogs.pushBack(yok);  for (auto dog : dogs) {     dog->bark(); }   all class print "I am a dog"  I want to downcast automatically their origin class.  what is the best way for my case?


My preamble is as follows:  \documentclass{llncs} \usepackage{xcolor} \usepackage{harvard} \usepackage{listings} \usepackage{chngcntr} \makeatletter \lst@InstallKeywords k{attributes}{attributestyle}\slshape{attributestyle}{}ld \makeatother  \definecolor{bluekeywords}{rgb}{0,0,1} \definecolor{greencomments}{rgb}{0,0.5,0} \definecolor{redstrings}{rgb}{0.64,0.08,0.08} \definecolor{xmlcomments}{rgb}{0.5,0.5,0.5} \definecolor{types}{rgb}{0.17,0.57,0.68} \definecolor{cyan}{rgb}{0.168,0.568,0.686}  %\counterwithin{lstlisting}{section}  \lstset{language=C++, basicstyle=\ttfamily, literate={~} {$\sim$}{1}, showspaces=false, showtabs=false, breaklines=true, showstringspaces=false, breakatwhitespace=true, escapeinside={(*@}{@*)}, commentstyle=\color{greencomments}, keywordstyle=\color{bluekeywords}\bfseries, stringstyle=\color{redstrings}, basicstyle=\ttfamily, morekeywords= {  abstract, event, new, struct,    as, explicit, null, switch,    base, extern, object, this,    bool, false, operator, throw,    break, finally, out, true,    byte, fixed, override, try,    case, float, params, typeof,    catch, for, private, uint,    char, foreach, protected, ulong,    checked, goto, public, unchecked,    class, if, readonly, unsafe,    const, implicit, ref, ushort,    continue, in, return, using,    decimal, int, sbyte, virtual,    default, interface, sealed, volatile,    delegate, internal, short, void,    do, is, sizeof, while,    double, lock, stackalloc,    else, long, static,    enum, namespace, string, var, \#region, \#endregion }, moreattributes={Assert, Test, GeneticAlgorithmHarmonizer, ExpectedException, InvalidElitismRate, InvalidMutationRate, InvalidPopulationSize,  ScoreManagementUnitTests, TestFixture, Double, Int32, MusicalStyle, KeySignature,     TimeSignature}, % etc... attributestyle = \bfseries\color{cyan}, % (for instance) backgroundcolor=\color{black!5}, % set backgroundcolor basicstyle=\footnotesize% basic font setting }   I have the following listing in my document:  \begin{lstlisting}[basicstyle=\ttfamily, caption={class foo managing private memory},label={lst:baseFoo}]  class foo {   public:     foo() { aReallyLargeArray = new char[123456789]; }     ~foo() { delete [] aReallyLargeArray; }   private:     char* aReallyLargeArray; };  int main(int argc, char** argv) {    foo bar;   }  \end{lstlisting}\bigskip   However, indentation in the input is not preserved in the output. Note how the ~foo() destructor is indented much more than foo on the previous line. This improper indentation occurs in other listings of mine as well. I suspect it has to do with the ~... Any thoughts?


Converting char* to int and converting back to the same char array

Basically, I am trying to increment the int value of port. This should be easy but I am a little stuck.    It compile fine, but I got this error when I run it:  Access violation writing location 0x001f5834   #include "stdafx.h" #include "iostream"  using namespace std; #define TESTING "5002" int main() {     char* port = TESTING;     int portint;     sscanf ( port, "%d", &portint );     portint++;     cout << portint << endl; // it works fine up to here, it prints 5003     sprintf ( port, "%d", portint);     return 0; }


how to interpret if the coefficients of two predictors are positive,the coefficient of the interaction term is negative?

I have a multiple regression model.The predictors A,B,AB are all significant. But the coefficients of A and B are positive while the coefficient of AB is negative. How to interpret it? (A ranges from -1 to 1, while B>=0)Thanks!


In the TNG episode "", we see Data's travel bag opened to show various items of relevance.  On it, it appears that Data has some other titles, names, or honorifics.  It reads as “Lt.Cmdr. ???/??? Data”, where between his (known) name and rank there seems to perhaps be text (possibly a series of acronyms?) but it's not clear.  Are these symbols simply patterns and line art filling up space, or is there some other meaning here?


Remove list of elements before iterating in java

I have a String List.On a satisfied Condition ,I need to group strings and remove those before iterating. For example;  List<String> test = new ArrayList(); List<String> newLst = new ArrayList(); test.add("A1"); test.add("A2"); test.add("A3"); test.add("A1B1"); test.add("C1"); for(String s: test){     if(s.startsWith("A"){         newLst.add(s);         test.remove(s);     } }   Once A1 reaches the loop,collect related string in new list and remove it from existing.  Getting Concurrent Modification exception.Kindly help to solve this.  Output: newLst: A1,A2,A3  test : A1B1,C1  newLst : A1B1 test:C1  newLst : C1


How to create a strong halo light effect?

How to achieve the strong light effect (you may see in some games and 3d renders), where the light is so strong it's penetrating the objects?


Can I safely connect the power-only-end of a USB-Y cable to an other power source?

If the host computer for an USB device doesn't provide enough power for a device which has no dedicated power port, can I connect the power-only-plug of a Y-USB-cable to an other computer, an USB-charger or even a regular mobile charger? I'm afraid this could damage some of the devices.  Edit: The device in question is a USB Hard drive (Samsung S2 Portable 640GB (but on the back it's written to use 0.85A)) which is supposed to work whit just a single USB port. It did so well on a other laptop and whit some cables even on my actual net book back in Europe. But now in Malaysia it works only some times (I still try to figure out what the conditions are) and then it stops working after a while (maybe when it goes to power save mode). I heard from others their hard drives need one more power plug here in Malaysia to but can't imagine why...


How to start/open a file/folder that contains space in its name through command-line?

I'm trying to use the start command in the command prompt to open files and folders, but I'm unable to open files and folders that contain space(s) in their name.  I have tried the following queries (testing on C:\Program Files):  start C:\Program Files start C:/Program\ Files start C:/"Program Files" start C:\"Program Files" start "C:\Program Files" start "C:/Program Files" start C:/Program_Files start C:/Program%20Files   But none of them work.


What is the definition of $2.5!$? (2.5 factorial)

I was messing around with my TI-84 Plus Silver Edition calculator and discovered that it will actually give me values when taking the factorial of any number $n/2$ where $n$ is any integer greater than $-2$. Why does this happen? I thought factorials were only defined for positive integers and $0$, so what is my calculator doing to get the answer $3.32335097$ when I enter $2.5!$? Is there actually a definition of $2.5!$ or is my calculator just being weird? How is the factorial function implemented?  I understand the binary implications of $2.5$, so that could possibly have something to do with it. I get a domain error when trying to take the factorial of $-1, 2.3, e$, and any number that is not of the form $n/2$ where $n$ is any integer greater than $-2$.


Is there a straightforward word for "The thing in between first and second"?

Sometimes when writing I find myself looking for a word to describe something in the “³⁄₂th” place — exactly between first and second.  I would like to ask, does there exist an easy expression for this?  If so, does it generalise to other “in-between” places as well?  (I mostly encounter this problem when writing mathematics, where I wish to write the “³⁄₂” order derivative, and normally have to endure clumsy or imprecise expressions (“Taking the fractional derivative. . . .”).)


Inverse image of maximal ideal under $k$-algebra homomorphism is a maximal ideal.

Let $k$ be an algebraically closed field, let $R,S$   be finitely generated $k$-algebras without nonzero nilpotent elements.   Let $f\in \text{Hom}_k(R,S)$, and $M$ a maximal ideal of $S$. Then $f^{-1}(M)$ is a maximal ideal of $R$.   I've thought of this proof:  We know that $R/f^{-1}(M)$ is an integral domain which "contains" $k$.  Furthermore the homomorphism $f$ with the canonic epimorphism $S\to S/M$ induces an homomorphism $f'=\sigma\circ f:R\to S/M$. By fundamental homomorphism theorem we have a monomorphism $f'':R/f^{-1}(M)\to S/M$.  Abusing notation we can say then:  $$k\subseteq R/f^{-1}(M)\subseteq S/M=k$$  since $S/M$ is a finite extension of $k$.   Then $R/f^{-1}(M)=k$ and thus $f^{-1}(M)$ is a maximal ideal of $R$.  I have seen other proofs, which extend a bit more, to prove that $R/f^{-1}(M)$ is a field, not necessarily $k$ (but with the hypothesis for $k$ to be algebraically closed). So I have some questions.   Is my attempt of proof correct? Is there any problem in the abuse of the notation? I haven't used the fact that the algebras are reduced, but when I found the proposition the first time , the hypothesis was there. (The proof attempt and the answer seemed too crazy for me so I thought in trying to prove it myself.) In other places it does not appear, like . Does this hypothesis contribute in any way? Does $k$ have to be algebraically closed?


Can an Object Look as Dense as a Black Hole in Special Relativity?

I don't know much about relativity, so I hope my question doesn't seem ridiculous.   From the equivalence of mass and energy we know that a moving object looks heavier from an observer's point of view. It means the object looks remarkably denser at high speeds. Relativistically, is it possible for an observer to see the object as a black hole (something from which even light can't escape)? Of course, this conclusion is paradoxical since there are observers that see it lighter and less dense. Where am I going wrong?


Can't delete preferred networks from wireless settings (comes back up)

I am having an issue with preferred networks in WiFi settings. There are few networks I want to delete - when I do so, the disappear temporarily, but will eventually come back. I believe is to do with iCloud saving passwords.   Let's say I delete network from my iPhone (also on my macbook), after day or two I will notice my iPhone or Macbook connecting to the same hotspot again (shared, so this is a security issue), and I will go in to preferred network settings and will see all the networks I have already deleted.   Do any of you have a similar issue?  Because of security issue I had to enable password protection for network switching on my macbook, and keep wifi disabled when unused on my iPhone.  I have also submitted bug report to Apple, but did not get any response or comments back.


