Why do ice cubes stick together or to the edges of a drinking glass?

I was drinking iced-water from a drinking glass (made of glass) at a restaurant yesterday when I was taking a drink, I noticed that there is very little ice water coming out and then suddenly, the ice water mixture comes crashing down. With my open mouth overfilled with ice water, my shirt gets wet – I hate when this happens. After drying myself off, I started thinking why this does happen:   How does ice that starts off loose and separated in water fuse together to form one large clump? What causes the ice-water mixture to stop flowing momentarily and then suddenly starting flowing again? Is it that the ice fuses together in the glass and forms one large clump, and then the friction with the edges builds a "dam-like" situation? Or are there individual pieces of ice fusing with the edges of the drinking glass damming-up the ice?


Science-fiction short story where space navy wanted hospital ships and settlers had guns mounted everywhere

I remember reading a short story where the official space navy of the “Golden Empire” would only fight if hospital ships were close by, so they could be picked up and treated. They had to defend their home planet against some settlers from outer asteroids. The settlers welded guns onto every possible part of their ships, disorganized and messy compared to the Imperial ships. One settler ship blew up two navy ships, and then  kamikaze'd into the hospital ship, blowing it up as it exploded. All the Empire ships surrendered, and the Empire fell.  There was an Imperial historian, laughing as their city burned. It was because he realized the same thing would happen to the conquerors, later, as they developed an empire of their own.  I'm not sure when, or where, this was published. I've read a lot of science fiction over the years.  This was a story about centralized, decaying power and the virility of the frontier.


Disclaimer: I've already completed the game, so I know what to expect in the final mission.  That said, the fight right at the end was (almost) a complete balls-up. I managed to      kill the first 2 avatars, but then I got pinned down in the open area after the bridge by the constant waves of reinforcements. In the end I took the last avatar down after exhausting all my grenades and with everyone in the squad wounded.   And that was just on Rookie.  So, I'm wondering what the best approach is for that fight, for my second playthrough on Veteran. Should I charge in and try to eliminate each boss as fast as possible, or draw them out on to the bridge? What squad composition would people recommend?


How do I add n number of input fields depending on a passed value?

I'm trying to create a dynamic number of HTML input text fields, where the number comes posted from another form. But Flask interprets the form number 10 as 1 0, i.e. 2 (string length).  The first form:  <form action="/new_vocals" method="post">   <input type="text" name="count">   <input type="submit">   The Flask app route:  @app.route("/new_vocals", methods=['POST', 'GET']) def new_vocals(): voc_count = request.form['count'] return render_template("new_vocals.html", count=voc_count)   Trying to use voc_count in a for loop, I get 2 input types with the value 10, 3 with 100 and so on.  There has to be a way to get Flask to interpret 10 as a string?


Why does the Newton-Raphson method not converge for some functions?

$f(x)=2x^2-x^3-2$. This is a cubic type graph as shown.  The real root of this graph is $(-0.839,0)$.  So, the question is to use Newton's approximation method twice to approximate a solution to this $f(x)$.  I use an initial starting value of $x_0=1$. My first approximation is $x_1=2$, and my second one is $x_2=1.5$. I seem to not move any closer to the real solution as I keep iterating through the method.  Am I misunderstanding how to use this approximation?  Is the issue that my first guess was too far from the actual solution?


So this is my first try with cycles and I was wondering what can I do to make the image clearer?


Why does Grover's Diffusion Operator have the word "diffusion" in its name?

Where do I see the diffusion in the Grovers operator? I would think there should be an analogy to classical diffusion but I am not able to see the correspondence.


What approach should I take to find the oldest question on a stack exchange site?

How do I find the oldest questions (such as the first asked question by anyone) on a stack exchange site.  Was having a look through a users profile on Ask Different and had the idea to see who asked the first question there.  Is there a hack?  Edit: Fair point directing me to the last page on the questions page. Many questions are added per second on SO so getting the last one on the last page is fiddly and I figured there might be another way. The best I can get with my access on SO, telling by a pretty URL, is question 4 for C#on setting form opacity:   As the answers pointed out I don't have the points to see all answers such as Joel Spolsky's .


Let $q_1,q_2,q_3,q_4$ be orthonormal vectors in $\mathbb{R}^4$,$z_1,z_2,...,z_6$ orthonormal vectors in $\mathbb{R}^6$ and $A=z_1q_1^T + z_2q_2^T$.  a) Find the base and dimension of fundamental subspaces of matrix A  b) Using the results given by a) find the general solution for $Ax - z_1$.  Any hint would be appreciated.


Why does WMI Provider Host (WmiPrvSE.exe) keep spiking my CPU?

I generally keep my laptop on 24x7, and at the end of the day it's really annoying to have my thighs burnt because over overheating.   The overheating seems to be a result of WMI Provider Host (WmiPrvSE.exe) spiking the CPU utilization to 25% every few minutes.  Why does this happen?  I have an HP Envy 14 (with the HP bundled crap) running on Windows 7 Home Premium.  (Note: Based on @nhinkle's , it seems that HP Wireless Manager might be the culprit, is there any way to confirm this?)     This question was a .   Read the Feb 28, 2011  for more details or  Question of the Week.


A friend recently asked me the question, "If electrons have a negative charge and the nuclei of atoms have a positive charge, why don't electrons simply collapse into the nucleus and sit on it?".  I tried to direct him to things such as the Pauli Exclusion Principle or Heisenberg's Uncertainty Principle, calling upon him to see an electron as a space of probability densities rather than a particle, but ultimately neither did he feel satisfied nor could I give a satisfactory answer (considering especially my limited knowledge of atomic physics).  Could you give an answer for me and for him, in some detail, that explains both intuitively and with some depth why this is?


Let $E$ be a finite extension of $F$ and suppose that $[E:F] = p$ where $p$ is prime. Prove that $E$ is a simple extension of $F$.  I really don't know where to start. Thanks in advance.


Am I the only one who feels like the logo is slightly misaligned? I think the first angled bar should be moved a little bit to the right, so that both corners are aligned. (pink)  I also found out that the padding between the container and the first bar is uneven as well. (blue)    Don't get me wrong, I love the concept of the logo, but I feel that it's a little bit off. Did anyone else notice this?


If $A$ is a semilocal ring and $f:A\rightarrow B$ is a surjective homomorphism, then $f(\operatorname{rad}A)=\operatorname{rad}B$.   I know that if $A$ is a semilocal ring and if $I_{1},\dots, I_{n}$ are all of its maximal ideals, then $\operatorname{rad}A=I_{1}\cdots I_{n}=I_{1}\cap\cdots\cap I_{n}$. Let $y\in\operatorname{rad}B$, then there is $x\in A$ such that $f(x)=y$. I would like to show that $x\in\operatorname{rad}A$.  Any hint?


Erase vector element from vector of objects by value

I have a c++ vector of student objects with each object having an ID(string), name (string) and age(int).  std::vector<student> myVector;   Lets say the vector looks like this     [{"1", "Tom", 12}, {"2", "David", 10}, {"3", "Adam", 15}, {"4", "Jill", 20}]   Is there any way I can delete an object in the vector using the student Name like:     myVector.deleteObjectWithName(David)   such that my remaining vector is now     [{"1", "Tom", 12}, {"3", "Adam", 15}, {"4", "Jill", 20}]


What language was used to write Rust compiler?

94% of Rust compiler was written in Rust. So I can't understand how is it possible? Because for compiling rustc you already must have some rust compiler. Can someone explain how it works and how rust compiler was created?


What is the practical advantage of disk brakes over rim brakes?

Disk brakes are becomming more popular on bikes now, and I was just wondering what the advantage is of this type of brake over the older rim brakes.


How can I move all `marked` files to another directory in ranger?

When I select multiple files within ranger (using <Space> or V), how do I move these selected files to another directory?  I've tried to use dd and pp, but this only moves the file that's currently highlighted.


How to pinpoint the cause of a system crash?

I'm running Windows 7 SP1 64-bit. My system has been running great lately, but it crashed all of a sudden. I checked the system event logs and found this:     The computer has rebooted from a bugcheck.  The bugcheck was:   0x000000d1 (0x00001000000102fd, 0x0000000000000002,   0x0000000000000000, 0xfffff88010143afd). A dump was saved in:   C:\Windows\Minidump\052714-23010-01.dmp. Report Id: 052714-23010-01.   Here's a link to the file mentioned above:   Can those cryptic codes be deciphered somehow? How can I determine what caused this BSOD?


What is the use of reflection in Java/C# etc

I was just curious, why should we use  in the first place?  // Without reflection Foo foo = new Foo(); foo.hello();  // With reflection Class cls = Class.forName("Foo"); Object foo = cls.newInstance(); Method method = cls.getMethod("hello", null); method.invoke(foo, null);   We can simply create an object and call the class's method, but why do the same using forName, newInstance and getMthod functions?   To make everything dynamic?


Creating Elevation Profile from Line Shapefile of Contours using QGIS?

I have a line shapefile that contains contour lines. The attribute table of the shapefile has a field that gives the elevation of each line. I would like to draw a line across the contours and get an elevation profile. I found the Profile tool but it seems to require some sort of raster layer, and not my line shapefile layer (gives message "active layer is not a profilable layer"). It may be that I need to use some other plugin to convert my shapefile layer to the proper layer to use in the Profile tool.   Is there some sort of step-by-step tutorial on what plugins I need and how to convert a shapefile layer to the correct type of layer so that I can obtain an elevation profile by drawing a line across the contours?  Using QGIS 2.18.18


Need to understand why my Schengen visa was refused

I applied for a schengen visa, to attend some interviews in Germany. I am a doctor, and a recruiting agency is arranging all the interviews. They provided me with an invitation letter, stating they would pay for my accommodation and expenses in Germany.  I submitted this letter with other documents; I had hotel confirmation from booked.com.  My visa was rejected due to three reasons.   Justification for the purpose and conditions of the intended stay was not provided The information submitted regarding the justification for the purpose and conditions of the intended stay was not reliable No proof of accommodation   What does it mean - was my invitation letter not good, or was it that the company just stated they would pay for accommodation and did not actually provide the proof of accommodation?  I can get a detailed invitation letter stating where my interviews will be, and also proof of accommodation. Is there anything else required? I'm sure no company that invites a person would give me their bank statement.  Any input will help me a lot.


How can I find a cubic function from two known points $\left(50,30\right)$ and $\left(100,0\right)$ which are turning points, hence the gradient at these points is zero. My final function must be in the form  $\,\mathrm{F}\left(x\right) = A\left(x + a\right)\left(x + b\right)\left(x + c\right)$.  I already know that  (X+b)= (x-100) (X+c)=(x-100)  So I'm missing A and a  The graph will then be set with a domain so it flows smoothly in this graph   I need very clear steps on finding a graph that flows smoothly and ends up in this form :)   Thank you!


