Why C doesn't allow implicit conversion from char ** to const char *const * (and C++ does)?

I know implicit conversion from char ** to const char ** cannot be done and why, and that the conversion to char *const * works.  See bottom for links to explanation on that.  It all makes sense apart from one particular thing.  So I have the following code:  #include <stdio.h>  void print(const char *const*param) {     printf("%s\n", param[0]); }  int main(int argc, char **argv) {     print(argv);     return 0; }   If I compile this as a C++ code, it compiles quite fine.  However, if the same code is compiled as a C code only, I get an error (well, a warning, but let's suppose -Werror, i.e. treat warnings as errors).  gcc:  test.c: In function ‘main’: test.c:12:11: warning: passing argument 1 of ‘print’ from incompatible pointer type [-Wincompatible-pointer-types]      print(argv);            ^ test.c:4:1: note: expected ‘const char * const*’ but argument is of type ‘char **’  print(const char *const*param)  ^   clang:  test.c:12:11: warning: passing 'char **' to parameter of type 'const char *const *' discards qualifiers in nested pointer types [-Wincompatible-pointer-types-discards-qualifiers]     print(argv);           ^~~~ test.c:4:25: note: passing argument to parameter 'param' here print(const char *const*param)                         ^   Both behaviours are standard-independent and also compiler-independent.  I tried various standards with both gcc and clang.  There are two reasons for this inquiry.  Firstly, I want to understand whether there is a difference and, secondly, I have a function that does nothing with any layer of the pointers and I need it to be able to work with const char ** as well as char *const * and char **.  Explicitly casting each call is not maintainable.  And I have no idea how should the function prototype look like.    This is the question that started my curiosity:   And here is another nice explanation for the char ** => const char** problem:   If the links are confusing related to this question, feel free to edit them out.


File.getName() not comparing properly to a String

I have an arrayList in a class and a getter for it. I need to make a method that returns an arrayList filled with all the files from the first arrayList that have the same name as the String arg. This is what I've come up with.  ArrayList<File> dirs = new ArrayList<File>(); // filled with files  public ArrayList<File> getDirectoriesNamed(String fileName) {     ArrayList<File> files = new ArrayList<File>();     for (File file : dirs) {         if (file.getName() == fileName) //problem is here             files.add(file);     }     return files; }   however when I try this, I get an empty arrayList. and I figured out that the reason is because of the if Statement... is there any reason why that shouldn't work that I'm not seeing?


I am trying to build a simple LinkedList in Java which takes chunks of a String. I am getting NullPointerException when i try to pop the elements. Below is my code. Please help me out.  public class LinkedList {      private class Node {          private String info;         private Node next;          Node() {             this.info = null;             this.next = null;         }          Node(String item, Node next) {             this.info = item;             this.next = next;         }      }      // private Node start;      Node start = new Node();     Node end = new Node();     Node top;      public void addNode(String item) {         if (start.next == null) {             top = new Node(item, end);             start.next = top;             return;         }          if (start.next != null) {              top.next = new Node(item, end);             top = top.next;             // top.next = end;          }     }      public String[] pop() {         String[] result = null;         Node popping = start;         while (popping.next != end) {             popping = popping.next;             int count = 0;             System.out.println(count);             result[count] = popping.info;              count++;         }          return result;     }      public static void main(String args[]) {         LinkedList kds = new LinkedList();         for (String s : "kds on a roll".split(" ")) {             kds.addNode(s);             // System.out.println(kds.toString());         }          String[] s = null;         System.out.println("Popping Begins");         s = kds.pop();         System.out.println(s);     } }


Trouble proving a function homeomorphism in S. G Krantz's Topology

I am learning Topology from SG Krantz ( Dolciaini expository text) and I am unable to prove the function in following example to be homeomorphism.   I am unable to prove it either 1-1 or onto. I have proved it continuous.  Inverse of f is  ($ \frac{y} {\sqrt{ \frac{t^2} {x }-1}}$,$ \frac{x} {\sqrt{ \frac{t^2} {y }-1}}$). It is continuous everywhere when x$\neq$ t or -t or y$\neq$ t or -t. But I have no reason to believe that it must happen. S It's my humble request to help proving me 1-1 , onto and continuity of inverse. Thank you.