Can't make anything other than folder in C:\ Windows 8

Since Windows XP I could make any type of file I wanted in C:. I could right click, and make a text file that I could create logs with, etc.   Now, in windows 8 though, I can't make anything in C:\ other than a folder. I assume it's because of my privileges. I need to be able to make files in C:\ on demand.   Any ideas?


Merge unallocated partition to root partition

I am not able to resize my root. I want to merge the unallocated space to my root partition. My gparted screenshot looks like


Game Development Degree vs Computer Science Degree

I'm at the point in my life where I'm starting to look at schools, and was hearing a lot of mixed things about schools such as Digipen or Fullsail that target game development specifically. As someone who is planning on becoming a programmer and getting into the games industry, would getting a game development degree be better than a traditional computer science degree?


Why not to initialize a neural network's weights to zero?

The  mention not to initialize all the weights to zero, because:     … if every neuron in the network computes the same output, then they will also all compute the same gradients during backpropagation and undergo the exact same parameter updates. In other words, there is no source of asymmetry between neurons if their weights are initialized to be the same.   I have been trying to understand this, but it is still not clear to me. I have searched on the internet, where some sources have only managed to confuse me further, like  and some other sources claiming that if the weights are initialized to zero, the weights would not update at all during the whole training process (while according to the notes linked above, the weights will update, but the updates to all the weights will be equal)  I tried doing some calculations on my own, which I have attached below.     If I have not made any error then then this derivation is showing that all the weights would undergo updates of equal magnitude, but the weights in the row of the Weight Matrix corresponding to the true class would be updated in the opposite direction compared to the other weights. So if the other weights are increased by delta, the weights in the row corresponding to the true class would be decreased by delta. So when the notes say "(all the neurons would) undergo the exact same parameter updates", they are actually talking about the magnitude – the direction can be different for some weights.  I am no expert in Mathematics, so, if there is any error in the derivation above, or if I am not interpreting it right, your criticism of it would be appreciated. Also, if there is a more intuitive way to see this, that would be helpful


Getting crash in android NullPointerException in updateLocaleListFromAppContext

I have an app uploaded on PlayStore and getting crash on it java.lang.NullPointerException from android.app.ActivityThread.updateLocaleListFromAppContext  I have tried searching a lot online to check where this error could be coming from. I'm not natively using this method call specifically for anything in the code.  java.lang.NullPointerException:    at android.app.ActivityThread.updateLocaleListFromAppContext (ActivityThread.java:5892)   at android.app.ActivityThread.handleBindApplication (ActivityThread.java:6127)   at android.app.ActivityThread.access$1200 (ActivityThread.java:240)   at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1797)   at android.os.Handler.dispatchMessage (Handler.java:106)   at android.os.Looper.loop (Looper.java:214)   at android.app.ActivityThread.main (ActivityThread.java:7076)   at java.lang.reflect.Method.invoke (Method.java)   at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:494)   at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:965)   Please help if anyone knows the solution or where I can start looking to resolve this.


How to set theme for GNOME (GTK) apps opening as root

I use Kubuntu 19.10 and when I open GNOME apps like Nautilus or Gedit as root, they do not show in theme (Qogir-dark) that  I choose for GNOME apps, but in some strange black and white theme.   I tried to put Qogir folder to /.themes, but nothing (currently it is in /usr/share/themes). How can I correct that?


Was the ‑e at the end of bye deliberately added in order to distinguish it from the word by?  Did they do that so that that way, even though the two words sound the same, they look different when written and you’d be able to tell which is which when you read them?   Is that kind of thing something that English has done in the past, changed their spellings so that words that sounds alike are written differently?


Does C# have an equivalent to JavaScript's encodeURIComponent()?

In JavaScript:  encodeURIComponent("©√") == "%C2%A9%E2%88%9A"   Is there an equivalent for C# applications? For escaping HTML characters I used:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m => @"&#" + ((int)m.Value[0]).ToString() + ";");   But I'm not sure how to convert the match to the correct hexadecimal format that JS uses. For example this code:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m => @"%" + String.Format("{0:x}", ((int)m.Value[0])));   Returns "%a9%221a" for "©√" instead of "%C2%A9%E2%88%9A". It looks like I need to split the string up into bytes or something.  Edit: This is for a windows app, the only items available in System.Web are: AspNetHostingPermission, AspNetHostingPermissionAttribute, and AspNetHostingPermissionLevel.


Do we have a SE site about marine engineering?

There's a site on Area 51 about Engineering, but I don't know if we have like a branch of that site talking about marine engineering. You know, like, the building of big ships, oil rigs, etc.


My UK visitor visa got refused, Should I reapply?

I got this refusal letter: 1- It seems to me the ECO has not understood my blocking account status that is 8740 Euros.  2- I am a student in Germany, I have obtained the money in both my blocked account and my personal current account in Iraq where I worked for 5 years.  3- I am fully sponsored by my fiancee, but he has ignored this and the evidences with it. What shall I do? It is really important to me to visit her for these three weeks, because here in Germany I live in a shared flat. It is not possible for her to come and live with me here. if I reapply explaining my financial situation, do I have a chance of getting it?   I appreciate your kind responses.


How to solve $x^2 +\left(\frac{x}{x-1}\right)^2 =8$?

I tried to solve this question but it turns into a 4th degree equation and I could only get one solution for this equation,i.e., 2. It is to be evaluated for solutions. Thanks.


Can I use my Windows 7 CD to install Windows 7 on my other computer?

I just bought a laptop with Windows 7. I have a desktop that is still running Windows XP. Wil it let me install Windows 7 on my desktop with that CD or does Windows only allow that CD to be used for the laptop?


Featuring scaling whole data set before spliting it.

I am wondering why do we use scaling on train and test set separately. I understand that transform () on test data  μ and σ as computed from fit_transform() on  Train. But why can we compute μ and σ from all given data (before split) and then apply them on future data.   Do we do this because we don't know how the size of our future data?


It seems that Disk2VHD captured an entire HD rather than the boot partition (232GB versus 125GB)  I am hoping to bring up an image of my XP Pro box inside Windows 7 Ultimate x64 as a Virtual PC.  Originally the boot partition on the XP box was 232GB but I used Acronis Disk Manager to shrink it to 125GB, resulting in unallocated space of 107GB on the HD.  Inside Disk Management console it looks like this on the XP box:  ............ primary...................unallocated Disk 0      MYVOLUME (C:)              XXXXXXXXXXXXXX Basic       125.00 GB NTFS             107.88 GB 232.88GB    Healthy (System)           Unallocated Online   and Disk2VHD has this  Volumes to include:....Size...........Free........Space required [x] C:\ MYVOLUME       125.00GB       33.26GB.....94.22GB   I checked the feature to [x] Prepare for use in Virtual PC when creating the VHD with Disk2VHD. However, Windows 7 Virtual PC cannot attach to the VHD. So I downloaded VirtualBox to see what would happen. VirtualBox just opens a black rectangle and the disk never boots; it shows the full size of the VHD as 232GB  (that is, the 125GB system partition plus the 108GB unallocated).  Is the size of the original disk what is preventing Virtual PC from attaching?  I was hoping that shrinking the boot partition would cause it to fall within the 127GB limitation.


Combining generic "one", "he" or "they" in a convoluted sentence

What is the best and what is acceptable from the following sentences?  If one finds oneself in a situation where one's own life is at stake, one should think of oneself first. If one finds himself in a sitation where his own life is at stake, he should think of himself first. If one finds themselves in a situation where their own life is at stake, one should think of themselves first.


I can't wait to download ubuntu 14.04. When wil it be able to download? And will I be able to turn on wifi and bluetooth? please answer


Connecting three houses to three utilities

When I was a child I was given this problem to send a wire from electricity, water, and internet to each of the houses, all three houses must have all three wires connected without being crossed over each other (wires can't meet and there is no such thing as a wire going on top of another wire) , I have always gotten to the point where I can connect all but except one wire.   Now after many years this just came to my mind today, and I wanted to ask why isn't it actually possible? What makes the last wire so special? That u can't connect the 9th wire in a 2D plane. Let me know if anyone know how to solve it or if anyone knows a proof (in layman terms) as to why it's Impossible.


Any rule for using nationality as a noun?

As you know there are times when using a nationality (without any modification) is a correct way to refer to a person of that nationality and there are times when it is incorrect. For example "He is a German" vs. *"He is a French".  Are there any rules for deciding if a nationality can be used as a noun?


Prime numbers the rank of which is also a prime.

$127$ has an interesting property: It is the $31$st prime number and its rank ($31$) is also a prime. $31$ is the $11$th prime so its rank is also a prime. $11$ is also a prime number with a rank ($5$) that is also a prime. $5$ is the 3rd prime number and and so its rank ($3$) is also a prime. And finally $3$ is the $2$nd prime so its rank is also a prime... Is there a name for primes whose rank (index in the prime series) is also a prime? That is:     If $a_i$ is the $i$th prime number, then $i$ is a also a prime.   How about numbers like $127$ where going down ranks of ranks always produce prime numbers (down to rank $2$ of course)? The first $11$ :-) primes in this (infinite) series would be:  $3, 5, 11, 31, 127, 709, 5381, 52711, 648391, 9737333, 174440041, \dotsc$  Many thanks!