Permanently install an updating Ubuntu on USB drive

I do know that some utilities can create a persistent Ubuntu on a USB drive, but as far as I know these installations never update the kernel and driver installations are not possible.  So the question is: is it possible to have a full fledged, updating Ubuntu installation running on a USB drive? Creating this installation would happen from a Windows 10 UEFI computer.


Wrap Figure not supported inside the list

Good day!!. Here I faced challenges when using wrap figure insid the list. Please suggest me how to fix this.  MWE:  \documentclass{book}  \usepackage{wrapfig} \usepackage[no-math]{fontspec} \usepackage{graphicx,epstopdf}  \begin{document}   \begin{enumerate} \item How much energy does the electron gain as it moves from the negative plate to the positive plate?  \begin{wrapfigure}[12]{r}{12pc}% \caption{This is a sample Caption} \includegraphics{c01f002} \end{wrapfigure}  \item How much energy does the electron gain as it moves from the negative plate to the positive plate?  \item How fast will the electron be travelling when it hits the positive plate, if it left the negative plate with zero velocity?  \item How much energy does the electron gain as it moves from the negative plate to the positive plate?  \item How fast will the electron be travelling when it hits the positive plate, if it left the negative plate with zero velocity?  \item How much energy does the electron gain as it moves from the negative plate to the positive plate?  \item How fast will the electron be travelling when it hits the positive plate, if it left the negative plate with zero velocity?  \item How much energy does the electron gain as it moves from the negative plate to the positive plate? \end{enumerate}  \end{document}


How to create an Ubuntu distro from VirtualBox Ubuntu Image?

I have an UbuntuServer installed and filled with packages that I need, and it's ready for work.  Can I make a distro from VirtualBox image of UbuntuServer in to .iso installable file with all the packages that I have setted up?  EDITED: I am sking how to create a distro from Virtual Machine and not how to convert Physical Machine in to Virtual machine.


After installing Ubuntu 18.04 server on a VM, and then installing a couple of services, I have not a clue as to how to configure my network to be either static or DHCP.  There are so many posts, blogs, articles etc on how to configure network settings that I’ve not a clue as to what is “in control” of my network now.  People suggest various tools, such as nmcli (which isn’t installed by default).  Write changes to the head file, no the tail file.  It’s quite frustrating.  Use network manager, use systemmd, it’s all just a jumbled mess of different versions of Ubuntu over 15 years.  Trying to figure this out is like jumping into a Wikipedia rabbit hole.  There is just no end in site.    So are there “tells” as to what “system” is controlling my network settings?  ETA:  I’m trying to make sure I’m using static ip instead of dhcp.


I am beginners to LaTeX and I have been trying to learn Tikz & PSTricks for graphics.  My Question is: Is there any other software available in which we can draw our desirable figures (like graphs of equations, all mathematics geometric figures and etc.) and  which help us to generate codes for figure?


How to put GeoServer layers behind authentication?

I want to publish map layers using OpenLayers and GeoServer. While this is easy enough to set up, I'm a bit lost when it comes to authentication possibilities. What I want is to create different users that will, by logging in with their own user name and password, be directed to their own map window. How can this be securely done so that none of my users will be able to access each other's layers?  I have understood that it is quite easy to "hack" the setup by, for example, making queries to the GeoServer where one simply asks it to list all the available layers.  What are my options? I suppose apache could be of help when setting it up in my ubuntu server? Any tutorials on this subject?


I know that the implementation of C++ polymorphism is based on the vtable and vptr. But now I don't understand how the pointer of the base class get the vptr of the derived class. For example:  class Base {     int b; public:     virtual void f() {}     virtual void g() {} };  class Derived: public Base {     int d; public:     virtual void g() {} }; int main() {     Base *b = new Derived();     b->g(); }    In this case, why b can access the vtable of the derived class? If the derived class inherits more than one base class and the derived class overrides the virtual functions of these base classes, then there will be multiple vptr in the derived class.  Derived *d = new Derived(); Base1 *b1 = d; Base2 *b2 = d; Base3 *b3 = d;   So how do these base class pointers get vptr and offset in the vtable?


Recently my question got labeled as - 'Post is related to a rapidly changing event.'  who does decide such tags and labels ?


How to find max of amount of opportunity related to account?

I have a below requirement : I need to find maximum amount on related opportunities and to display on account. Ex: suppose I have account A1 and A1 have 5 opportunities with amount o1=>100 o2=>500 o3=>300 o4=>1000 o5=>50 on my account i should have max_opportunity_amount =1000.  I have written below trigger ,but  I am not sure what to do further  trigger maxOppAmountonAcc on Opportunity(after insert){      map<id,Opportunity> oppMap = new map<id,Opportunity> ();     set<Id> oppId = new set<Id>();     for(Opportunity o : Trigger.new)     {         oppMap.put(o.accountId,o);         oppId.add(o.id);     }       List<Account> accList = new List<Account>();      for(Account a : [Select id ,MaxOppAmount__c,(select id,max(amount)  from opportunities) from Account where id in : oppMap.keyset()])     {      }  }


Word for feeling extremely embarrassed for someone else

I am looking for a word that evokes embarrassment in oneself through others, for example, watching a really bad performance on stage, it might not necessarily involves the humiliation of one party in public, the party can also be oblivious to what he is doing, but evokes a sense of embarrassment upon observation by someone else.


Compare 2 strings without considering accents in Python

I would like to compare 2 strings and have True if the strings are identical, without considering the accents.   Example : I would like the following code to print 'Bonjour'  if 'séquoia' in 'Mon sequoia est vert':     print 'Bonjour'


Biblatex citations inside KOMA-script's dictum

I would like to use biblatex (specifically, biblatex-chicago) to cite an author inside the \dictum command of scrbook.  Here's my MWE, which produces some errors.  \documentclass{scrbook}  \usepackage{lipsum} \usepackage[authordate,backend=biber]{biblatex-chicago} \addbibresource{test.bib}  \begin{filecontents*}{test.bib} @book{Marshall1920,     title={Principles of Economics},     subtitle={An Introductory Volume},     author={Marshall, Alfred},     publisher={Macmillan and Co.},     location={London},     edition={8},     date={1920}} \end{filecontents*}  \begin{document} \renewcommand*{\dictumauthorformat}[1]{#1}     \setchapterpreamble[u]{\dictum[\textcite[][782]{Marshall1920}]{If we shut our eyes to realities we may construct an edifice of pure crystal by imaginations, that will grow side lights on real problems; and might conceivably be of interest to beings who had no economic problems like our own.}} \chapter{A chapter heading} \lipsum[1]  \printbibliography \end{document}   It also produces a missing font related warning, but I thought I would not modify the font for the sake of keeping the example as minimal as possible.  I would rather continue using \dictum rather than switching to package epigraph or something similar, if this is possible.


When I ran to Nvidia's website to download their 64bit Linux drivers, it downloaded a file named "NVIDIA-Linux-x86_64-319.49.run".  Since this wasn't a file extension I'd seen before, I assumed double clicking would do nothing (Incorrect; it actually tried opening it in a word processor which hilariously meets with a crashed word processor).  I installed new drivers through a terminal.  For future reference, however, assuming this is an archive, and clearly Nvidia expects everyone to be able to crack it open on command, how would I go about making the .run file actually be useful?  Was there a command to decompress it and install the drivers?  Was it a script and I just have no idea how to execute it?  (Very new to Linux; Ubuntu's my first attempt at running a distro since ...oh, RedHat 6.something.  Anyways, so much for context.)


How can I retrieve an item that was on a follower who died?

I married Lydia and gave her the  to hold, but later she died. I don't remember where she died and now I need the  to complete the  - do any of you know a way to find Lydia or the mask?


what exactly happened:  I have a Seagate 1 TB external hard disk.It was working fine till now.The problem started when I plugged it in my android phone and then back in my pc then simply it does not showup anywhere and :  It does not appear in file explorer   It does not appear in disk management   It is not listed in Diskpart command   It only appears in Device Manager under disk drives   It does not appear in BIOS  only makes sound when plugged and unplugged.  disk spins and light is also showing.   . What I already tried:   updated usb drivers.  used new cable also.  plugged in another pc  usb mass storage is also enabled in BIOS  no issue in any usb port  Anything else i can do?


Bash if statement with prepended character

I'm trying to understand a  that will stop when executed as root:  #!/usr/bin/env bash  if [ x"$(whoami)" = x"root" ]; then     echo "Error: don't run this script as root"     exit 1 fi   I have tested this and it works as intended even if I remove the x in the if statement. My question is why is the x in x"$(whoami)" and x"root" needed?


Jeep problem variant: cross the desert with as much fuel as possible

I'm dealing with the following variant of the well-known :     A 1000 mile wide desert needs to be crossed in a Jeep. The mileage is one mile / gallon and the Jeep can transport up to 1000 gallons of gas at any time. Fuel may be dropped off at any location in the desert and picked up later. There are 3000 gallons of gas in the base camp. How much fuel can the Jeep transport to the camp on the other side of desert?   So instead of "exploring" the desert or trying to drive as far as possible, the problem here is to transport as much fuel as possible for a given distance.  I've thought about reducing this problem to the well-studied ones, but I can't come up with anything that makes sense. I don't even know how to approach this.  Any pointers?


How do high traffic sites service more than 65535 TCP connections?

If there is a limit on the number of ports one machine can have and a socket can only bind to an unused port number, how do servers experiencing extremely high amounts (more than the max port number) of requests handle this? Is it just done by making the system distributed, i.e., many servers on many machines?


Movie about a man and a woman accelerated in time. The rest of the world was suspended in time

This is a movie I saw on TV in the mid to late sixties, so I’m not sure if it was a made for TV movie or if it was out in theater in the late 50’s or early 60’s.  I only remember bits and pieces of it.  What I remember is a man and a woman accelerated in time.  The rest of the world was either suspended in time or moving very slowly.  The man I believe was either a pilot, or humanoid alien, and his plane, or spaceship, looked like it was about to crash but was suspended in time a few feet above the ground.  I’m not sure if they were trying to do something to save the world or trying to save someone, but whatever they needed to do I think they only had an hour to do it before normal time resumed again.  I also remember a scene where they were going along a street and found a boy running out in front of a truck and would most likely be hit when normal time resumed.  They used the truck’s seat belt to tie the emergency brake on so the truck would stop when normal time resumed.  I have been waiting a long time to see if it would be on TV again, but no luck. I know it’s not much to go on, but I would appreciate any help on this.


Can someone explain me, why the following doesn't work: echo hello | echo -  Just for learning purposes (don't tell me to use something else and not "echo" or why do I need it), I want to understand why it's not working. I'm trying to pipe the result of the first echo to the second echo (through stdin). Why is it not working and what can I do to make it work?