How to replace OS drive with an SSD on a laptop

I have an laptop that is ~ 4 years old. It has 2 hard drives - one is used for the OS and the other for data.  I'd like to upgrade the OS drive with an SSD to make it run faster, but i was wondering whether i would have to install the OS (Windows 10) all over again, or whether there's an easier option ?


For $n=3,$ $L$ matrix is as below:  $$ \left[\begin{matrix} 1&0&0\\ -1&1&0\\ -0.5&-0.5&1\\ \end{matrix}\right] $$  for $n=4$ we have:  $$ \left[\begin{matrix} 1&0&0&0\\ -1&1&0&0\\ -0.5&-0.5&1&0\\ -1/3&-1/3&-1/3&1 \end{matrix} \right] $$  and for $N$th we have: $$ \left[ \begin{matrix} 1&0&0&0&\cdots&0&0\\ -1&1&0&0&\cdots&0&0\\ -0.5&-0.5&1&0&\cdots&0&0\\ \vdots&\vdots&\vdots&\vdots& & \vdots&\vdots\\ -1/(N-2)&-1/(N-2)&-1/(N-2)&-1/(N-2)&\cdots&1&0\\ -1/(N-1)&-1/(N-1)&-1/(N-1)&-1/(N-1)&\cdots&-1/(N-1)&1 \end{matrix} \right] $$  How to get the roots (eigenvalues) of the $N$th order of the $L+L^T$ matrix? is there a specific logic between the roots of this matrix?


Heartbleed: are services other than HTTPS affected?

The OpenSSL 'heartbleed' vulnerability () affects webservers serving HTTPS. Other services also use OpenSSL. Are these services also vulnerable to heartbleed-like data leakage?  I'm thinking in particular of   sshd secure SMTP, IMAP etc -- dovecot, exim & postfix VPN servers -- openvpn and friends   all of which, on my systems at least, are linked to the OpenSSL libraries.


How should I used two MLX90614 sensor on one Arudino Uno given that the sensor has a fixed I2C bus adress?

I have an arduino uno and want to use a non MLX90614. I plan to used more than one sensor on the same Arduino but I don't know how to use two MLX90614 on the same I2C bus.


Easier way of placing a figure over and between columns

I'd like to reproduce a three-column document which contains figures that span the middle column and also protrude slightly into the left and right columns.  The text wraps around the figure.  Here's an example which was fairly simple to mock up in a word processor:    The wrapfig package contains some relatively obscure instructions, not in the main documentation but tucked away in the text file , which explain how to do this manually.  The process is somewhat tedious.  However, that documentation dates from 2003.  I was wondering whether, in the intervening 12 years, anyone has come up with a more convenient way of doing this.


Python difference between method and lambda

What are the possible niuances (differences) between a method and a lambda? I have an identity function and wonder does it make much of a difference how I define it?  def ident(x): return x ident = lambda x: x   These are surely functionally the same, but do they differ in performance or otherwise?


Will 16.04 LTS ISO image be modified to include Spectre and Meltdown fixes?

was about to download and install Ubuntu a week or so ago, then Spectre and Meltdown issues came to the fore and I decided to wait. Will the LTS ISO image available for download be patched? If so, I'd prefer to wait for a short while until that happens. If it's not going to be patched, and I install from the LTS iso downloaded from Ubuntu site, will the update come automatically, or will I be on a learning curve to manually update? Thanks


Let $p$ be prime and $p\ge5$. My friend askes me the following  $\sum\limits_{k=0}^{\frac{p-1}2}3^k\binom{p}{k}\equiv 2^p-1\pmod{p^2}$.  Here $\binom{p}{k}=\frac{p!}{k!(p-k)!}$ for any $k=0,\ldots,p$. We define $0!=1$.   I think this is true, but I have no idea to attempt it.


How to apply materials to specific faces only?

I imported an object with many faces and materials, but I only want some materials to apply to certain faces, how could I do this? When I add the material, it adds it to the entire thing, how do I do it for one face?


Who can prove that a triangular number cannot be a cube, fourth power or fifth power?

Triangular numbers (See   )  are numbers of the form $$\frac{n(n+1)}{2}$$  In ProofWiki I found three claims about triangular numbers. The three claims are that a triangular number cannot be a cube, not a fourth power and not a fifth power. Unfortunately, neither was a proof given nor did I manage to do it myself. Therefore my qeustions :     Does someone know a proof that a triangular number cannot be a cube, a fourth power or a fifth power ?


why non english letter render gibberish in HTML?