Prove that the sum of digits of $(999...9)^{3}$ (cube of integer with $n$ digits $9$) is $18n$

Someone had posted a question on this site as to what would be sum of digits of $999999999999^3$ (twelve $9s$ ) equal to?   I did some computation and found the pattern that sum of digits of  $9^3 = 18$,  $99^3 = 36$,  $999^3 = 54$ and so on. So, I had replied that sum of digits of  $999999999999^3 = 12 \cdot 18 = 216$.  Can anybody help me prove this, that sum of digits of  $(\underbrace{999\dots9}_{n\text{ times}})^3 = 18n.$


Diophantine equation $ax + by = c$ has an integer solution $x_0, y_0$ if and only if $\gcd(a,b)|c$

Let $a,b,c$ be positive integers.  Verify that Diophantine equation $ax + by = c$ has integer solution $x_0, y_0$ if and only if $GCD(a,b)|c$. Attempt Diophantine $ax + by = c$ has integer solution $x_0, y_0$ implies $GCD(a,b)|c$. Factoring out $ GCD(a,b)$ from each side gives $$\frac{1}{GCD(a,b)}(ax + by) = \frac{1}{GCD(a,b)}c$$ which must still have an integer solution as $GCD(a,b)$ obviously divides both $a$ and $b$.  If $GCD(a,b)$ does not divide $c$ there is no integer solution. That $GCD(a,b)|c$ implies that $ax + by = c$ has integer solution $x_0, y_0$. Let $c = GCD(a,b)d$, where $d$ is integer. $ax + by = GCD(a,b)d$;  divide both sides by $GCD(a,b)$: Obtain $mx + ny = d$ with $GCD(m,n) = 1$.  If $d$ is an integer and $GCD(m,n) = 1$ then $x,y$ must be integers as $mx + ny$ cannot be further divided evenly. or $ax + by = c$ has no solution implies $GCD(a,b)$ does not divide c. $c = GCD(a,b)(\frac{ax}{GCD(a,b)} + \frac{by}{GCD(a,b)}) + r$ with $GCD(a,b) > 0, 0<r<GCD(a,b)$, r integer $\frac{c}{GCD(a,b)} = \frac{ax + by}{GCD(a,b)} + \frac{r}{GCD(a,b)}$


Is there any way to graceful restart mysqld?

I think my question is impossible but I sure I do not know everything.   In my opinion, when mysqld restart, some transaction is not still completed will be rollback on startup. Mysqld use undo log to do it. But is there any way to keep long transactions on restarting mysqld ?  I am using MariaDB Galera with three nodes.


I will be travelling soon to the US from Jakarta. I have both US and Indonesian passports. Indonesia does not recognise dual citizenship, yet the US requires me to enter and exit the US with my US passport. I've read that I can go to Singapore first and then fly out to the US. But which passports to use and how?


SF novel with a star system surrounded by a shield/force field; main character is an alien made of several individuals

Was lent a book a few years ago.  May have been part 1 of 2 or 3.   Humans identify a star system which is quarantined; surrounded by some sort of shield or force field. Within the shield boron fusion-powered spaceships operate.  The central character from early on in the book is an alien life form which is formed of four (I think) individuals who grow together / combine to form a compound intelligence but lack the ability to move; they have unintelligent drone lifeforms which can move and obey commands.  They're implacably hostile to all other life forms, hence the quarantine; it wasn't to keep others out but to keep this race in.  The compound life form continues to grow by assimilation; can't remember its name but it includes "Mountain".  A human exploratory team is captured and dissected by the drones as "Mountain whatever" tries to work out the nature of the threat.


Why does $\lim\limits_{x\to\infty}(x!)^{1/x}\neq 1?$  As far as I know, anything to the power of $0$ is $1$.  We have a factorial raised to $1/\infty=0$, but the limit is not $1$? I don't even know what the limit is. But it seems like infinity? Why is this?


Why am I getting shocked by a water heater?

I saw this question earlier, and wrote a lengthy answer for it (offline, as the text editor is not friendly to embedded graphics).  When I went to post the answer, the question had .  It had 0 answers at the time.  My best efforts to search for it yielded nothing. So I am re-summarizing the question here, and posting my answer.  I am in the Philippines, and I am getting shocked by my shower with electric hot water heater.   The Philippine codes are very similar to American NEC.  We are getting new 240V service installed.   While we wait, we are using the old service that was present.  This provides 220V/240V between only two wires, and does not provide a neutral.  I installed a new 8' grounding rod, and measured from the grounding rod to each wire, and got 120V.  The shower is a Panasonic DH-3JL2P.  It wants hot, neutral and ground.  It is giving me quite a strong shock.  Why is it doing this?


What does the subscript on a fraction mean in this sequence equation?

I need to know what the subscript $n-1$ means in the following equation: $$a_n = -\frac{1}{3} (-1)^n (\frac{2}{3})_{n-1}$$ I tried treating it as an exponent but that is not correct. The first five outputs of this are $\frac{1}{3},-\frac{2}{9},\frac{10}{27},-\frac{80}{81},\frac{880}{243}$.


Dynamical max height of div based on parent

Let's say I have following:  .wrap { height:400px; } .header { height:100px; } .footer { height:100px; }

   Is there any CSS solution to have .middle_row be dynamically stretched to 200px?


Does the Elemental Gem require Concentration?

Does an elemental summoned from an Elemental Gem require Concentration? I am getting hung up on the "as if you had cast" part. Other items say, "you can use an action to cast the [spell]".   This gem contains a mote of elemental energy. When you use an action to break the gem, an elemental is summoned as if you had cast the conjure elemental spell, and the gem's magic is lost. The type of gem determines the elemental summoned by the spell.   Related question:  The distinction I'm asking then is if the Elemental Gem is a spell or a spell-like effect.


This is a crop of my render test with cycles.    My Workstation: Win10, GPU Compute with NVIDIA 1050Ti How can remove all the light pixels in the scene?  Render settings


Banach Alaoglu Theorem vs Sequential Banach Alaoglu Theorem

The Banach-Alaoglu says that the closed unit ball in a dual space $X^*$ of a normed space $X$ is compact in the weak-star topology.  The sequential Banach-Alaoglu says that the closed unit ball in a dual space of a separable normed space is sequentially compact in the weak-star topology.  According to page 71, example 5.3.1 ii) , the assumption of separability cannot be dropped in the sequential Banach-Alaoglu. The proof makes sense to me. However I also reason that the (strong) Banach-Alaoglu covers the sequential Banach-Alaoglu as a special case. So by Banach Alaoglu, shouldn't the sequential Banach Alaoglu theorem still hold true for $X$ inseparable?


unable to boot to Xubuntu after choosing to install it

I was trying to boot Xubuntu, Ubunto, and many other variants, initally on BIOS my USB stick  was never detected to boot from, so after reading online I found out that I need a (bootia32.efi) to be placed in ISO Root - EFI/BOOT, I copied the (bootia32.efi) to that directory and my USB Sitck was detected in BIOS menu, now selecting to boot from the USB  Stick, brings up the menu of installation to chose from, I tried all options in that boot screen such as (boot to Xubunut without installing, Installing Xubntu, etc) and I was only presented with a black screen that dont seem to do anything, and of course I manually edited my BIOS to turn off secure boot, and placing the USB stick on top of the boot order, after digging further am starting to suspect that in EFI/BOOT I would need a (grubia32.efi) since am running windows 10 with x86 processor and a 32bit which does't support x64 grub, can anyone help on how to get a grubia32.efi so I can see if it boots? thanks a lot in advance!


MikteX portable version 2.9 requiring package file .sty and not working with .dtx

I downloaded this morning the latest version of MikteX portable (2.9) on Windows to update my old version (dating back from 2013 I would say). I have a personal directory with some additional packages I use (with the right architecture, e.g. myfilefortex\tex\latex). I set the MikteX options to install those packages (by adding the path of my personal directory as a root and refreshing the FNDB). I had already used those packages with my old MikTex portable version and it was perfectly working. When I compile with TexMaker (pdfLatex) and my new MikteX version, it doesn't find the file 'subcaption.sty'. I checked, I only have a 'subcaption.dtx' file, which was working before... and the CTAN package 'caption' containing 'subcaption' only provides the .dtx file (and not the .sty file). And concerning the installation of a .dtx file, the .ins file which could help (I read that in some others answers) is not provided with the package.  Could anyone help me with this issue please ? Is there a way to get a .sty file from a .dtx ?  Thanks very much for your answers


How to add electrical fixtures to (custom) furniture?

Having electrical outlets, USB charging ports, night lights, etc would be nice to have on some pieces of furniture, like side tables. Several receptacle manufacturers make combination fixtures with USB and power, for instance, or power plus a night light.   I've thought about nailing an electrical box to a (hidden) portion of the table and putting one of those receptacles in it, but what things do I need to consider doing this? Is it as simple as it sounds,  and then just fashioning some kind of plug out of 12/2 or 14/2 wire? Does the answer change if the box is concealed (though still accessible) vs it being completely visible?


which dimenstions contributed to change in percentile?

We report 95th percentile and 50th percentile of the time series data for every week. The data is time-series data in the following format  date. sensor_id. sensor_location. hardware_version. sensor_value 2021-01-01. S1. L1. V1. 10. 2021-01-01. S2. L2. V2. 20. 2021-01-01. S3. L1. V1. 12. 2021-02-01. S1. L1. V3. 30. 2021-02-01. S2. L2. V3. 40. 2021-02-01. S3. L1. V2. 32. The problem we are facing is to understand what caused the change in percentile week over week. For example some weeks the p90 is very high and we would like to know what sensor or which location or which version caused the big jump in p95. Could you please help what's the best way to solve this problem?


I am using \begin{equation} \end{equation} to number my equations in my text. But I normally mention these equations in the further text. E.g., In equation 3 ....   But if I change the former equation number I have to search in the text where I mentioned it.   Is there any way to link those numbers so when I change the equation number it automatically changes the furthers mentions about it in the text?