Prove that $(a + 2b + 3c + 4d)a^a b^b c^c d^d < 1 $.

This is question from yesterday's IMO.  The real numbers $a$, $b$, $c$, $d$ are such that $a ≥ b ≥ c ≥ d > 0$ and $a + b + c + d = 1$. Prove that $$(a + 2b + 3c + 4d)a^a b^b c^cd^d < 1$$


How to declare constant values in class and still access them in bounded methods

I have a simple problem that I can solve, but I'd like to find a cleaner way to get to my point. Let me give an example:  class Example(object):      def __init__(self, number):         self.number = number         self.constant = 4.0      def mult(self):         return self.number * self.constant   So, I have a bound method to my class that is called mult. My problem is I would like to get the self.constant out of the __init__ part of the class as it would be independent from any instance of that class. I was thinking about something like:  class Example(object):      constant = 4.0      def __init__(self, number):         self.number = number      def mult(self):         return self.number * constant   which obviously doesn't work. I was reading lately on class methods, which appeared like a good hint, but the problem I get with that is that I can't refer to my self.number in my method.  Anybody with a good idea, beside fixing my mult method to return self.number * 4.0 (my real problem is a bit more complex than that).


Is there a faster way to get notified of new questions than RSS?

I wanted to use RSS to get notification of new questions. I set everything up only to be disappointed by the fact that there is a significant delay between the asking of a question and its being included in the feed. By significant I mean on the order of 5 minutes. For most questions I am interested in answering, the question has already been answered by the time I see it. It is not a matter of refreshing the feed too slowly. No matter how fast I refresh, I can see that there are questions that are not in the feed by manually refreshing the stackoverflow page in a browser. Even if I repeatedly refresh the feed, the new questions do no appear for sometimes more than 5 minutes.  Is there a faster alternative to RSS for seeing new questions (other than scraping the web page)?


I came across this site  and they post free high resolution pictures to use. I have a canon550D with the standard kit 18-55m and a 50mm lens. How are these high resolution pictures achieved? I use lightroom for some basic editing... any information or advice would be great.


Why is the gap between the translation and the last line of the gloss so wide in my interlinear gloss?

I notice if I take away some letters, the translation line goes to where it should be, but this big block of white space is pretty untenable. Ideas?    \documentclass[11pt,a4paper]{book}  \setcounter{secnumdepth}{4} \usepackage{gb4e} \usepackage{tipa} \usepackage{setspace} \usepackage[T1]{fontenc} \begin{document} \begin{exe} \ex \glll Jichax    Qamaqix lij parki,  aynacha,    amsta,  parki, q'awanaks,   khuyt'asis  sarawjchix. \\ \{jicha-x(a)    Qamaqi-x(a) lij(u)  parki   aynacha amsta   parki q'awa-nak(a)-_{c}$\oslash$-s(a)   khuy(u)-t'a-s(i)-s(a)   sara-wj(a)-ch(i)-i-x(a)\}    \\ now-\textsc{top}    Fox-\textsc{top}    all acclivity   declivity   ascent  acclivity ravine-\textsc{pl-acc-ad} whistle-\textsc{m}-\textsc{refl}-\textsc{subr} go-\textsc{bfr-cnj-3sim-top}\\ \glt `And so, Fox must've gone whistling on all the ascents, slopes, ascents, mountainsides, and even in the ravines.' \end{exe} \end{document}


When and when not to use activation function between input layer and hidden layer?

I am beginner to Neural Network and this question might be very basic and stupid. Expecting some intuitive answer.


How to swap the values of 2 parameters in method Java

i want to swap the values of 'a' and 'b' and to return their values. I tried void type but it didnt swap the values. Now im trying this but eclipse saying that i didnt use 'return'.  public class swap {     public static int swap(int a, int b) {         int temp = a;         a = b;         b = temp;         int[] array = { a, b };          for (int i = 0; i < array.length; i++) {             return array[i];         }      }      public static void main(String[] args) {         System.out.println(swap(10, 5));      }  }


Windows 10 File Explorer: Search in indexed locations include compressed archives

I use Windows 10 File Explorer and I want to search in indexed locations include compressed archives (zip). In File Explorer folder settings there is only "when searching non-indexed locations" > "include compressed archives"... Please, can you help me how to do it? Thanks, Jiri


I have these two URIs:  http://www.google.de/blank.gif  http://www.google.de/sub/  I want the relative path from http://www.google.de/sub/ to http://www.google.de/blank.gif so that the result is ../blank.gif  URI.relativize() does not work here :/  Thanks!


What is the watching order for Tenchi Muyo?

I need to know the watching order. I've been wanting to watch all of them for awhile but not unless it is in order.  What is the intended watching order?


We're working with somewhat large sets of data, around 15M - 35M records per DE, each row with 150+ attributes. What are some ways to optimize SQL queries when handling many records?  For an exaple, using intermediate DE's and SQL queries selecting TOP 50% from a DE with 14M records will still take approximately 21-27 minutes to run, meaning with any major data increase these queries will time out. Data flow is Synchonized DE -> Shared DE -> sub-BU DE per object.  Salesforce's  on optimizing Queries is really basic and not of use this time around. Here is as example Query SELECT TOP 50 PERCENT // attribute list // FROM Synchronized DE WHERE // conditions //  ORDER BY  // condition //


An example of nonzero ring $R$ with $R^m\cong R^n$, $m\neq n$

I'd like to find an example of a nonzero ring $R$ and positive integers $m,n$ with $m\neq n$ such that $R^m\cong R^n$ as $R$-modules.


How do I open 2 instances of the same file in notepad++ side by side with their own scrollbars in a single Notepad++ window?

I remember doing this a long time ago and have forgotten how I had done it. I like to do this when I have long html or php files to edit and I need part of the code from further down the file in a place nearer to the top, or when I want to compare different parts of the same file.  There was a way to do this without opening two instances of Notepad++ and when I clicked on save, it made the saved changes in both instances of the opened file (whereas if I have 2 Windows of Notepad++ opened simultaneously, it will prompt me to either update or not update the second opened instance if the first one was saved midway.)


I am planning on going out to Pakistan soon and I am wondering if I should bring my Xbox 360 for a friend that stays there,  Would the Pakistani games work on my Xbox 360?


Can't install gtk-3-dev: unable to correct problems, you have held broken packages

I'm on Ubuntu 19.04 and have been trying to install libgtk-3-dev, but getting the following error:  ~/Downloads/Software $ sudo apt install libgtk-3-dev Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libgtk-3-dev : Depends: libegl1-mesa-dev but it is not going to be installed                 Depends: libepoxy-dev (>= 1.0) but it is not going to be installed   I tried fixing with all the following:   sudo apt update && sudo apt upgrade (all good, no errors in output) sudo apt update --fix-missing (all good, no errors in output) sudo dpkg --configure -a (empty output, no errors) sudo aptitude install libgtk-3-dev (no errors, but package is not installed) Synaptic through UI (gives me the same error)   Nothing works. Any ideas what should I try next?


When I try to log in using Google on the Android app, I get a thin red heads up saying      'key' is not valid for passed 'access_token', token not found.


If I draw a line as follows:  \documentclass[article]{standalone} \usepackage{tikz} \usetikzlibrary{decorations.pathmorphing,calc,shapes,arrows,snakes,shapes.geometric,patterns,fadings} \begin{document} \begin{tikzpicture} \draw[very thick](0,0)--(1,0);   How can I draw the line so that the line starts as red but then fades into blue, I have tried  \documentclass[article]{standalone} \usepackage{tikz} \usetikzlibrary{decorations.pathmorphing,calc,shapes,arrows,snakes,shapes.geometric,patterns,fadings} \begin{document} \begin{tikzpicture} \draw[very thick,top color=red,bottom color=blue](0,0)--(1,0);   but it does not seem to do anything, any advice?


ksh:Get files created on specific date in directory

I want get the files that were created on specific date in a directory   > ll  total 36 -rw-rw-r--    1 tak      tak           212 Oct 08 07:06 name.log -rw-rw-r--    1 tak      tak           494 Oct 09 09:24 rep.083011 -rw-rw-r--    1 tak      tak           494 Oct 08 05:27 rep.083221 -rwxrwxr-x    1 tak      tak           914 Oct 09 09:29 names.ksh -rw-rw-r--    1 tak      tak           331 Oct 08 09:28 report_091020130928.txt -rw-rw-r--    1 tak      tak           331 Oct 09 12:00 report_091020131200.txt drwxrwxr-x    2 tak      tak          2048 Oct 08 08:44 error -rwxrwxr-x    1 tak      tak             2 Oct 09 08:36 sample.ksh -rw-rw-r--    1 tak      tak            92 Oct 08 06:17 x.log   I used the below command  find . -type f -newer 2013-10-08 ! -newer 2013-10-08   which gave an error  find: 0652-015 Cannot access file 2013-10-07


I am having troubles getting a cronjob on ubuntu 16.04 digital ocean to work.   I programmed a python spider, which i want to run every 5 minutes. In order to run this spider I made a script runmyspider.sh (chmod +x) with the command:  scrapy runspider aspider.py   Now I want to call this script via Cron.   */5 * * * * sh /scripts/runmyspider.sh 2>&1 /scripts/spider.log   However, the spider never runs (I can see that no changes in the database have been made, if I execute the file manually the changes happen)  What am I doing wrong here? I have set up a cron multiple times before, but this time I seem to get an error into it...  Thanks for all your advice!


Proof that the function $f$ is not injective.

Let $f:U\subset\mathbb{R}^m\rightarrow\mathbb{R}^n$ be a function of class $C^1$ with $m> n$. Prove that $f$ is not an injection function.  I do not know how to solve this problem. Could someone help me with the solution to this problem?