I am defining a element in html

  and I am setting the inner html like this document.getElementById("dict").innerHTML=
ಒಂದ್
;  but the render is gibberish à²’à²‚à²¦à³  expected result ಒಂದ್  what am i missing here?


I am trying to get Anki to work with LaTeX. I have a custom card type with the following header: \documentclass[12pt]{article} \special{papersize=3in,5in} \usepackage[utf8]{inputenc} \usepackage{amssymb,amsmath,amsfonts} \pagestyle{empty} \setlength{\parindent}{0in} \newcommand{\OO}{\mathcal{O}} \usepackage{stmaryrd} \begin{document}  and footer: \end{document}  I have a cloze card in my deck with the following code: [latex]{{c1::Test}}[/latex]   When I try looking at the card, I get a broken image icon, and below that, the following message:  Error executing latex. Generated file: /tmp/anki_temp/tmp.tex Have you installed latex and dvipng/dvisvgm?  I am using Kubuntu 20.04. I have texlive-full, dvipng as well as dvisvgm installed. The LaTeX code used on Anki cards compiles without problems in TeXStudio. The problem is only present on cloze cards: basic cards are displayed properly. There are several questions of this sort on this and other sites, however none of the answers there solved my problem.


Prove: $1/2(a+b) \times (a - b) = b \times a$ - in three space

Let $\times$ = cross product and $a$ and $b$ have vector signs on them.  $a = [a_1, a_2, a_3]$  $b = [b_1, b_2, b_3]$  How would I prove this? Do I expand out cross product?  Any help is appreciated!


Java Random : How to return int value with non significative 0

I need to get a random value between 0 and 100 in String format. I use Random class, but when i cast the result in String, the non significative 0 are not kepped.  sb.append((rand.nextInt(99)));  Is there a method in StringBuilder or Random for force the result with this 0 ?


Restore Verify Only option vs Manual Restore

My question is related to best practices with SQL Server. I need to put together a document that lists our various databases and that the backups we have of these databases are valid and have been tested and we know that they will restore properly in case of a disaster recovery scenario. I'm using the Ola H. maintenance solution which backs up the databases with the RESTORE VERIFY option and gives a "succeeded" message to indicate that the backupset is valid. Is this enough to be confident or should we still be manually restoring these backups to a test server and running tests?


Example of Erdos-Szekeres bound being tight

I know that Erdos-Szekeres Theorem states that any sequence of $k^2+1$ real numbers contains a monotonic subsequence of length at least $k+1$.  I know that it is a least upper bound since there exist sequences of $k^2$ real numbers that do not contain a monotonic subsequence of length $k+1$.   First, I was asked to prove the Erdos-Szekeres Theorem in two different ways, which was done accordingly. Then, I was asked to  Describe an example which shows that the bound given by the Erd}os-SzekeresTheorem is tight.  I have little clue on how to approach this. Any suggestions?


Revisiting producing structured PDFs from LaTeX

I am trying to produce a structured or 'tagged' PDF from pdftex (Tex Live 2013) that passes automated tests in Adobe Acrobat for tagging. These tests are the de facto indicator for a document accessibility, which are often required by universities, government agencies and others worldwide for published documents.  To test a document for accessibility / tagging, try this:   Open the PDF in Acrobat Reader 'file -> 'document properties' -> 'Description' under 'advanced', you'll see a field, 'tagged pdf'. Ideally it should say 'yes'. But it doesn't :(     Question: does anyone know of any way to create a PDF which passes Acrobat's 'Tagged PDF' test directly from LaTeX?  The ideal solution would be a package or two that can be called from the preamble of a latex document. I want something that is very low effort for the author, and can thus be very easily integrated with .  Note: There has been discussion about this in the past (see tags and links on the right), but as of May 2014, there was no clear solution to this. Much of the existing discussion is from 2012 or earlier (see ), and so I'd like to see if we can kick-start this discussion.  Why this isn't a duplicate question: When I first posted this question in July 2013, it was flagged as a duplicate of . The answer references a presentation given at at TUG 2010. That presentation basically says "we're working on it", and is not an answer that allows me to implement a solution.  Because it is now 2014, I think it reasonable to expect that:   There have been new developments in this field through new packages or updates to core LaTeX Attempting to comply with Section 508 will have required that people figure out solutions. This is a relatively recent requirement and so solutions may have changed since 2010 The software that is typically used to judge compliance (Adobe Acrobat) has changed several times since the question was not answered Packages that address accessibility have been proposed but not come in to widespread use or even disappeared (e.g. the accessibility package, ), and it is therefore reasonable to revisit this issue with fresh eyes.