What is the proper way to add a required field to a post type?

So I created a CPT that has a few required fields in a metabox. My metadata is being saved through the save_post hook but from I can find via my googlefu there is no way to stop the saving of the post from this hook.  Currently I'm stopping the submission of the form using javascript but I would also like to have a server side solution for this.  I guess I have a few questions:   Why was Wordpress developed so you can't stop the post submission? What is the accepted way to do this?


How to center a spinner horizontally and vertically in page?

I have a div block that simulates a small spinner, everything works fine however with the css configurations that I have it is positioned in the upper right wing, I tried to center it but when I see it from a mobile device it moves from place .. how could to center it without it changing position in devices with different sizes?  .spinner {   display: block;   position: fixed;   z-index: 1031;   top: 15px;   right: 15px; }


Is there any order of dictionary value print in python?

When we print values in a dictionary, is there any default sorting that use to print the keys and values in a Python dictionary? Or do they randomly print the key , value pairs?  Please see below code. is there any order of dictionary value print in python?  confusion = {}  confusion[1] = 1 confusion[4] = 22 confusion['5'] = 2 confusion['2'] = 2 confusion[1.0] = 4 confusion['1'] = 2  print confusion   The result is {'2': 2, 1: 4, '1': 2, '5': 2, 4: 22}


Create folder in same directory as shell script

I'm new to Shell Scripting:  I'm trying to create a script that asks for user input as to the folder name, finds the directory the script is being run from, and creates a folder within that same directory with a bunch of files (I can do that part)  My issue is I can't seem to figure out how to make the script find its current directory without explicitly spelling it out.   I want to be able to run it from anywhere and have it create the folder right next to it without the user having to path it from the home folder every time.  Could someone help with this?


How to prove $\lim\limits_{n\to\infty}\left(1+\frac{1}{n}\right)^n=\sum_{k=0}^{\infty}{\frac{1}{k!}}=:e$

I have already proven that $\left(1+\frac 1{n}\right)^n\leq \sum_{k=0}^{n}{\frac{1}{k!}}$ . Does that help me in any way? I am stumped...  Any suggestions/hints?


Prove that some topology is not metrizable

Suppose I am asked to show that some topology is not metrizable. What I have to prove exactly for that ?


Evaluate $L=\lim_{n\rightarrow\infty}\sqrt[{n+1}]{(n+1)!}-\sqrt[n]{n!}$   How I approached it and where I get stuck:  $$\lim_{n\rightarrow\infty}\sqrt[{n+1}]{(n+1)!}-\sqrt[n]{n!}=\lim_{n\rightarrow\infty}\frac{\sqrt[n]{n!}}nn(\frac{\sqrt[{n+1}]{(n+1)!}}{\sqrt[n]{n!}}-1)$$  Now:  $$\lim_{n\rightarrow\infty}\frac{\sqrt[n]{n!}}n=\lim_{n\rightarrow\infty}\sqrt[n]{\frac{n!}{n^n}}=\lim_{n\rightarrow\infty}e^{\frac1n\sum_{k=1}^n\ln(\frac kn)}=e^{\int_0^1\ln(x)dx}=e^{-1}=\frac1e$$  So $L=\lim_{n\to\infty}\frac 1e\times n(\frac{\sqrt[{n+1}]{(n+1)!}}{\sqrt[n]{n!}}-1)$. Now this is where I get stuck. What should I do?


How do we know the precise speed of light in a vacuum?

From Wikipedia - "Its exact value is 299792458 metres per second"  I'm wondering how we can be so precise as to the speed of light given that we cannot create a true vacuum on Earth and as I understand it the interstellar vacuum is a lot more active than we used to think with particles and anti-particles appearing and annihilating each other constantly. Is there a caveat here that should say "Exact value as measured at vacuum density x"?  Apologies if this is a duplicate, I did find several questions regarding the speed of light, the type of vacuum and whether it's a constant but couldn't find one that dealt with the precision of the measurement.


Upgrading from Windows 7 32-bit to Windows 7 64-bit

I am upgrading from Windows 32-bit to Windows 7 64-bit.  If I choose CUSTOM option and install Windows on C: drive - will it wipe out all the data:   On C: drive?   or    On all my drives?


Formating number string with commas for currency type dispaly

Is there an easy way in python to format a number with commas ie 11222.33 would print as: $11,222.33.  Currently I'm doing something like:  def formatMoney(number):     res = str(number)      # Number of digits before decimal     n = res.find('.')     n = n if (n >= 0) else len(res)     if n < 4:         return res[:n+3]      # Location of first comma     start = n % 3     start = start if (start > 0) else 3      # Break into parts     parts = [res[:start]]     parts += [res[i:i+3] for i in range(start, n - 3, 3)]     # Last part includes 3 digits before decimal and 2 after     parts += [res[n-3:n+3]]      return ",".join(parts)   But I feel like I must be reinventing the wheel here. Have I missed a package in the standard library, or a more obvious way of doing this?


Flair with a lot of badges wraps to a new line

I was looking at  by  and noticed that their flair had a newline in it:    I have no idea if this is a bug or not, but it kinda looks wrong to me. For fun, I changed all badge counts to 9999 and the user-info user-hover <div> that wraps the whole thing needs a width of 210px instead of 200px.


Teen fantasy book series about a world where people who showed creativity could learn magic, and were killed for it

The first book starts where the main character shows creativity, and is sent presumably to his death. He then ends up in a secluded area run by a caretaker where they learn to use their creativity and art as magic. The two sides go to war, one led by the main character and the other by his twin on the other side. In later books, they learn that they live on an island in a chain, and multiple books deal with those other islands. They learn from someone from our world that they live in the Bermuda Triangle, and they also wrap around to the other side of the island chain if they go to the end via a giant waterfall. Some random things in there are magical sentient whiteboards and statues. A sequel series was released recently, detailing the children and their adventure. That's about all I can recall, can't remember names of anything.


What is the difference of the two methods to initialize a nested list in Python

I want to transpose a matrix, and I use two method to initialize a nested list as a new matrix.  The first method to initialize a nested list is   re = [[0 for j in range(len(A))] for i in range(len(A[0]))]   The second method is  re = [[0]*len(A)]*len(A[0])   The code to transpose a matrix is as follows.  class Solution:     def transpose(self, A):         """         :type A: List[List[int]]         :rtype: List[List[int]]         """         l = len(A[0])         # method 1         re = [[0 for j in range(len(A))] for i in range(len(A[0]))]         # # method 2         # re = [[0]*len(A)]*len(A[0])         for i in range(len(A)):             for j in range(l):                 re[j][i] = A[i][j]         return re     def test(self):         print(self.transpose([[1,2,3],[4,5,6]]))  tran = Solution() tran.test()   However, the result of transposing a matrix by using two methods are different.  Output:  # mehtod 1 [[1, 4], [2, 5], [3, 6]]  # method 2 [[3, 6], [3, 6], [3, 6]]   Anybody can tell me the difference of this two method to initialize a list？


I have windows PC with a VM installed.  I installed Ubuntu 20.04 to learn Linux. I am unable to install anything due to an Authentication required. I have seen there is a way to disable this authenication requirement. Is there a script or a list of the commands to disable it?


What is it called when we speak of foods using brand names?

I am wondering about the phenomenon of brand names being commonly used to describe certain foods.  For example, I recently heard the phrase “to eat cheetos“.  Other examples could be to eat/drink...   smarties kellogg's pepsi ...   Is there a word that describes this phenomenon of using brand names when referring to certain foods or drinks?  An example for one way of using it:     “I am sick of people who are constantly [word that describes the phenomenon of using brand names]!“


Having children while at graduate school

I am finishing my first year of Masters and have always thought of going for a PhD in North America. I and my girlfriend are going to have a baby which is totally unexpected. The due day will be somewhere this december which I am still half year away from finishing my Masters degree.   I don't know under this circumstance should I still, or am I able to, apply for PhD positions overseas. This would mean I will have to leave them or bringing them together for my study. I am not super rich to afford a family personally and would need to rely on studentships, but I don't think graduate studentships are sufficient to afford the living expense and future education fees of my coming baby.  Taking on a PhD and a research career are definitely my dream and situation seems very difficult for these to come true. Anyone knowing someone carrying kids along grad school, or any suggestion to me? I just don't have a clue how to take care of everything.


Two subfigures beside each other using circuitikz

I have a problem that I can't resolve. I want two put two circuits near to each other and not on top of each other. Here is my code  \documentclass{article} \usepackage{caption} \usepackage{subcaption} \usepackage{circuitikz}  \begin{document}  \begin{figure} \centering  \begin{subfigure}[b]{0.4\textwidth}  \begin{circuitikz} \draw    (0,2) to [american controlled current source, l=$g_m V_{GS_1}$](0,0) (2,2) to [R, l=$r_{o_1}$] (2,0) (3.5,2) to [american controlled current source, l=$g_m V_{GS_2}$](3.5,0) (5.5,2) to [R, l=$r_{o_2}$] (5.5,0) (0,2) to [short, -o] (6,2) (0,0) to [short, -o] (6,0); \end{circuitikz}  \caption{with $r_o$} \end{subfigure}  \begin{subfigure}[b]{0.4\textwidth}  \begin{circuitikz} \draw    (0,2) to [american controlled current source, l=$g_m V_{GS_1}$](0,0) (3,2) to [american controlled current source, l=$g_m V_{GS_2}$](3,0) (0,2) to [short, -o] (4,2) (0,0) to [short, -o] (4,0); \end{circuitikz}  \caption{with no $r_o$} \end{subfigure}  \caption{DC small signal model} \end{figure}  \end{document}     Can someone help me to figure out how to put the two circuits beside each other and not on top of each other?