ALL, I have a Windows 8.1 laptop that I recently put some updates on. Unfortunately it looks like I got some stupid "Wish Application" pinned to my task bar (the icon looks like an Alladin lamp). I tied to uninstall it from the Control Panel, but it doesn't list it. Does anybody know how to get rid of it? TIA!


calculate the series $\sum_{n=0}^\infty n(n+1)z^n $

I have found the convergence domain, which is $$|z|<1$$ now for this domain I am trying to calculate the series $$\sum_{n=0}^\infty n(n+1)z^n $$


So this is something I just found out about that I find odd:   Opportunity attacks—trigger off of movement that uses the creatures movement (action, move action, bonus action, reaction.)  Sentinel—Whenever a creature within 5 ft of you makes an attack at a creature other than you.   Booming blade—If the target willingly moves.   Mental Prison spell—if it moves, attacks through it, or reaches any part of body out of it.   So the “willingly” is different than other rulings for how effects related to movement works. However what exactly fits willing?   Cause fear—nope magic is having them move. Dissonant whispers—same thing. They have to immediately move.   So the creature has to want to move completely of its own accord.   Crown of Madness—Humanoid creature you choose must make a wisdom saving throw. On a fail it is charmed by you. (Next is flavor text so skipping.) While charmed in this way the target must make an attack on a creature other than itself that you mentally choose on each of its turns before moving.  It can act normally if you choose no creature or if none are within reach.   Crown of madness isn't making them move but doesnt specifically say willing.  And if the ruling for willing is movement not caused by magic what about magic causing situations where you take damage if you don't move. Would a creature shimmering with evocation energy be spared because he moved out of the magical blender that is cloud of daggers? If no, then what is the go-to rule for willing movement that I should be using?  In short, what movement counts as willing, and where can it be found? Is moving out of obvious danger caused by magic, willing? Is moving away from an ally so you don't hit them, willing?   If there isn't any actual ruling on willing, that's fine; I'll go back to running it with my interpretation, so that it has same wording as AOO. If there is an actual 5e term or explanation for willing (that isn't Sage Advice), please let me know. I just don't see why it was necessary to put a term in the spell that isn't used anywhere else. I understand it could have been overlooked since it was in a splatbook or has just been ignored since most people probably assume that there is "Forced " and "Willing" movement, with the willing being defined as: any movement from an action, move action, bonus action, or reaction. In same way AOO work.


Deleting a comment (mine) shouldn't count as a comment vote

I had an old question that I revisited in order to link it in a new answer. I noticed that in the comments Steven A Lowe had a funny comment that I -- at the time -- had responded to with "why can't I upvote comments?"  Well, of course, now I can.  So, I voted Steven's comment up then went to delete mine. I got the warning box that I can only submit comment votes once every 5 seconds. This seems like a bug to me. Deleting is not the same as voting.


Fantasy story with a young female protagonist and an ageless wizard

I am searching for a series of young adult books I read approximately 10 years ago (2010). They were from a library so I assume they can't have come out before 1990.  There are two protagonists: a young girl of around 13-16 and a wizard who is much older (50+).  As a consequence of a ritual performed at the beginning of the first book, the wizard looks permanently in his mid-twenties despite being much older. I think he binds his soul to a book, he may also be missing an arm.  At some point, the girl uses the book to enact another ritual which ages her about 10 years. She then attempts to romantically pursue the wizard. The ritual makes use of a lot of blood.  There is a villain who wears the pelt of a wolf and is able to shapeshift into a wolf. In one of the later books, he wears the skin of a person who can shapeshift into anything and gains this power.


Proving the Cantor Pairing Function Bijective

How would you prove the  bijective? I only know how to prove a bijection by showing (1) If $f(x) = f(y)$, then $x=y$ and (2) There exists an $x$ such that $f(x) = y$  How would you show that for a function like the Cantor pairing function?


How to outline a 3D object with a cartoon style stroke?

How could I draw (stroke) the outline of a 3D object in a cartoon style with GLKit?  I'm referring to something like this:     However we can start with a simple line around the object and then try to improve the stroke with a shader.  I'm drawing the object with this code:  glBindVertexArrayOES(_vertexArray); glDrawElements(GL_TRIANGLES, sizeof(Indices)/sizeof(Indices[0]), GL_UNSIGNED_BYTE, 0)   As I'm not very familial with GLKit: all the solutions I've found make use of OpenGL APIs not supported by OpenGL ES.


How many maps $\phi:\Bbb{N}\to\Bbb{N}$ are there with $\phi(ab) = \phi(a)+\phi(b)$?

I am stuck on the following problem when I was trying to solve an entrance exam paper:  How many maps $\phi \colon \Bbb N \cup \{0\} \to \Bbb N \cup \{0\}$ are there with the property that $\phi(ab)=\phi(a)+\phi(b)$ for all $a,b \in \Bbb N \cup \{0\}$ ?  The options are as follows :   none  finitely many  countably many  uncountably many    Option 1 is not possible as if we take $a=1,b=0$ then we get $\phi(1)=0$ which is possible. But, I am not sure about the other options and could not decide which one holds good. Can someone explain?


Generalised Chi-square distribution for variables with differing means and variances

Is there a generalised $\chi^2$ distribution for the case where the Normal random variables $X_i$ all have differing means and variances? Wikipedia (and most sources I find) give the , but states that the Normal random variables must have unit variance. There is  that gives a definition allowing for non-unit variances, but that definition has no further citations and doesn't seem to be backed up by anything I can find on the internet. For my purposes, I cannot normalise the random variables to have unit variance.


I am blocking on this question :  Is every instance of Y able to call the method aMethod() of every other instance of Y. The answer I found is NO.       package a;      class X{      protected void aMethod()     { }      }       package b;  class Y extends X     { }   Can you explain to me why? thanks.


$f\left(x,y\right)=\left(\frac{x}{x^{2}+y^{2}  } , \frac{y}{x^{2}+y^{2}  } \right)  $  How do I find inverse function? I have trouble here, because there are 2 variables and I am not sure how to do it?


I need my enum to return a formatted string to the view, for example:   public enum status {     NotStarted,    InProgress, }    return: Not Started and In Progress. How I do it? Thanks (language C#)


The site software is %-encoding asterisks in URLs, and it shouldn't(?)

Consider the following link:  https://doc-0g-bc-docs.googleusercontent.com/docs/securesc/ha0ro937gcuc7l7deffksulhg5h7mbp1/9la5prt2u93men2ft6831kkki73u94n0/1403496000000/02058467015715614041/*/0ByTrbPQHgxJddnBTSlUxZVNBOG8?h=16653014193614665626   If I try to include it as a link in this post using the "displaced URL" syntax (), the href of the resulting <a> (in the output, not the markdown) gets converted to:  https://doc-0g-bc-docs.googleusercontent.com/docs/securesc/ha0ro937gcuc7l7deffksulhg5h7mbp1/9la5prt2u93men2ft6831kkki73u94n0/1403496000000/02058467015715614041/%2a/0ByTrbPQHgxJddnBTSlUxZVNBOG8?h=16653014193614665626   If you scroll to the right, you will see that the difference is that * in the URL has been %-encoded to %2a. But here is the problem: the version of the URL with the * goes to the right place (here is a link from a shortener:  - you should get a PDF of the Ramayana), while the link above, which has %2a, does not.   I'm not sure whether this is a bug in SE or in Google, but even if it is a bug at Google, it would probably be a good idea for SE to have a workaround for it.  Note also: If I try to use a literal <a> tag in my post to include the link, it fails to render: (). The same URL with the * removed links just fine using a literal <a> tag () (albeit there's nothing at that URL), so this is probably a symptom of the same underlying problem.


what does this symbol '()' do after closing '{}'in javascript

I'm really sorry with the title, and im sorry if im asking this noob questions here, because i don't know what the keyword for this in google.  Ok, first i'm new to javascript and still learning this programming language. so i've seen this alot, but i don't know what it's mean  var myapp = function(){    var a = 'a';   var b = function(){     //some code goes here   }    return {      init: function(){     b();     //some code goes here      }    }  }() <-- what is it?;   So i've been wondering what this symbol '()' do at the end. and why many people writing a function inside a variable?


Why does the terminal not hold my root password for sudo?

I stopped using Ubuntu for a while (since 12.10) and recently came back to it. From what I remember, it used to only ask for the root password once for a terminal session (for sudo commands). Now it asks me everytime I want to sudo something. Is there a way to fix this? or is this intentional?  The same thing happens with git. I have enter my credentials everytime I want to commit. I know my friends on on mac don't need to do this. Are the two issues related?  Any help would be appreciated. Thanks in advance!


I know this is a very basic question in C, so I apologize beforehand if this is naive: I'm just learning the basics a few days in.  int main() {      // initialize the variables     int num_whitespaces, num_other;     int num_digits[10];     printf("%lu", sizeof(num_digits));  }   This prints 40, which seems odd to me. Why wouldn't this print 10, which would be the length of the array in javascript or so.


Prove that for every p - prime, $p>3$ the numerator of sum of $p-1$ summands of harmonic series is divisible by $p$ square.  I've written 1 A4 but so far without victory. This can't require advanced tools, as it is an exercise after chapter with only Euler's Theorem, Wilson's Theorem and CRT.  I've tried with Wilson's by multiplying everything by $(p-1)!$ and then write $(p-1)!=(p-1)*(p-2)!$ and later calculus -  but it does not work so far.  Thanks in advance for help.


Even when I start a brand new file in Blender, I only get four video output file options: AVI raw, AVI JPEG, Frame Server, FFMpeg Video.  I am running version 2.78.5 (I'm using the beta so that I can use denoising.  How can I get access to all the other video outputs other people have? Like this:


Pipe stdout of two programs to each other

I have two programs, one of them prints something first, they need to communicate with each other with their standard IO.  Is there a way in Bash to pipe stdout of two programs to each other? I know I could do this in C with forks and dups, but is there a way with pure Bash?


How can I fix my regex to not match too much with a greedy quantifier?

I have the following line:  "14:48 say;0ed673079715c343281355c2a1fde843;2;laka;hello ;)"   I parse this by using a simple regexp:  if($line =~ /(\d+:\d+)\ssay;(.*);(.*);(.*);(.*)/) {     my($ts, $hash, $pid, $handle, $quote) = ($1, $2, $3, $4, $5); }   But the ; at the end messes things up and I don't know why. Shouldn't the greedy operator handle "everything"?


Modular arithmetic - re-arranging equation to get outcome

Is it possible for me to show  $a=7\beta-7\alpha,\ b=3\alpha-2\beta$  If I know that   $\alpha=4a+b,\ \beta=19a+b$  in $mod\ 26$  Any help would be much appreciated, I'm new to modular arithmetic, so still figuring things out.


How can I get iOS reminders to appear on google calendar?

I like setting reminders using Siri (e.g. "remind me to buy milk tomorrow at 8pm").  Siri understands what I am trying to say and pretty smoothly adds the reminder. I would like this reminder to appear on my google calendar (i.e. some event starting at 8pm ending 15 minutes or 30 minutes later, with my message on the reminder).  How can I do this? I set a ton of reminders using Siri, and this would be a great way for me to get a birds eye view (and maybe a leg up) on all the stuff I have to do.  Thanks in advance!


given problem is,  If $\Sigma\vdash\varphi$ iff $\Sigma\vdash\psi$, then $\Sigma\vdash\varphi\leftrightarrow\psi$.  I can prove this using sound&completeness theorem but I don't know how to do without those theorems.  without them, I proved when $\Sigma\vdash\varphi$ is true, but I couldn't prove when $\Sigma\nvdash\varphi$. without the theorems, I don't know how $\nvdash$  part contributes to prove the problem.  p.s. only member of given set, tautology, and Modus Ponens are allowed for deduction.


eigen value problem of the following matrix

$$A=\begin{bmatrix} 1 & -2 & 3 & -2 \\ 1 & 1 & 0 & 3 \\ -1 & 1 & 1 & -1 \\ 0 & -3 & 1 & 1 \\ \end{bmatrix}$$  4.9 Pick out the smallest disc in the complex plane containing all the eigenvalues of $A$ from amongst the following:   $|z-1| \leq 7$; $|z-1| \leq 6$; $|z-1| \leq 4$.   How to solve the problem 4.9?


How to correct Dovecot user login to use full domain email in this format "myuser@mydomain.com"

I have configured dovecot and postfix...Email server works fine.. (Webmail and outlook both works..)  I have created users using unix command ..  usreadd -s /sbin/nologin myuser   But i have a concern, if i want to login to webmail or outlook I have to use myuser instead of myuser@mydomain.com.  For the time being im using, only user name as below..    If i use myuser@mydomain.com it says its invalid user both webmail and outlook..  I tried googling .. no luck.. yet.. kindly some one please shed a light..   10-master.conf is   #default_process_limit = 100 #default_client_limit = 1000  # Default VSZ (virtual memory size) limit for service processes. This is mainly # intended to catch and kill processes that leak memory before they eat up # everything. #default_vsz_limit = 256M  # Login user is internally used by login processes. This is the most untrusted # user in Dovecot system. It shouldn't have access to anything at all. #default_login_user = dovenull  # Internal user is used by unprivileged processes. It should be separate from # login user, so that login processes can't disturb other processes. #default_internal_user = dovecot  service imap-login {   inet_listener imap {     #port = 143   }   inet_listener imaps {     #port = 993     #ssl = yes   }    # Number of connections to handle before starting a new process. Typically   # the only useful values are 0 (unlimited) or 1. 1 is more secure, but 0   # is faster. <doc/wiki/LoginProcess.txt>   #service_count = 1    # Number of processes to always keep waiting for more connections.   #process_min_avail = 0    # If you set service_count=0, you probably need to grow this.   #vsz_limit = 64M }  service pop3-login {   inet_listener pop3 {     #port = 110   }   inet_listener pop3s {     #port = 995     #ssl = yes   } }  service lmtp {   unix_listener lmtp {    # mode = 0666   }    # Create inet listener only if you can't use the above UNIX socket   #inet_listener lmtp {     # Avoid making LMTP visible for the entire internet     #address =     #port =    #} }  service imap {   # Most of the memory goes to mmap()ing files. You may need to increase this   # limit if you have huge mailboxes.   #vsz_limit = 256M    # Max. number of IMAP processes (connections)   #process_limit = 1024 }  service pop3 {   # Max. number of POP3 processes (connections)   #process_limit = 1024 }  service auth {   # auth_socket_path points to this userdb socket by default. It's typically   # used by dovecot-lda, doveadm, possibly imap process, etc. Its default   # permissions make it readable only by root, but you may need to relax these   # permissions. Users that have access to this socket are able to get a list   # of all usernames and get results of everyone's userdb lookups.  # unix_listener auth-userdb {  #   mode = 0600  #   user = postfix  #   group = postfix  # }     #Postfix smtp-auth   unix_listener /var/spool/postfix/private/auth {   mode = 0666   user = postfix   group = postfix   }    # Auth process is run as this user.   #user = $default_internal_user }  service auth-worker {   # Auth worker process is run as root by default, so that it can access   # /etc/shadow. If this isn't necessary, the user should be changed to   # $default_internal_user.   #user = root }  service dict {   # If dict proxy is used, mail processes should have access to its socket.   # For example: mode=0660, group=vmail and global mail_access_groups=vmail   unix_listener dict {     #mode = 0600     #user =      #group =    } }   Results for  dovecot -n  # 2.0.9: /etc/dovecot/dovecot.conf # OS: Linux 2.6.32-042stab093.4 x86_64 CentOS release 6.6 (Final) auth_mechanisms = login plain disable_plaintext_auth = no mail_location = maildir:~/Maildir mbox_write_locks = fcntl passdb {   driver = pam } service auth {   unix_listener /var/spool/postfix/private/auth {     group = postfix     mode = 0666     user = postfix   } } ssl_cert = </etc/pki/tls/certs/mycert.crt ssl_key = </etc/pki/tls/private/mycert.key userdb {   driver = passwd }


Why "\s" format of PS1 variable displays "-" prefix?

From the manual of PS1: `\s    The name of the shell, the basename of $0 (the portion following the final slash)`  From the terminal output: export PS1="\s"     -bash  Why the dash (-) is there?


how to use RFE(Recursive feature elimination) on categorical (one-hot encoded variables)

for categorical variables that are one-hot encoded, each level is now a feature' in my data. for example: "Married" is now "Married_Y" and "Married_N", so there is a chance that only "Married_Y" will be chosen in RFE. I imagine this is not a valid way for feature selection (if i'm wrong, please let me know how to interpret this type of situation). In this case, how do I go about doing RFE? My goal is to run RFE on a logistic regression model to understand which variables i should consider keeping or not.


If $P$ is false, and $Q$ is true, then why does $P \implies Q$?

I have often seen truth tables similar to this one:  The first two rows, where $P$ is true, make sense to me. However, why does $P$ being true and $Q$ being false mean that $P \implies Q$? To make the question clearer to myself, I came up with the following example: let $P$ be whether or not it is raining. Let Q be whether or not I am wearing a coat. Then, there are $4$ possibilities:  It is raining; I am wearing a coat.  It is raining; I am not wearing a coat.  It is not raining; I am wearing a coat.  It is not raining; I am not wearing a coat.   $P \implies Q$ is the same as saying if it is raining, then I will wear a coat. This statement says nothing about what happens when it is not raining. Therefore, why do we say not raining $\implies$ coat?


Relationship between physical and information entropy

This question is inspired by the following example given in Barnett's book on quantum information:        (PDF , starting at the bottom of page 5)  I am not a physicist, but I'll accept that the calculation of the increase in physical entropy associated with this procedure is correct. My confusion is about how the second law of thermodynamics can be saved by claiming that the process of measuring the position of the molecule produces an entropy of at least $k_B\ln2$.  My question is: Why can we just assume that "entropy" of information is comparable with physical entropy? The best explanation that I've been able to find is that they're defined in similar ways and satisfy the same basic properties. This seems no different from saying "decibels and earthquake intensity are both measured logarithmically and are therefore comparable", which of course makes no sense.  As I said above, my only physics background is a first-year course, so I'd appreciate if answers could try to be accessible to someone who hasn't done thermodynamics...


Allow users with lots of rep (3500?) to promote “comments” to “answers"

I’ve spent the last week diving into StackOverflow, and one of the biggest annoyances I have is questions that remain open and “unanswered” forever because someone suggested the answer as a comment and just left it there.  This doesn’t help anyone. The person who left the comment doesn’t get credit and the people looking for questions to answer have a ton of noise in their feeds.  There needs to be a way for third-parties to change “comments” into “answers,” at the very least.  Take this question, .  If Greg turns out to be right, it’s mostly likely going to stay open forever. And Greg’s not going to get credit even if some friendly editor does come along and rephrase his comments and post them to the community wiki.  I submit to you that any system that requires editors to rewrite other people’s answers entirely is not a good system. Also, I think it’s a fair bet that a lot of original posters aren’t going to go back and check for more answers to their questions once they’ve solved their problem, so even if an editor DOES make a community wiki answer, it’s unlikely it’ll ever be marked as being the “one true answer.”  Honestly, if the current system were working I don’t think I’d see questions going back years and years that have “no” answers but really are answered in the comments (and the original poster thanks them in the comments, and that’s that).


Prove $G$ is cyclic if for every $n\in \Bbb{N}$, there are at most $n$ solutions to the equation $x^n=e$.

Let $G$ be a finite group. Prove G is cyclic if  for every $n\in \Bbb{N}$, there are at most $n$ solutions to the equation $x^n=e$.    I am stuck with this :( Would appreciate your help.


How come the Meta chat rooms are separate?

Like completely cut-off from the rest of the chat rooms (on the Stack Exchange network).  The favorites are separate, and the  current rooms are separate, (even the search) - all of it; it's all really annoying. (I just don't ever visit those particular rooms.)  Sorry if this came off as a rant, not so at all. I am just wondering why it's like this.    Here are some examples:  • Starting with the domain: https://chat.meta.stackexchange.com/  The Favorites:    Within a room, I don't have access to my other active rooms:    And vice-versa.  Even the logo:      In all my rooms, I have access to other rooms I'm currently in, I can see all my favorites (no matter the site - besides Meta.SE), and I can search for any room as well. (besides Meta.SE)  Is this done on purpose? If so, what are the cons of having it the other way, etc.?


My sentence is as follows:     Carol Ohmann discusses in her article Daisy Miller: A Study of Change in Intentions how the main heroine of Henry James' novella brings rise to arguments.     Do I have to set the title of the article off in commas or leave it as it is written?


Calculating $\prod (\omega^j - \omega^k)$ where $\omega^n=1$.

Let $1, \omega, \dots, \omega^{n-1}$ be the roots of the equation $z^n-1=0$, so that the roots form a regular $n$-gon in the complex plane. I would like to calculate $$ \prod_{j \ne k} (\omega^j - \omega^k)$$  where the product runs over all $j \ne k$ with $0 \le j,k < n$.    My attempt so far  Noting that if $k-j = d$ then $\omega^j - \omega^k = \omega^j(1-\omega^d)$, I can re-write the product as $$ \prod_{d=1}^{\lfloor n/2 \rfloor} \omega^{n(n-1)/2}(1-\omega^d)^n$$  I thought this would be useful but it hasn't led me anywhere.  Alternatively I could exploit the symmetry $\overline{1-\omega^d} = 1-\omega^{n-d}$ somehow, so that the terms in the product are of the form $|1-\omega^d|^2$. I tried this and ended up with a product which looked like $$\prod_{j=0}^{n-1} |1 - \omega^j|^n $$  (with awkward multiplicative powers of $-1$ left out). This appears to be useful, but calculating it explicitly is proving harder than I'd have thought.  The answer I'm expecting to find is something like $n^n$.    My motivation for this comes from Galois theory. I'm trying to calculate the discriminant of the polynomial $X^n+pX+q$. I know that it must be of the form $ap^n+bq^{n-1}$ for some $a,b \in \mathbb{Z}$, and putting $p=0,q=-1$, the polynomial becomes $X^n-1$. This has roots $1, \omega, \dots, \omega^{n-1}$, so that $(-1)^{n-1}b$ is (a multiple of) the product you see above. An expression for $a$ can be found similarly by setting $p=-1,q=0$.


How can you upgrade Nookling Junction into T&T Mart in Animal Crossing: New Leaf? I don't know how to upgrade Nookling Junction.