I have windows 8 and ubuntu 12.04 LTS dual booted.. however, I have a partition with Windows 7 which does not have an entry in bootloader. How can I manually edit the GRUB so that I can get Windows 7, 8 as well as Ubuntu?


Searching and replacing with file contents

I want to search for characters in file and replace with file containing contents: search for ktr_updater in file and replace with file contents from another file using Unix commands.  sed -i 's/ktr_updater/'"$ktrupdate"'/g' samplejob.kjb


Define the projective quotient space as follows: $\mathbb{R}P^n$ is the quotient of $\mathbb{R}^{n+1}-\{0\}$ by the quotient equivalence relation $(x_0,\cdots,x_n)\sim (\alpha x_0,\cdots,\alpha x_n)$ for all $\alpha\neq 0$. Denote the quotient map as $r$. Consider the set $V_i=\{x\in\mathbb{R}^{n+1}:x_i=0\}$. Denote $U_i$ as $r(\mathbb{R}^{n+1}-V_i)$. Question: Prove $\mathbb{R}P^n$ is Hausdorff. My approach: I have proved that $U_i$ is open and Hausdorff for all $i$. Thus, for two distinct points $x$, $y$ in $\mathbb{R}P^n$, if there are in the same $U_i$, we can find two distinct open sets to separete them. But there are also points that are not in the same $U_i$. How do we deal with this kind of points? Update: Consider the diagonal set $\Delta(\mathbb{R}P^n)=\{(x,x):x\in\mathbb{R}P^n\}=\cup_{i}\{(x,x):x\in U_i\}=\cup_{i}\Delta(U_i)$. (The second equality is because $\{U_i\}$ forms a cover for $\mathbb{R}P^n$.) Because $U_i$ is Hausdorff, each $\Delta(U_i)$ is closed. This implies $\mathbb{R}P^n$ is Hausdorff. Is my proof correct? Thank you!


Question: Write the exponential form of $\sqrt{i}$.   My approach: Let $z=x+iy$ be such that $e^z=\sqrt{i}$. Thus we have $e^{2z}=i$. Hence we have $e^{2x+2iy}=i.$ This also implies that $|e^{2z}|=e^{2x}=1\implies 2x=\ln 1=0\implies x=0.$   Thus we have $e^{2x}\cos (2y)=\cos(2y)=0$ and $e^{2x}\sin (2y)=\sin(2y)=1.$ Thus $2y=\frac{\pi}{2}\pm 2n\pi, n\in\mathbb{W}$, which in turn implies that, $y=\frac{\pi}{4}\pm n\pi.$  Thus we have $\Re(z)=0$ and $\Im(z)=\frac{\pi}{4}\pm n\pi$.   Now observe that, $$e^z=\frac{1}{\sqrt 2}+\frac{1}{\sqrt 2}i,\text{ when $n$ is even, and}\\ e^z=-\frac{1}{\sqrt 2}-\frac{1}{\sqrt 2}i,\text{ when $n$ is odd}.$$   Also observe that indeed $e^{2z}=i,$ in both the cases. Hence, we can conclude that $$\sqrt i=\frac{1}{\sqrt 2}+\frac{1}{\sqrt 2}i, -\frac{1}{\sqrt 2}-\frac{1}{\sqrt 2}i.$$ Thus in exponential form, $$\sqrt{i}=e^{\frac{\pi i}{4}},e^{\frac{5\pi i}{4}}.$$   Is this solution correct and is there a better way to solve this problem?


I'm gonna try to run Linux on my pc. I was going to originally dual boot but found that it would cause too much trouble and I really would rather not mess with partitions. So, if I decide to erase everything and move to linux. How can I go back? would the recovery menu do anything? Do I need to make a second bootable usb of windows? This is really for peace of mind that I can go back if it turns out that I have problems with it. Please help because I would like to be prepared when I decide to switch from win10 to ubuntu.


Installing ubuntu 16.04 without losing data

Currently , I am running ubuntu 15.10 on my Dell laptop (ram-4GB) . I want to install ubuntu 16.04 LTS on my laptop as ubuntu 15.10 is no more supported. I don't want to lose my data while changing os , can I install 16.04 without losing data .   Thanx for helping in advance


Is it really impossible to calculate in advance the result of throwing dice? After all, the physics of dice throwing is in the world of classical mechanics, rather than quantum mechanics.


Generating contour lines and filled contours from points

I am trying to create contour lines and filled contours from a shapefile of height points using the contour plug in (have tried other tools but with no success).  The data is sourced from the UK Ordnance Survey in tiles of 400 x 400 points (NTF format). Each tile has been opened as a vector layer and then saved as a shp layer. The plug in will run properly with a single tile. However, the area I need is 3 x 3 tiles i.e. 1200 x 1200 points.   Initially I generated contour lines and filled contours for each of the 9 tiles. This is unsatisfactory since the spacing is slightly different for each tile according to its height range resulting in mismatch at tile boundaries. I then merged the 9 shp layers using the mmgis and vector menu merge. Running the contour plug in against either merged file fails with the dialogue box showing 'Not Responding'.  I am running QGIS 1.8 Lisboa on Windows 8 x64 pro with 32gb of memory and plenty of free disk space on all drives. I have had no problems with other imported layers, adding new layers of data. However, this is the first time I have attempted to generate a shaded layer or contour lines. I guess there must be a setting somewhere to allow the plug in to handle the larger data block - I found and increased the cache setting in 'options') or I am using the wrong tool for the job.  My project is mapping local history routes/settlements. The shading is needed to provide context.


I have earned the Peer Pressure Badge on my question on Stack Overflow. The question title is, "Setup And Deployment By Reading Bios Of User System". I don't know why I earned this badge; is there something wrong with my question? Did I do anything wrong with peers?


What is controlling the layout of customer view orders?

On the page located at user/%user/orders/%commerce_order, I am having a hard time figuring out what .tpl.php is dictating its layout.  Namely, I have tried editing commerce_backoffice/theme/commerce-order--backoffice.tpl.php and clearing the cache, but I see no change.  I know very little about theming and am not sure what I am doing wrong.


What is happening with this reference variable?

public class Reverse {  public static void main(String[] args) {     String [] simpsons = {"Homer", "Flanders", "Apu"};     reverse(simpsons);     System.out.println(simpsons[0] + " " + simpsons[1] + " "             + " " + simpsons[2]);   } //End main  public static void reverse(String[] list) {     String[] temp = new String[list.length];     for (int i =0; i<list.length; i++)     {         temp[i] = list[list.length-i-1];     }     //System.arraycopy(temp, 0 , list, 0, list.length);     list = temp;; }  }       I'm just getting started in Java, and this problem confused me. As you can see, I've solved the problem with the commented out arraycopy method. I'm simply confused as to why the list = temp still returns the original, non-reversed array. I believe I understand conceptually that references are just locations in memory, but doesn't list = temp assign the passed in array to the memory location of temp, AKA the reversed array?


Blank Desktop after Login on Ubuntu 14.04

I rebooted my system and receive a blank desktop after logging in. on getting into the shell with ctrl + alt + F1 and doing a "df" i see that my root partition is full with 100% usage.   I dont want to loose any data , how can i get my desktop back . Can someone please guide me through this.


I lost my game how could I return my account

townhall 8 level 8 base Max diffence troops I did not have any clan my base name is pran etc


Novel about a dragon lord who has to wear gloves at all times

I read this novel when I was young. It is probably a children's or young adult novel. I think I read it in 1997 or earlier. I remember very much enjoying it, but the title and most of the details are unfortunately quite hazy for me. Here is what I have:   The main character was a girl in her early teens (I think) She was sent to live with a man who was some sort of master of dragons She may have been related to this man (his niece, perhaps), but I also may have made that up The man wore gloves at all times. When he removed them and touched someone he could see something about them. Their future, I think?   Sound familiar to anyone?   Update: Thinking back on it some more, I think I remember that the dragon lord guy and the heroine ended up in some kind of romantic relationship (making it less likely that he was her uncle). Also, he did at one point take off his gloves and touch her, seeing her future (I think).  'nother Update: It's possible that I'm confusing dragons with volcanos. Or, there may have been both. And I think they lived on an island, or a coastline?


Any clue? Or is it just there for better visual?


How to disable mouse power status in indicator-power?

Today I have updated to Ubuntu 13.10 and got mouse power status.  But I didn't need it. And also Ubuntu doesn't know how long the mouse will work and shows   an ugly "estimating...".  How do you show only the battery status?


Relativity question. How to conceive two star ships receding from each other, each going near light speed

I'm a non-physicist so pls pardon this dumb question. (Maybe one of you high school physics teachers could use this to puzzle your students?) Say we're at big hard pan desert. A referee fires a gun and two cars on either side of him take off in opposite directions, each reaching a speed of 80mph. Relative to the man, they are both going 80mph away from him. But when the two cars look back toward each other, they can easily see (or measure by sonar) the other car receding at 160mph. Now say we're at some point in outer space and, when the referee gives the signal, two star ships start off in opposite directions, each reaching a speed of 80% of the speed of light (.8c). Now, the referee can see (using the red shift I guess) both ships receding at this speed. But what happens when the ships look back toward each other? Presumably they can't be receding from each other at 1.6c (.8c+.8c). If they shine a light beam back toward each other, could the crew on each ship ever even see the light beam from the other ship? It is really hard for me to conceive this situation. I know that the ships can not be exceeding light speed even relative to each other, and I guess this fact must somehow be reconciled by time, although I can't conceive exactly how. On another point, I've never been able to comprehend cosmologists when they say the Big Bang never originated in a certain point in space. Maybe it is the word "bang," which implies an explosion, and indeed they say the entire universe was condensed into a space smaller than an atom, right? I don't understand how you can have an explosion which does not originate in a specific point in space.


I want to send a cross domain ajax request but I am getting below error for this I have also tried the below code which I have got from the one stack article is it possible to send a cross domain request or not.  Code which I have tried for sending cross domain request.  $(document).ready(function () {     $.ajax({         type: 'POST',         url: "http://testdomain.com/config.php",         crossDomain: true,         data: 'rejected_by_loid=' + 1,         success: function (msg) {             $('#survey').html(msg);         }     }); });   Error on console log:  Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at . (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).  Please help me to solve this problem.


Adverb-adjective compound premodifier with or without hyphen?

Remarkably low condensation temperature  or  Remarkably-low condensation temperature?  The focus of remarkable is that it is such a low temperature. We are having an office disagreement and any help is much appreciated.


Show that $(\mathbb Z[x],+)$ and $(\mathbb Q_{>0},\cdot)$ are isomorphic groups

Let $(\mathbb{Z}[x],+)$ be the additive group of polynomials with integer coefficients and $ (\mathbb{Q}_{>0},\cdot)$ the multiplicative group of positive rationals. Show these groups are isomorphic.   Thanks


How to sample from a discrete distribution?

Assume I have a distribution governing the possible outcome from a single random variable X.  This is something like [0.1, 0.4, 0.2, 0.3] for X being a value of either 1, 2, 3, 4.  Is it possible to sample from this distribution, i.e. generate pseudo random numbers upon each of the possible outcomes given the probability of that outcome. So if I wanted to know what the probability of getting a 2 is, the sampling operation may return 0.34 or something like that.  The reason I ask is that I'm trying to implement an action selection policy for a reinforcement learning method based on a research paper. From what I gather from the paper, the author is able to sample the distribution by "mapping the uniform distribution U[0,1] through cumulative probability density functions obtained by adaptive numerical integration". From this he then samples the transition probabilities for each trial...  I would be grateful for any info on this...  Thanks in advance


Uniform convergence of $\lim_{n \to \infty} \frac{nx}{1 + n^2x^2} \text{ where } 0 \le x \le 1$

Prepering to second exam in Calculus 2, and I remember this question from the first exam that I fell on:  Let $f_n(x)$ be the function sequence $\{\frac{nx}{1 + n^2x^2}\}_{n=1}^\infty$ Let $f(x)$ be the limit function such that $\lim_{n \to \infty} \frac{nx}{1 + n^2x^2}$ convergences to. Does $f_n(x)$ convergents uniformly to $f(x)$?  As for the answers, the answer is no. Can you please explain me why? Thanks in advance!


Can I use the ubuntu font in a commercial logo design?

I've been looking into using the Ubuntu typeface for a logo.  The logo is for a web site unrelated to ubuntu and open source software.  I'm wondering whether the license allows this, and if so, whether there are any limitations?


I am using QGIS 2.18.9 and I have a problem. I dissolved a small map with about 1000 small regions into one big polygon, with Vector->geoprocessing tools->dissolve.    But after the dissolving there are little dots everywhere. After zooming in I found that these are all little holes in the layer.   Now I want the dissolved layer to not have any holes. Is there an easy way to do that?


For the past day's I have been logging on every day on  Today I logged in again only to find out my consecutive days were reset back to 1.  My other accounts didn't reset.   How is this possible? I am 100% sure I was logged yesterday.


Where can I find how many audits I passed or failed?

I was wondering if there is a way to know how many audits I failed and how many I passed on Stack Overflow?


I understand that we calculate a posterior belief by updating our prior belief with the information from given data, like  $$ p(\theta|y_1,...,y_n)\propto p(y_1,...,y_n|\theta)p(\theta)$$  But I dont fully understand the concept of a predictive distribution (the distribution of $\tilde{Y}$ having observed $\{Y_1=y_1,...,Y_n=y_n\}$ from the population.  What is the difference between a posterior distribution and a predictive distribution?


Where did the Wizarding World think Harry was?

After the death of Lord Voldemort, Harry was taken to the Dursleys and became known as "The Boy Who Lived".  We know that the Wizarding World found out  that Voldemort was dead and undoubtedly it was Dumbledore that advised people that Harry had somehow survived the attack and caused Voldemort's death. According to Snape (in HP:HBP) there were even persistent rumours that Harry was a powerful Dark Wizard in the making until he turned up at Hogwarts a decade later.  My question is : Where did the Wizarding World think Harry was for the intervening 10 years?


Can I pass a System.Net.MailMessage to a WCF service?

I'd like to setup a WCF service to send emails. The System.Net.MailMessage doesn't seem to be serializable, and cannot be passed in a [DataContract]  The error I receive is      Type 'System.Net.Mail.MailAddress'   cannot be serialized. Consider marking   it with the DataContractAttribute   Any suggestions?


"I have been 'verb-ing'" vs. "I had been 'verb-ing'"

A. I have been studying English for one year. B. I had been studying English for one year.  Could one who hears those sentences argue that "A" case implies "and I am still studying it" whereas "B" case implies "and I am no longer studying it"? If so, how are different in time frame the following sentences?  I worked in Colombia for ten years when the manager sent me to Italy.  I have been working in Colombia for ten years when the manager sent me to Italy.  I had been working in Colombia for ten years when the manager sent me to Italy.   Please, consider that the real situation is that I worked in Colombia from 1963 to 1973 and, for some reason, 1, 2 or 3 must  be written today. However I'm under the impression that only the "3" case is grammatical or, in any case, correct in reference to the real situation, although "1" case seems to be salvageable deleting the preposition "for". Can anybody explain?


How do I extract all the external links of a web page?

How do I extract all the external links of a web page and save them to a file?  If there is any command line tools that would be great.  It was quite the same question , and the answer worked gracefully for the google.com, but for some reason it doesn't work with e.g. youtube. I'll explain: let's take for example . If I try to run   lynx -dump http://www.youtube.com/playlist?list=PLAA9A2EFA0E3A2039&feature=plcp | awk '/http/{print $2}' | grep watch > links.txt   then it, unlike using it on google.com firstly executes lynx's dump, followed by giving control to awk ( for some reason with empty input ), and finally writes nothing to the file links.txt. Only after that it displays non-filtered dump of lynx, without a possibility to transfer it elsewhere.  Thank you in advance!


How do I conditionally create a stored procedure in SQL Server?

As part of my integration strategy, I have a few SQL scripts that run in order to update the database. The first thing all of these scripts do is check to see if they need to run, e.g.:  if @version <> @expects     begin         declare @error varchar(100);         set @error = 'Invalid version. Your version is ' + convert(varchar, @version) + '. This script expects version ' + convert(varchar, @expects) + '.';         raiserror(@error, 10, 1);     end else     begin         ...sql statements here...     end   Works great! Except if I need to add a stored procedure. The "create proc" command must be the only command in a batch of sql commands. Putting a "create proc" in my IF statement causes this error:   'CREATE/ALTER PROCEDURE' must be the first statement in a query batch.   Ouch! How do I put the CREATE PROC command in my script, and have it only execute if it needs to?


A question in Abstract Algebra about cosets

I tried to solve this problem but without success:  Let $H$ be a subgroup of a group $G$. Build an injective function from $G/H$ (the set of left cosets of $H$) to $H\setminus G$ (the set of right cosets of $H$). Note that $|G/H|=|H\setminus G|$.  I would like to get help with this question. Thanks.


Why is the speed of light in vacuum constant?

Are there any proof of the speed of light in vacuum being constant? All I hear is that light in vacuum travels at a constant speed because that's an observation and that it fits in a coherent theory with all sorts of other detailed observations. Is there no like mathematical proof or something or is it just purely based on observations/measurements and why is the speed the same for all observers? Please, try to give simple and meticulous explanations since I'm not the best at physics and might have a hard time understanding what you mean otherwise.


Without using SpamAssasin, or similar, what are your best tips for preventing spam.  Please try and provide config examples :D


I would like to close some view windows that I opened accidentally.  See the image below:    Edit: another note: I tried searching for the solution, but only found things like "Join Area", which don't seem to work in this situation.


I Want to Make my Swap partition bigger, I didn't know exactly what swap was until I looked it up, So I set my swap partition as only 100 megabytes, I then learned that that is positively puny compared to what is supposed to be there for my computers specs! So I have only used about 13 out of 300 gigabytes on my main partition. So I want to shrink my my main partition and enlarge my swap partition. Here is what I have already tried, I am Using Gparted if there is a partitioning tool that you would rather me use, please suggest it, but if it will do the exact same as Gparted, I would rather just stick with it,   Open Gparted, and type in my administrator password Click on my main partition "/"  Try to shrink, But wont let me shrink or enlarge   I have also tried deleting my swap then trying to enlarge my Main just to see if it will resize, but it still wont enlarge. Please Help!!  For the people who labeled my question duplicate: The question you labeled mine as a duplicate of does not address my problem, I specifically want to know how to resize my main and add to swap, not learn how to partition all together


I have an Acer C720, with a 64 gb SSD,  in which I would like to install Ubuntu. But I don't want the "crouton" version. If I follow the directions from here () will I get a "real" version of Ubuntu? If not how should I proceed?  Thanks


id command doesn't show all user's groups

I did a usermod to add the current user user in a group, but when I run id -Gn it only shows the main user's group:  [user@computer ~]$ id -Gn  user   But when I specify the user, it works normally:  [user@computer ~]$ id -Gn user user newgroup   Do you have an idea why it works like it? Am I missing something concerning the groups management in UNIX?


Pycharm cannot find reference 'SearchCursor' in 'arcpy.da'

Whenever I try to use a search cursor from arcpy in pycharm, I get this unresolved reference error. I should note that it was working fine earlier in the night, I have no idea what happened.     I've tried everything in this Q&A already:     Other arcpy functions seem to work fine. I've also tried restarting computer and reinstalling pycharm. I can use the search cursor when I use IDLE.