Why did they say Kovacs is the last Envoy in the books?

In the first book, they make it clear he is the last Envoy. Everyone thinks they're all gone.      By the third book, they make it very clear the Protectorate can send Envoys if they want.    Did I miss something?


Preparing HTML Form Input for SQL Database using PHP

I'm currently testing a html form which sends the data through php to the sql database. The problem I'm facing is special characters break the form and don't update the database. I haven't tested all the special characters but mainly ` and ' are the culprits. I've tried mysql_escape_string, preg_replace and add_slashes with no success. What am I missing?  $description = preg_replace('/[^A-Za-z0-9\ %&$=+*?()!.-]/', ' ', $_POST['description']); $description = preg_replace("/[\n\r]/"," ",$description);  // Items Insert foreach ($item as $index=>$value) { $sqlItems .= "     INSERT INTO quote_items (quote_id, item, description, amount, gst)     VALUES ('$last_id', '$item[$index]', '$description[$index]', '$amount[$index]', '$gst[$index]'); "; }   Thanks in advance!


Please add a tag search functionality to Careers

First, if this is the wrong place then I have to say that someone needs to fix the links in the footer of Careers site (this is how I ended here).  Anyway, I was looking for "C" jobs, and found lots of unrelated jobs instead, and lots I mean LOTS. Thus the site is impossible to use.  I want a C job, not C++, Obj-C, or even things that are not even related at all (I got returns for perl, python, mysql, and lots of other random stuff).  So, Careers site should have a way to search only what you want, maybe use SO search system, where if you type [c] it will search ONLY, and ONLY REALLY ONLY the tag C (instead of random words in the description that contains the character C).


To have nice tabbed text next to equations?

I want     I have at the moment    by  \documentclass{article} \usepackage{amsmath} \begin{document} \begin{subequations}   \begin{equation}     \omega_c = \sqrt{\omega_{0}^{2} - \mu^{2}}, \mu < \omega_{0}, \text{ Underdamped}   \end{equation}   \begin{equation}     \omega_c = \sqrt{\mu^{2} - \omega_{0}^{2}}, \mu > \omega_{0}, \text{ Overdamped}   \end{equation}   \begin{equation}     \omega_c = 0, \mu > 0, \text{ Critically damped.}   \end{equation} \end{subequations} \end{document}   which I do not like.  How can you have nicely tabbed text next to equations?


Does the Universal Translator also translate controls and control panels?

In the series 7 episode of Star Trek: Voyager, "Nightingale", Ensign Kim repairs and takes control of a Kraylor ship.   I'm curious at the ease at which Kim fixes the warp matrix using the control panel. Does the UT also translate the control panels and displays? The  suggests that it does, but doesn't out and out say it.  Is there a canonical statement of the UT's ability to also handle visual languages, not just aural?


Armadillo Cloak contains a triggered event that in combat resolution resolves?

When 's ability is triggered due to combat it is placed on the stack.  My assumption is that the stack does not resolve till the second main phase and only after all players have passed.  Is this correct?


TeXLive with TextMate -- Documents have suddenly stopped compiling

I just tried to compile a document and got this message:  This command requires ‘kpsewhich’ which wasn’t found on your system.  The following locations were searched:  • /usr/bin  • /bin  • /usr/sbin  • /sbin  • ~/Library/Application Support/TextMate/Managed/Bundles/Bundle Support.tmbundle/Support/shared/bin  • /usr/local/bin  If ‘kpsewhich’ is installed elsewhere then you need to set PATH in Preferences → Variables to include the folder in which it can be found.   I've been away and haven't really used TeX in a while; I think there were upgrades to TextMate and possibly TeXLive before I left town, but I don't remember.  Following the TexLive documentation, I created a new texmf.cnf file, placed it in /usr/local/texlive/texmf-local/web2c, and tried to run sudo -H mktexlsr, only to be told command not found. Now I'm stumped. How can that command not be found? What is the remedy?


I was using a ROUNDUP functions and find a very strange answers and later i found out that 1-1.09 = -0.0900000000000001 according to excel. i am not a mathematician but i think than correct answer 1 - 1.09 must be -0.09. i cant figure it out why the answer is -0.0900000000000001. is this a bug or i have missed something?  P.S. I am using Excel2016 16.0.4417.10000 64-bit, on Windows 10


Which of the following sentences is or are correct:  Doing sports helps keeping fit. Doing sports helps keep fit. Doing sports helps to keep fit.  Thank you.


Wrong pixel sums within buffers in Esri ArcGIS 10.0

I have a raster of Zambia, 100m² resolution (about 650mb). Buffers (single) at 1,2,3,4,5,10,15,20,25,30,50 km.   I'm running "zonal statistics as table" in the model builder for all buffers (actually, the buffers are run in the model builder as well). How do I know the sums are wrong? Some of the larger buffers have smaller pixel sums than the smaller buffers. I've cut down the dataset so that there are about 150 points to buffer. I've run the problematic points/buffers individually and they returned identical results. This might be related or suggest where the problem is coming from: When I tried to clip the buffers to the country outline (most of the problematic buffers are around the edges or where the points are in close proximity to each other). I get a Invalid Topology [Topoengine error.] message. How can I resolve this?


Can we find in history command the dates & timing of the command execution

This command does not give time & date when command was executed. Is this possible to check date & time  with history command or other command.  $ history     1  cd /strswork/strsapp/applications     2  ll     3  cd UM1     4  ll     5  cd DEV/oldlogs     6  ls -ltr     7  cd ..     8  ls -ltr     9  tail -10 log.txt    10  more log.txt


Windows 8  I really want to replace ubuntu with windows 8. I cant figure out how :O Can someone please help me?   And yes, i have bought windows 8. I have the ios file, but I also need help to create a bootable Usb stick.


Remove migration notices from destination post

As part of the roll-out of new , questions that were migrated now show a notice at the top indicating that they were migrated.    I ran across a question today that is seven years old.  After seven years, there is no need to highlight prominently that the question originated on a different site.  This is the very first thing we are showing people who visit that page -- yet it's one of the least important things about the question.  Suggestion: The notice indicating that a question was migrated from somewhere else should be removed after a fixed period of time (say, 30 days).  It's unfortunate that this notice is shown at the top of questions.  It's not what we should lead off with.  It's not relevant any longer (who cares?  it's irrelevant; it might have been relevant when it was first migrated, but seven years now).  It's distracting.  It also potentially leaves the impression that there is something wrong with the question or some reason why it needs to be marked, marking the question in perpetuity.  A similar request was made two years ago ().  However, that was before the new post notices.  Back then, the "migrated" notice was shown at the bottom, underneath the question -- so the first thing that people saw was the question, and the "migrated" notice was less problematic.  Now, that notice has been moved to the top, above the body of the question, and it is more problematic.  Note: I'm talking about the post notice on the destination site, not on the source site.


Why is the electric field zero inside a hollow conducting sphere?

If you have a conducting hollow sphere with a uniform charge on its surface, then will the electric field at every point inside the shell be 0. The reason the electric field is 0 at the center is clear from the symmetry of the sphere, but for a point at a certain distance from the center, shouldn't a net electric field exist?  I saw a similar question on the site but it was vaguely explained.


Cplusplus.com - is it bad to use links from it to answer?

I was reading this question , and one of the answers provided a link to . That answer got a down vote with a  saying " -1 for link to cplusplus.com."   the comment provided a  but it is expired.  Is there something wrong with using that website as a reference for answers ?


Anybody Implemented pagination using SLDS

I have to implement pagination by using SLDS. I didn't able find any example of pagination. Please provide example?


Suppose $a, b$ and $n$ are positive integers. Prove that $a^n$ divides $b^n$ if and only if $a$ divides $b$.

I think prime factorization is needed for this question:   Suppose $a$, $b$ and $n$ are positive integers. Prove that $a^n$ divides $b^n$ if and only if a divides $b$.


Sum vector data correlating with a second vector layer

There are a lot of questions very similar to mine, but I couldn't find one that accurately described what I want to do.  I am working in QGIS.  I have one vector layer which, among other attributes, has a production volume for oil wells.   I have a second layer which represents townships.  Some townships have five wells, some have none etc., all with different levels of production.  I want to create a new layer which displays all the townships with a summation of the total production volume within the township.  Can anyone think of an efficient way to do this? EDIT: I would also like to be able to the sum of the production volumes to the township layer.  Thanks!


Instantiating multiple instances of a class from within

Can someone explain how the below code works without any exceptions. I am thinking when new instance is created for SUNDAY it creates a new instance for MONDAY (inside SUNDAY) too and then SUNDAY again (inside MONDAY) and so on... Something like recursive as they both are part of the class Week. But my understanding is wrong because the below code is working fine.  public class Week {     public static final Week SUNDAY = new Week("SUNDAY",0);     public static final Week MONDAY = new Week("MONDAY",1);      private String name;     private int val;      private Week(String name, int val) {         this.name = name;         this.val = val;     }      public int getIndex() {         return this.val;     }      @Override     public String toString() {         return this.name;     } }   I got this doubt when I was reading about java enums.


I had previously asked  for 3D but now I changed my strategy and would like to do the intersection in 2D.  The Rectangle is axis aligned and will always be in a fixed position, and has a constant shape and size, basically I want to clip the red areas of the triangles that extend outside the bounds of the rectangle.  The triangles could be in any position, shape or size, I my code I have a loop where I check the triangles one by one, however I am still clueless about the math.  I have identified 5 cases of triangle rectangle intersection as shown here.  How do I find the intersection points of the triangle and the rectangle?


Unity will not load on boot, or via command line. Enabling in CCSM does not stick

I really don't know what to do.  When I enable Unity in CCSM, it doesn't load.  When I close the app, the settings don't stick.  Updating and upgrading didn't help.  Running the unity command in the command line doesn't help.  ANy ideas?


Cloning Ubuntu and use it in dual boot with windows

I have a Dell laptop that runs Windows 10. I also have an empty partition on this laptop's HDD that I want to install Ubuntu there and use it as a dual boot machine. In addition I have Lenovo laptop with Ubuntu on it. I want to clone my Lenovo machine and install this image on the Dell free partition. I found the clonezilla app to clone my Lenovo machine but also read that I need the target disk to be exactly (or more) the size of the original disk. Does anyone knows if it possible to clone my Lenovo machine and install it on the free partition on my Dell's HDD?


Is there a specific accounting-oriented hypernym for the directions of cash flow, i.e. debit and credit?


How Secure Is PHP PDO To SQL Injections?