Is there a good chance that gravitational waves will be detected in the next years?  Theoretical estimates on the size of the effect and the sensitivity of the newest detectors should permit a forecast on this.


Special linear algebra over finite field with characteristic 3

I have problem to solve Exercise 5.6 in a book named "Introduction to Lie algebra and Representation Theory" from Humphreys. I want to show that special linear algebra $ \mathfrak sl (3, F)$ modulo its center is semisimple, but its killing form is nondegenerate, where field $F$ has characteristic 3. My attempt is to consider basis of $ \mathfrak sl (3, F)$ and calculate arbitrary solvable ideal of given lie algebra. However, this does not go well. May I ask for a help?


$f$ is $\mu$-integrable $\Leftrightarrow \, \sum_{n\in\mathbb{Z}}2^n\mu(\{x\in X\mid2^n<f(x)\leq 2^{n+1}\})$

Let $(X, \mathcal{A}, \mu)$ be a measurable space and $f:X \rightarrow[0,\infty[$ a measurable function $f$ is $\mu$-integrable iif... $$\sum_{n\in\mathbb{Z}}2^n\mu(\{x\in X\mid2^n<f(x)\leq 2^{n+1}\})$$ is convergent  I thought about it this way... $f$ is $\mu$-integrable and $f \geq 0$ $\Rightarrow \,\int_X f \,d\mu < \infty$ Because $f$ is measurable $\Rightarrow f = \sum_{i=1} \alpha_i \mathbf{1}_{A_i}$  where $A_i \in \mathcal{A}$ and $\mathbf{1}$ is the indicator function. We also know that the Integral of $f$ is therefore... $\int f\, d\mu = \sum_{i=1} \alpha_i \mu(A_i) < \infty$ Now it gets a bit tricky. I'm assuming $Z:=\{x\in X\mid2^n<f(x)\leq 2^{n+1}\} \in \mathcal{A}$, otherwise the notation wouldn't make much sense. Then I think I'm practically done. Since $2^n$ is a lower bound for the function-values, we can assume, that $\alpha_i \geq 2^n$ for that set. Therefore... $$\sum_{n\in\mathbb{Z}}2^n\mu(\{x\in X\mid2^n<f(x)\leq 2^{n+1}\})\leq \sum_{i=1} \alpha_i \mu(A_n)<\infty$$ should be true, because $Z$ is also in the RHS of the inequality. I'm assuming my thinking is incorrect, but that's the best I can come up with right now. Hoping for any helpful tips how to solve that. Thanks in advance.


Null or default comparison of generic argument in C#

I have a generic method defined like this:  public void MyMethod<T>(T myArgument)   The first thing I want to do is check if the value of myArgument is the default value for that type, something like this:  if (myArgument == default(T))   But this doesn't compile because I haven't guaranteed that T will implement the == operator.  So I switched the code to this:  if (myArgument.Equals(default(T)))   Now this compiles, but will fail if myArgument is null, which is part of what I'm testing for.  I can add an explicit null check like this:  if (myArgument == null || myArgument.Equals(default(T)))   Now this feels redundant to me.  ReSharper is even suggesting that I change the myArgument == null part into myArgument == default(T) which is where I started.  Is there a better way to solve this problem?  I need to support both references types and value types.


How to implement georeferencing in Drupal?

I must make a website with geo-referenced content. And I would like to add POI and the possibility to download this POI for GPX, KML\KMZ (Google Earth), etc.  Any tips or ideas to implement this somehow?  PS: if the above is not clear enough, have a look at  or  (the idea is building a website with such contents).


Google Chrome has installed in Dutch language (using Windows 10)

Since the language is one that I don't understand, and the layout of the 'settings' seems  different to the proposed answer- I cannot guess where to go next. I have changes the language in some individual pages eg Web Store, but it goes back to Dutch on restarting the browser!


Trig Derivatives - Can They Be Explained Intuitively but Non-Geometrically?

Thanks for reading.  Every time I look for "intuitive" explanations of why trig derivatives and integrals are what they are, I always get graphics like the following:    However, Sines and Cosines show up in mathematical topics which aren't always geometric by nature...even if perhaps connections to triangles and circles can always be found.  Are there ways to explain, still intuitively (by intuitive I mean explanations that "click," I don't mean hand-wavy...I hope that makes sense), but non-geometrically, why the derivative of sine is cosine (and why the integral of cosine is sine, derivative of cosine is -sine, etc...)?  Thank you!


Why are there so many close votes to review and so few of the others?

In the SO Review page , I see the following stats for questions awaiting review:   Close votes:  51.8k (and rising) Suggested edits: 10 (fluctuates, but rarely goes above 20) Everything else: 0 (occasionally see some if you're really lucky)   My question is: Why?  Why are there so many close votes waiting for review? Close votes should expire after four days. And even if there's a good reason for them hanging on longer (ie they're not being viewed), there surely has to be a cut-off eventually after which they can be safely dropped?  And yes, I saw , which is asking basically the same thing. But that was several months ago, and it seems that the queue has hardly moved since then. It seems to me that there's a massive backlog that will never be cleared, and apparently will never expire either. That's not good.  And on the flip side, why are there hardly ever any new user posts or low quality posts to review -- there are always new users posting things, and I recall before this new review system was launched that the list of low quality posts to review was always pretty big.


at least one element fixed by all the group

$G$ is a p-group and $S$ is a set that $G$ acts on. p does not divide $|S|$. Why is there at least one element $a\in S$ such that $|O(a)|=1$, or in other words, $G_a=G$?  I tried to ask this question yesterday but did not word it right, so the one who helped me claim that this part is clearly true and I really do not understand why, and I couldn't get a straight answer for the past day.   Any of you are welcome to vote to delete this question (after some discussion with me about the problem I hope), but I just really want to know why it is "clearly true, because I still couldn't reason it right.


Set Update Manager to install to sites/all/modules/contrib?

I am able to use Update Manager to install new modules, instead of having to manually upload them. I previously put everything in sites/all/modules, but now have reorganized my modules into sites/all/modules/contrib and sites/all/modules/custom (for the modules I write or modify).  However, Update Manager is still installing new modules in sites/all/modules. Is it possible to tell Update Manager to install new modules in sites/all/modules/contrib instead? I looked for a setting somewhere, but can't find one (D7).


I am writing to save others time if they get into an issue and end up in Emergency Mode due to a corrupt entry in /etc/fstab.    This has already been asked, but I couldn't get the resolution quickly and had to dig a lot.


Blown out blue/red light making photos look out of focus

I've only recently started taking photos and got into shooting concerts in a small venue that has neither a pit, nor proper lighting. All they use is some kind of simple LED array.  The thing is nobody wants to operate the lights and they tend to be too strong (I think).    Sometimes it's just like that for 15 mins or something... Photos seem to be out of focus, but I'm 99% sure they are (you can never be sure with a Nikon D7000, though).  These were shot using the 35mm DX and then cropped. Sometimes you can get something out of these kind of photos in LR (luminance, clarity), but it mostly looks like you f*ed up...  What can I do about it, except waiting for the light to change?   Underexposing will lead to heavier post-processing, which is unacceptable and B&W looks ugly and not sharp...  Of course not every photo has to be a keeper, nonetheless I'd like to know how to deal with that.  edit to explain(...)  Not exactly a duplicate, because I'm not using aperture priority so metering problems don't apply here. Different colour of light (green) + same settings, and the photo is fine. I'm aware of light waves having different lengths, etc. Just asking whether I should underexpose or it's just the way it is.


piping pwd to an executable as an argument

So I have an alias for "sublime text"  and very often I need to open a file or a folder right from the terminal, easy for a file:  subl myfile.html   and for a folder  subl /Users/me   But how can I use 'pwd' command to open current directory in sublime? Is there a way to pipe it in?


Central limit theorem and the law of large numbers

I have a very beginner's question regarding the Central Limit Theorem (CLT):  I am aware that the CLT states that a mean of i.i.d. random variables is approximately normal distributed (for $n \to \infty$, where $n$ is the index of the summands) or the standardized random variable would have a standard normal distribution.  Now the Law of Large Number states roughly speaking that the mean of i.i.d random variables converges (in probability or almost surely) to their expected value.  What I don't understand is: If, as the CLT states, the mean is approximately normally distributed, how then can it also converge to the expected value at the same time?   Convergence would imply for me that with time the probability that the mean takes a value which is not the expected value is almost zero, hence the distribution would not really be a normal but almost zero everywhere except at the expected value.  Any explanation is welcome.


Show some indication that account is banned from asking new questions

It would be nice if we could see somehow that someone is getting the infamous "Sorry, we are no longer accepting questions from this account" message when trying to ask new question, same way that we can see when someone is suspended when viewing the user profile.  It can appear as the same red bar as in the suspended account, or something else.. maybe only via the moderation tools for 10K+ members.  Right now when someone ask  we can only assume this is the case but can't know for sure.  Edit: as we can all clearly see, there is a steady rise in programming questions posted here on Meta by users who are getting banned from asking questions on the main site. While we can handle this easily, it would still be useful to show some indication that the user is question banned on the main site even if just so that people won't waste time trying to offer guidance to those users.


Can't install any packages on Ubuntu 16.04

I have just bought a new digital ocean Ubuntu droplet and configured it as an Apache server but when I was installing phpmyadmin package my ssh session suddenly shut down and so the download and install was interrupted. Since then whenever I try to download anything using apt i get this error  The following packages have unmet dependencies:  sendmail : Depends: sendmail-base but it is not going to be installed             Depends: sendmail-bin but it is not going to be installed             Depends: sendmail-cf but it is not going to be installed             Depends: sensible-mda but it is not going to be installed E: Unable to correct problems, you have held broken packages.   I tried to install aptitude to fix this problem but then i received this error   Package aptitude is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'aptitude' has no installation candidate   I tried all the commands of  apt-get update , apt-get upgrade  I would be glad to know how to solve this as I really need to install send mail  My question isn't like the others as it is asking about the version 16.04 of Ubuntu and i tried all the possible answers


I installed Ubuntu out of a USB stick and created a dual boot in my windows 8 computer.  Now I was informed to use another computer for Ubuntu's purpose and I want to undo what I've done.  Is there a quick way to do it without hurting my windows 8 environment?