Here's the code I'm using in PHP. I was wondering if it's SQL Injection Proof or I need to do something more to make it more secure to SQL Injections: $server = "localhost"; $user = "username"; $pass = "password";  try{ $conn = new PDO("mysql:host=$server;dbname=mydatabase", $user, $pass); $conn->setAttribute(PDO::ATTR_EMULATE_PREPARES,false); $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch(PDOException $error){ echo 'Something Went Wrong' . $error->getMessage(); }  try{ $items = $conn->prepare("SELECT * FROM menu_items"); $items->execute(); if($items->rowCount() == 0){ echo 'No Data In Records'; } echo json_encode($items->fetchAll(PDO::FETCH_ASSOC)); } catch(PDOException $error){ $error->getMessage(); }


When running the function: function updateCells() {   var ss = SpreadsheetApp.getActiveSpreadsheet();   var spreadsheetSummary = ss.getSheetByName('Summary');   const range = spreadsheetSummary.getDataRange()   const values = range.getDisplayValues()   const transposeCheck = values[0].map((_, iCol) => values.map(row => row[iCol]).some(cell => cell))   var countBoolean = transposeCheck.filter(Boolean).length + 1   var spreadsheetCommunityGroups = ss.getSheetByName('Community Groups');   var cellValueCommunityGroups = spreadsheetCommunityGroups.getRange('A12').getValue();   var summaryCommunityGroups = OFFSET('A2', 0, countBoolean);    sreadsheetSummary.getRange(summaryCommunityGroups).setValue(cellValueCommunityGroups); }  I receive the error ReferenceError: OFFSET is not defined. What I want is to place the value of A12 from the Community Groups sheet into the cell "1 column to the right of the last cell in row 2" of the Summary sheet. I count the number of occupied columns and 1 and save this as countBoolean, and this is what I am using to offset the columns.


What is a counterexample for If $x\in\overline{A},$ $x$ is not necessarily a limit of a sequence in $A$?

Let $(X,\tau)$ be a topological space, $\emptyset\neq A\subseteq X$ and $(x_n)$ be a sequence in $A$. I could easily show that any limit of $(x_n)$ belongs to $\overline{A}$. My note says that if $x\in\overline{A},$ $x$ is not necessarily a limit of a sequence in $A$. But I cannot find a counterexample. Now in my attempt to find a counterexample, which I failed, I could conjecture that if the topological space is metrizable then, if $x\in\overline{A}$ then $x$ is a limit of a sequence in $A$. Is my conjecture true? And how would you find a counterexample to the original problem? Please help. Thanks.


I want to insert Names of authors in the toc (above the chapter title) :   but the suggested methode doesn't work in the scrreprt type of document.  \documentclass[12pt,a4paper,oneside,ngerman]{scrreprt} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{lmodern} \begin{document} \tableofcontents  \chapter{Blabla 1} sdadasdas  \section{Blabla 1.1} fd \subsection{Blabla 1.1.1} das \end{document}   Thanks in advance!


Currently, flagging or voting to close as a duplicate on the iOS app gives you a simple text input to paste a question URL or ID. No duplicate suggestions, no search,   I know there are limitations on what can be implemented because of what is accessible through the API and there can be difficulties in implementing the UI for smaller devices. But, as I discovered yesterday, . So, can we implement:   Duplicate suggestions, as the Android app already has. A search UI similar to the full-site duplicate dialog.    The suggestions already exist on the Android app so there shouldn't be any trouble porting that to iOS, and there is already search functionality elsewhere in the app so that shouldn't be a problem either. There is an existing feature-request:  which would be far exceeded by this.


for which odd number n does 503 divide $n^2+1$

The question is already mentioned in the title: For which odd number n does 503 divide $n^2+1$  $503\cdot q=n^2+1$


Cumulative distribution function of continuous random variables

Marginal density functions: $f_{V}(v)=f_{W}(w)=\frac{1}{60}$  Joint density function: $f_{V,W}(v,w)=\frac{1}{3600}$, for $0\leq x\leq60$ and $0\leq y\leq60$  I need to find the cumulative density function of $T = W - V$  I'm thinking it's something along the lines of this:  $F_{t}(t)=\left\{\begin{matrix} 0 & w-v<0\\  \frac{t}{60} & 0 \leq w-v \leq 60\\  1 & w-v>60 \end{matrix}\right.$  Any help appreciated.  Thanks!


How to have pidgin chat windows open up on all workspaces?

I use pidgin as my chat client on ubuntu lucid. Whenever I have a chat window open, I like to mark it as "Always on visible workspace" as it's just more convenient.  Is there a way that I can force chat windows to already be marked as that when they open up? So, if someone started a conversation with me on gtalk (for instance) the window would automatically be on all workspaces, and I wouldn't have to mark it manually.


I am attempting to find solutions to $x^y = y^x$. I have been trying to find solutions to this equation for quite some time now, and using all the math (and common sense) I know, I arrived at one possible non trivial solution, $x = 4, \;y =2.$ Are there other solutions to this equation and if there are how do I find them?


Intel Corporation's board of directors has declared a quarterly dividend of 22.5 cents per share (90 cents per share on an annual basis) on the company's common stock. The dividend will be payable on Sept. 1, 2014, to stockholders of record on Aug. 7, 2014.   Does the above mean I can sell stock on Aug 8th and still get a dividend or do I have to wait until Sep 2nd?


Can the universe have a definite energy density?

We only can speak about the energy density in a container if its energy content is independent from its dimension -so could, in principle, have any value at all. If in Einstein’s statement “People before me believed that if all the matter in the universe were removed, only space and time would exist. My theory proves that space and time would disappear along with matter” we may replace ‘matter’ with ‘energy,’ then the energy content of the universe is not independent from its volume. Doesn’t this mean that we cannot then speak about the energy density of the universe as a whole?


Javascript Regex as a string not working

I am trying to understand why writing regex as a string is not working but using it without string does work.  this is my example:  var patt = new RegExp("/test_.*/gi"); var res = patt.test("test_4"); console.log(res);   will return false  but this:  var patt = /test_.*/gi; var res = patt.test("test_4"); console.log(res);   will return true  what is the difference


I am new started machine learning program. I find it difficult to understand gradient descent algorithm. I am going through machine learning from coursera by Andrew Ng.All of his lecturer in second week course is around gradient descent algorithm. Since I don't understand this formula , I am unable to move further on this course. Kindly help.   Linear regression to minimize the Cost Function: $$J(\theta_0, \theta_1) = \frac{1}{2m} \sum_{i=1}^m \left(h_\theta(x_i) - y_i \right)^2 $$                Hypothesis of linear model is  $$h_\theta(x) = \theta \cdot x = \theta_0 + \theta_1 x_1$$  How to read this formula? What are $h_\theta$, $x_i$ and $y_i$?  How to make a decision which data has to go with this parameter?  Why 1/2m?


Proof of address for UK visa applications and correcting clerical errors

I have made an error filling the UK visa form. In the address section I have typed in my address (I live in Australia) correct including post code but selected a different country. I have my appointment to submit the printed copy of the application and supporting documents next week. What are my options to correct it?   Can I cut off the incorrect country in the address and hand write the correct one and then sign there? Am I able to make changes on the printed copy? I'll be submitting my drivers licence copy as proof of address. So would this matter?


I am using latest Ubuntu version. I'm having 64-bit system. When I run sudo apt-get update I get the below errors at the end of the result.  ... Get:79 http://us.archive.ubuntu.com precise/universe Translation-en [3,341 kB]  Get:80 http://us.archive.ubuntu.com precise-security/main i386 Packages [848 kB] Ign http://us.archive.ubuntu.com precise/main Translation-en_IN                 Ign http://us.archive.ubuntu.com precise/multiverse Translation-en_IN           Ign http://us.archive.ubuntu.com precise/restricted Translation-en_IN           Ign http://us.archive.ubuntu.com precise/universe Translation-en_IN             Fetched 30.0 MB in 13min 1s (38.4 kB/s)   W: GPG error: http://extras.ubuntu.com precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192 W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)  E: Some index files failed to download. They have been ignored, or old ones used instead.   I am not able to find the mistake I am making. I am not familiar with this command line. Please someone help me rectifying this.  thanks


If the friction coefficients depend on the object's property, why do they change in sliding & rolling, despite the object being same?

I know that when you roll an object instead of sliding it reduces the friction you can easily move an object. Consider the object to have a weight $W$ on a horizontal surface and the two objects have coefficient of friction of $\mu$. Thus the friction force $f$ should be: $$f=\mu W$$ In order for the friction to change, either $\mu$ or $W$ has to change and since $W$ does not change when rolling $\mu$ changes. My question is ,$\mu$ depends on the property of the materials not their orientation or their surface area of contact. So what has changed in order for $\mu$ to change? Does $\mu$ depend on other factors. The same question for static friction $\mu_{s}$and kinetic friction $\mu_{k}.$


How to restrict some websites in Ubuntu 14.04

I would like to restrict some websites to be surfed. I mean I want to prevent access to some websites. Please guide me on how to do the same in Ubuntu 14.04 LTS.


Is "propped up" an adjective or a past participle?

I am analyzing the past tense of "simple past" and I do not know if the form "were propped up" indicated in the sentence is composed of a verb conjugated in "simple past" and followed by an adjective, or on the contrary, it is part of a clause in passive.  Her flat cloth slippers were propped up on a foot-warmer, and a cat reposed on her lap.


Need to validate an input using Regular expression   It should accept only digit Min and max should be dynamic   Thanks for your help in advance  My code is  min=3, max=10   MyRegex is   /^(\d{min, max})$/


find all files containing all specified words

How can I use grep and/or find to find all files which have all of specfied words?  So something like   grep -R -words 'Quick', 'Lazy', 'Jumped' /   would return all files on system with words Quick, Lazy and Jumped.  Is there any support or should I be looking to write my own script?


Need help identifying a fantasy trilogy with a young woman protagonist

I cannot remember the author's name nor the titles of any of the books.    What I do remember is that the main character is a young woman who, I believe, dreams of an alternate reality.  There are hints throughout that the dream is really happening.    I do recall one scene in which the young woman finds a magician from this alternate reality in her kitchen.  I know it's not much to go on but any help is appreciated.  Thank you.


What is the important aspect to consider when deciding where windows interaction buttons should be placed?

In most windows desktops the minimize, maximize and restore buttons for a window are placed in the windows decoration on the top right. However, MacOS and now Gnome in Ubuntu have placed those buttons on the left.  What is the important aspect when deciding where to place them? Is user expectation from previous experience the most important aspect, or are there other independent aspects that relate to where the user would first look automatically? Is there a difference for localizations where the letters are written from left to right, or from right to left?


Why are RSA key sizes almost always a power of two?

I know that other bit sizes are possible, e.g. this HTTPS server seems to have a 9000 bit key , but it's very rare that one sees a key not of size 1024, 2048, 4096, etc. bits in common usage - what is the reason for this? Is it just customary, or is there a cryptographic advantage?