I can take the cats that are already non-ocelot (Cats in villages or witch hut) but when I try to tame the ocelots I stay still, and they come to me and I feed them like normal but after 2-3 fish, it shows hearts but the ocelot stayed an ocelot? I tried again with another and same thing.


"SO questions are penalized" in the hot list - how does that work, can it be done for other site(s)?

Shog explained :     SO questions are penalized... if your goal is to get more SO questions into the list, you have a bit of a hump to climb.   How is this achieved?  Or, to be more precise, is it technically possible to set up similar "penalty" for some other site? If , what is needed in order to  ask for similar protection penalty to be established for a particular site?


This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. See  for more information.   What games are available that run natively on Ubuntu?  Please limit one game per answer - and include why you enjoy the game.


C#: what's the equivalent of SQL "LIKE" feature?

My example code:  public static bool StringSearchHit(string keyWord, params string[] targetArray) {     foreach (string targetItem in targetArray)     {         if (targetItem.IndexOf(keyWord, StringComparison.InvariantCultureIgnoreCase) >= 0)             return true;     }     return false; }   The problem I have: the LIKE operator in SQL is not just string.Contain() or string.IndexOf(), there are "culture character similarity" in it (I don't know how to call it).   Example: when I search using LIKE '%pokemon%', the "Pokémon" will also be included. The character "é" will be considered as similar to "e".  Same for some German characters. The special characters "ä ö ü" will also be considered "like" "a o u" in SQL.  My goal: when the keyWord is "aou", and one of the targetArray has "äöü", it will also return true.  Is there any equivalent of this in c#?  Edit: thanks for pointing out about another post:     That is the correct direction, but in another issue, it's "compare", not "contain". How to do similar thing in "string.Contain"?  Edit 2: Thanks for the correct answer:    Tried this solution, "Pokémon" can be searched using "Pokemon", and "Æon Flux" can be searched using "aeon".  Case close and marked as duplicate.


Help with normalising data that has A LOT of 0s

I recently am analysing my results (behavioural, observation-based data), and I realised that my data are non-normal. No problem, this happens in behavioural data a lot, and I thought I just needed to do non-parametric tests instead. Turns out, my observational data are like multiple dependent variables (e.g. I recorded different courtship rituals of 1 individual in a 1h observational period/ continuous) against 1 independent variable (treatment/categorical). Hence, MANOVA seemed like the correct stats test to use.  Well, given that my data are all NON-NORMAL (in addition to no equal variances), I cannot use MANOVA. It violates most of its assumptions. I do not know of any non-parametric version of MANOVA either. The other issue comes with transformations as my data has a LOT of 0s. They are not due to measurement errors or outliers where I can dismiss them - they are true observations and are important to keep. I've tried log-transforming my data (i.e. log(y+1), so that 0 can be transformed into 0, increasing my constant to >1 etc), cube root transformation, square root transformations but my data is still non-normal.   Any idea how to overcome this non-normality issue? I need to do MANOVA, or something like that, in which I can compare multiple dependent, continuous variables against 1 categorical independent variable at one go.


Attempting to get my terminal to play a specific ogg file while I type

My end game is to get my computer to make all of the sounds from my all time favorite video game from the 90's. I've already found the ogg file but now I want it to play every single time I type ANYTHING in the terminal.   For example: "fjeocjrigfjrig" would play the specified sound 14 times as I type. The clip for this is only about .3 seconds long. Is this possible?  I'd only like for this to happen while in the terminal. My google-fu turned up with nada.


3 questions about Algebraic Geometry and Zariski topology

I've read this exercise on my book, but I don't know how to prove it... Can someone help me?  Let X $\subseteq \mathbb{A}^n$ be an algebraic set, and $f, g:X\rightarrow k$ two regular functions.  a) If we see $f$ as an application $X \rightarrow \mathbb{A}^1(k)$, prove that $f$ is continuous in the Zariski topology.  b) If $X$ is irreducible and an open $U \subseteq X$ exists such that $f_{|U} = g_{|U}$, prove that $f=g$.  c) Give an example of $X, f$ and $g$ such that $f \neq g$ but $f_{|U} = g_{|U}$ in an open $U \subseteq X$.  Thank you!  For b) I have been able to prove that:  Let E be the subset where $f = g$ so E is closed (Why? I know that $E = (f,g)^{-1}(\Delta_{k})$ but... why is $(\Delta_{k})$ closed?). So $U \subseteq E \Rightarrow \bar{U} \subseteq \bar{E}=E$ (beacuse E is closed) $\Rightarrow X \subseteq E$, because $\bar{U}=X \Rightarrow E = X$ and $f=g$ in X.


Object turning flat grey in rendered view

hello guys. I'm having problem using render mode on blender on any file I've. The models are not displayed correctly on render mode, not on this file,the problem persist on any file. Cycles or Evee the problem persist Hardware specification GPU AMD Radeon (TM) R9 380 Series CPU Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz 4 Cores what could be causing this troubles?


'that' + (pro)noun + infinitive: what grammar is behind such construct?

While reading a technical book, I stumbled upon the following sentence:     It is important [that all Java programmers be fully versed in, and comfortable with, the traditional approach].   For me, it's kinda counterintuitive to see Java programmers be here. I would understand for Java programmers to be or that Java programmers are, but not the existing variant.  Since it’s far from the first time I have seen such a construct, obviously there must be some grammatical explanation to it. I only wish someone could enlighten me about the exact rules being used here.


CBC with random prefix but no IV - secure?

I'm looking at a datagram-based protocol that encrypts a payload. The payload is encrypted with AES or blowfish in CBC mode, and the result is then authenticated with a HMAC.  To save space, the protocol uses a zero IV, but prepends a special prefix to the data before encryption.  The prefix consists of 12 random bytes, followed by a unique sequence number that isn't reused for the same key.  In summary, the datagram payload basically looks like this:  HMAC(12+ bytes) CBC-ENCRYPT (IV=0, RANDOM(12 bytes) SEQUENCE(4 bytes) REAL_DATA)  My question is, is there an obvious flaw to this construct? As I see it, it basically is like normal CBC, but instead of a fully random IV, it uses ECB-ENCRYPT(random + sequence) as (effective) IV.


Best way to find all factors of a given number

All numbers that divide evenly into x.  I put in 4 it returns: 4, 2, 1  edit: I know it sounds homeworky.  I'm writing a little app to populate some product tables with semi random test data.  Two of the properties are ItemMaximum and Item Multiplier.  I need to make sure that the multiplier does not create an illogical situation where buying 1 more item would put the order over the maximum allowed.  Thus the factors will give a list of valid values for my test data.  edit++: This is what I went with after all the help from everyone.  Thanks again!  edit#: I wrote 3 different versions to see which I liked better and tested them against factoring small numbers and very large numbers.  I'll paste the results.  static IEnumerable<int> GetFactors2(int n) {     return from a in Enumerable.Range(1, n)                   where n % a == 0                   select a;                       }  private IEnumerable<int> GetFactors3(int x) {                 for (int factor = 1; factor * factor <= x; factor++)     {         if (x % factor == 0)         {             yield return factor;             if (factor * factor != x)                 yield return x / factor;         }     } }  private IEnumerable<int> GetFactors1(int x) {     int max = (int)Math.Ceiling(Math.Sqrt(x));     for (int factor = 1; factor < max; factor++)     {         if(x % factor == 0)         {             yield return factor;             if(factor != max)                 yield return x / factor;         }     } }   In ticks. When factoring the number 20, 5 times each:   GetFactors1-5,445,881 GetFactors2-4,308,234 GetFactors3-2,913,659       When factoring the number 20000, 5 times each:   GetFactors1-5,644,457 GetFactors2-12,117,938 GetFactors3-3,108,182


Should first and last name be formatted?

When collecting first and last name from users, should the name be formatted if it will be shown to the user again?  Example: BILL is formatted to Bill  It seem almost impossible to account for all the variations on names.


How to format SQL tables in a Stack Overflow post?

I want to format an SQL table the right way in a Stack Overflow question.  ID Name  1 Tom  I know the example above is not the right way. I even tried an HTML table approach, but it's still wrong. Please help, because I need to include SQL tables later...


https://stackoverflow.com/conduct displays 404 - Linked in the blog

The code of conduct announcement blog just went out, yet the link to the code of conduct page in it yields a 404 - page not found.  Seems like a bug.    This is on latest version of google chrome / windows 8.1


Confusion in proof for writing Poincares series in terms of Kloosterman sum

I am currently self reading " Spectral theory of Riemann zeta function" by Yoichi Motohashi. The example is in first chapter and of poincare series. I am not able to justify from 1.1.5 to the next line. Actually I don't know what does mean by classifying summands according to h (mod l). Any help/Hint would be appreciated. I am stuck here since yesterday.


I usually hear people incorrectly using are/is such as in the sentences "I don't know what is that" or "Do you know what are the examples?" What is the correct use of grammar called in these instances? Some sort of agreement?


when use type inference? we can always use VAR?

The type inference VAR,serves only to be recognized by the program only if he has to go to replace "int "string" etc.? If yes,would it not be better to always use VAR?


While jumping in a high speed train why we fall on same place?

while we jump inside a high speed train why do we fall on the exact place? as train is in high speed and we are jumping so we should fall backside. but this doesn't happen why?