Mean or sum of gradients for weight updates in SGD

I am using single observation to compute losses using neural network implementation in PyTorch. I am confused in a small detail of SGD. If I compute loss and do loss.backward(), I am accumulating gradients.  If I do this on 100 observations and then run optimizer.step(), should I average out the gradients?  This is what I am doing as of now:  def compute_loss(training_data):   for data in training_data:     loss = F.mse_loss(data[0], data[1])     loss.backward()  def optimize(sample):   optimizer.zero_grad()   compute_loss(sample)   optimizer.step()   Should it be rather:  def compute_loss(training_data):   for data in training_data:     loss = F.mse_loss(data[0], data[1])     loss.backward(torch.Tensor([1.0/len(training_data)]))


Using R to subtract polygon area of one shapefile from another?

I'm looking to produce a map from two separate maps in R. My Maps files are as follows:   #Map1  #Map2  These are 6-10 day weather Precip maps from NOAA.   I would like to create a map with the area showing, being only the difference of the two maps. So Map1 - Map2 = Map3.   Also, I would like it to show the relative strength of the change for the above or below normal moisture. Which can be seen in the "Prob,N,13,11" & "Cat,C,254" files of the dbf file.   Without success I have tried:  converting to PolySet and then using joinPolys with the Operation="DIFF".  Also: using readOGR, checking for gIsValid, and then trying to use gDifference.  When I run the second one I get this error:     Error in RGEOSBinTopoFunc(spgeom1, spgeom2, byid, id, drop_not_poly, "rgeos_difference"):    TopologyException: no outgoing dirEdge found at -168.86604844949545 63.300706978948405   I am sorry if it seems like such a simple question of taking the difference between two maps but I have been stuck on this question for a number of days now.


How can one find out the value of $43^{1234567890} \mod 22\;?$  Can I just say that because $123456890$ is an even number I can calculate $43^2 \mod 22$, which is $1$?


When does combat begin and end during a dungeon?

I am a first-timer trying to prepare to host my first D&D night as DM with a bunch of curious friends (also first-timers in roleplaying).  I got the Starter Set so I'll be trying to play the Lost Mine of Phandelver campaign. After reading the Starter Set Rulebook and the first chapter of the campaign book, I find myself wondering about turns and time.  Are there still turns between encounters inside a dungeon? Are the player characters limited by their speed while moving in the dungeon out of combat?


is shell a command line interface if so why we need terminals

I have seen in linux the option "open in terminal" when you do right click. If shell itself is command line interface then it can by its own take input from keyboard and display it in console. Then why we need terminal or terminal emulator.  I know there is a similar question but the answer is not clear from the explanation provided here:


Show that ($\mathscr{P}(\Bbb{R})$)' and $\Bbb{R}^\infty$ are isomorphic.

Apologies for any bad formatting. This is number 35 from chapter 3.F of Axler's Linear Algebra Done Right, if you have the text to view. I've been stuck on this one for quite some time: obviously because the vector spaces are infinite dimensional, we cannot create the isomorphism using bases of the spaces. Also, because $\Bbb{R}^\infty$ contains infinite sequences, it is not clear to me how to create an injective function... I also thought that maybe I could develop the isomorphism using finite dimensional subspaces of the respective spaces, which is relatively easy, but being able to abstract that iso for the infinite dimensional spaces is beyond me. Any assistance/explanation would be greatly appreciated.


First of all, my apologies if it looks like a duple of , but since this question dates from more than 2 years, I thought it could be worth mentioning here.  I have this number "1" since last week:    And when I click on it, I go to this page:    First I thought it will disapear by itself, but since it still there, I thought it is probably a bug that I might report.    EDIT: The answer of the  question says:     This indicator is shown only to moderators and users who've gained access to the moderator tools.   As I didn't reach the requested 2k rep points, I did not have access to the moderator tools.  You can see I have not access to moderator tools:


Exception at mydrawer.setDrawerListener(myactiontoggle) in Android

I am using drawer in my project but sometimes it throw NullpointerException, below is my code where I got exception:  DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);     toggle = new ActionBarDrawerToggle(TabSample.this, drawer, null, R.string.navigation_drawer_open, R.string.navigation_drawer_close);     drawer.setDrawerListener(toggle);//here i got exception     toggle.syncState();   And the below error i got:      01-23 11:53:20.370 16530-16530/com.myproject.myproject1 E/AndroidRuntime: FATAL EXCEPTION: main     java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myproject.myproject1/com.myproject.myproject1.TabSample}: java.lang.NullPointerException     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)     at android.app.ActivityThread.access$600(ActivityThread.java:128)     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)     at android.os.Handler.dispatchMessage(Handler.java:99)     at android.os.Looper.loop(Looper.java:137)     at android.app.ActivityThread.main(ActivityThread.java:4517)     at java.lang.reflect.Method.invokeNative(Native Method)     at java.lang.reflect.Method.invoke(Method.java:511)     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)     at dalvik.system.NativeStart.main(Native Method)     Caused by: java.lang.NullPointerException     at android.support.v7.app.ActionBarDrawerToggle$HoneycombDelegate.setActionBarUpIndicator(ActionBarDrawerToggle.java:539)     at android.support.v7.app.ActionBarDrawerToggle.setActionBarUpIndicator(ActionBarDrawerToggle.java:458)     at android.support.v7.app.ActionBarDrawerToggle.syncState(ActionBarDrawerToggle.java:245)     at com.myproject.myproject1.TabSample.setDrawer(TabSample.java:109)     at com.myproject.myproject1.TabSample.onCreate(TabSample.java:77)     at android.app.Activity.performCreate(Activity.java:4470)     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)      at android.app.ActivityThread.access$600(ActivityThread.java:128)      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)      at android.os.Handler.dispatchMessage(Handler.java:99)      at android.os.Looper.loop(Looper.java:137)      at android.app.ActivityThread.main(ActivityThread.java:4517)      at java.lang.reflect.Method.invokeNative(Native Method)      at java.lang.reflect.Method.invoke(Method.java:511)      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)      at dalvik.system.NativeStart.main(Native Method)       please help to solve his NullpointerException in ActionBarDrawerToggle.  This question not just about NullpointerException exception as tell me duplicate like:


I tried installing rails according  to , and when I do, I get this error:  $ sudo gem install rails   WARNING:  Error fetching data: Errno::ENOENT: No such file or directory - getaddrinfo (http://rubygems.org/specs.4.8.gz)   WARNING:  Error fetching data: Errno::ENOENT: No such file or directory - getaddrinfo (http://rubygems.org/latest_specs.4.8.gz)   Building native extensions.  This could take a while...   ERROR:  Error installing rails:       ERROR: Failed to build gem native extension.            /usr/bin/ruby1.9.1 extconf.rb   /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)       from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'       from extconf.rb:1:in `<main>'     Gem files will remain installed in /var/lib/gems/1.9.1/gems/json-1.8.0 for inspection.   Results logged to /var/lib/gems/1.9.1/gems/json-  1.8.0/ext/json/ext/generator/gem_make.out   I've never seen anything like this before, so any feedback would be greatly appreciated.


My browser is Firefox, with 3 open tabs:  tab1-->google.com tab2-->yahoo.com tab3-->msn.com   All of them use port 80, and so does Photoshop:  How does computer know which data belong to which process?


Does somebody has an example where the left $R$-modules $R^m$ and $R^n$ are isomorphic for all positive integers $m$, and $n$?


How to add an Event Listener to a div only when a specific class is "toggled" on?

I am trying to exit the popup card by clicking anywhere other than the card i.e. on the blurred background, but I am not able to add the EventListener to the div, because the class is toggled off and the error is Cannot read property 'addEventListener' of null at... This code doesn't work. const blurMe = document.querySelector(".blur"); blurMe.addEventListener("click", function () {         for (let index = 0; index < 3; index++) {             card[index].classList.add("hidden");         }         blurMe.classList.remove("blur");  });   My cross button is working fine but I don't know how to add the feature to exit the popup just by clicking anywhere else on the screen.  please add the code to


Just curious if you ever found where to buy those spatulas? (Re: Where did the thin, smooth plastic spatulas go? The dark blue one on the left)   My wife would like to get some too but I can't find that type either.  Thanks for any help.


What causes the blur when my fingers are almost touching?


Equivalent for "both" for three or more entities

Which words could I use for (1) and (2) below:     two => both   three => (1)?   four => (2)?   To use them in phrases like these:     both A and B   (1) A, B and C   (2) A, B, C and D   Please give single words if possible.


How to select minimal (maximal) of each matched rows in one to many relation?


For positive real numbers $x_1,x_2,\ldots,x_n$ and any $1\leq r\leq n$ let $A_r$ and $G_r$ be , respectively, the arithmetic mean and geometric mean of $x_1,x_2,\ldots,x_r$.  Is it true that the arithmetic mean of $G_1,G_2,\ldots,G_n$ is never greater then the geometric mean of $A_1,A_2,\ldots,A_n$ ?  It is obvious for $n=2$, and i have a (rather cumbersome) proof for $n=3$.


Is there a shortcut (key combination) in emacs to repeat the second last command? Or third last command and so on? I know that Ctrl + x +  z   can be used to invoke the last command, but could not find a key combination for others!


Prove that the identity map is continuous

Hello I have problems with exercise Let $\tau_1$ and $\tau_2$ be given topologies on a set $X$. Prove that the identity map $(X, \tau_1) → (X, \tau_2)$, $x   \longmapsto x$, is continuous if and only if $\tau_1$ is finer than $\tau_2$ My attempt: $\Rightarrow{}$) We have the function is continuous then $\tau_1 \subseteq{\tau_2}$ $\therefore$ $\tau_1$ is finer than $\tau_2$ $\Leftarrow{}$) By hypothesis $\tau_1$ is finer than $\tau_2$  then $\tau_1 \subseteq{\tau_2}$. Le the function defined by $(X, \tau_1) → (X, \tau_2)$, $x   \longmapsto x$ I don't know how to continue Thanks


How is this interface being instantiated?

This is from the Minecraft server source code, also called the Minecraft Bukkit API, now you know as much as I do.  There is an interface called Server:  public interface Server extends PluginMessegeRecipient {     public String getVersion(); }   PluginMessageRecipient  is an interface also.  There is a class called Bukkit that instantiates Server:  public final class Bukkit {     private static Server server;  }   Inside methods in the Bucket class they invoke methods from the server object. For example:  server.getVersion();   The thing is, there is no code for getVersion in the Server interface, just a method signature. There is also no code in the PluginMessageRecipient interface nor does it extend anything.    I have read all the questions and answers on SO that say I need an anonymous class or an inner class and this does not seem to fit those solutions.


How to solve this limit (with factorial)?

How to solve this limit??  $$\lim_{k \to \infty} \frac{(2k)!}{2^{2k} (k!)^2}$$  It's a limit, not a series