Is the lifetime of the temporary string long enough here?

#include <cstdio> #include <string>  std::string foo() {     return "Hello, World!"; }  int main() {     printf( "%s\n", foo().c_str() ); }


Objects appear textureless/invisible in EEVEE viewport (Blender 2.91)

Whenever I try to view my scene in EEVEE via the viewport, my model's textures all of a sudden. I tried reverting back to the factory settings but to no avail. It seems to also be a problem in the material preview viewport.  I can't show it due to an NDA but the texture works fine in the Cycles render viewport. My specs are: CPU: Intel Core i5 4590 GPU: AMD Radeon RX 560 8GB DDR3 Ram All stored in an SSD


Where can I ask for a programming "idea", as I am stuck at somepoint in my project?

Is it okay if I ask a question on Stack Overflow about the concern I have in my project? I am midway and unable to figure out how to move ahead.  I am not looking for someone to write and give code for me, but I am stuck at some point where I am unable to understand how to proceed, as it includes different programming languages/nosql database.  Or to put it in another way, where can I ask such question?


How to immediately (temporarily) install a Windows Server 2012 R2 Foundation and upgrade later to the ROK version?

A friend of mine has to set up a Windows server box and is in a hurry – the server must be running asap. He has successfully ordered a IBM System x3100 M5 with appropriate RAM and HDDs. However, there are difficulties in the delivery of the recommended operating system version, which is IBM Windows Server 2012 R2 Foundation, ROK, 1 CPU (the OS can be delivered but it will arrive a couple of days too late).  Because of the fact that I am a Linux guy, I am not too familiar with Microsofts licensing options and restrictions. Firstly, I am not sure if I really need IBM's ROK version for successful operation of the server (does it include important drivers that other distributions lack?). Secondly, I am not entirely sure if I could simply install an evaluation version first, and later on use the product key of the IBM Windows Server 2012 R2 Foundation, ROK, 1 CPU as soon as it has arrived (there seem to be only evaluation versions of the Essentials/Standard/DataCenter, but not for the Foundation). Would a Windows Server 2012 R2 Essentials work as well for my server? Does it include all required drivers?  So how should I tackle this situation? My favorite option would be to (of course legally) buy-download-burn the IBM Windows Server 2012 R2 Foundation, ROK, 1 CPU somewhere, but it seems that this is not offered. My second favorite alternative would be to download and burn a Windows Server version which can be migrated later on to the supported version. But I am a bit lost in Microsofts version and license jungle.


Wrong value when event handlers are attached in a for-loop

I want to create some Box objects inside an array. In the begining I initialized these objects in a for-loop, attaching also an event handler which passes the current index i.  int[] boxes = new int[9]; for (int i = 0; i < boxes.Length; i++) {   var b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(i, e.Marking);   boxes[i] = b; }   private void OnBoxMarkOccupied(int position, Marking marking) {   BoxOccupiedEvent?.Invoke(this, new BoxMarkingEventArgs(position, marking)); }   I am expecting that when MarkingOccupiedEvent of boxes[0] is raised then I am going to retrieve a position equals to 0 from BoxMarkingEventArgs. All I am getting though is the value of 9. And this applies to all boxes inside the array, not just the first one.  Out of curiosity I deleted the code in the loop and wrote the initialization code by hand (since it's only 9 boxes),    var b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(0, e.Marking);   boxes[0] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(1, e.Marking);   boxes[1] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(2, e.Marking);   boxes[2] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(3, e.Marking);   boxes[3] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(4, e.Marking);   boxes[4] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(5, e.Marking);   boxes[5] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(6, e.Marking);   boxes[6] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(7, e.Marking);   boxes[7] = b;    b = new Box();   b.MarkingOccupiedEvent += (s, e) => OnBoxMarkOccupied(8, e.Marking);   boxes[8] = b;   Guess what, that code works!   What is wrong with the approach using the for-loop?


I have a code that first receives an input from the user and then counts how many " ) " and " ( " there are in the input:  Scanner in = new Scanner(System.in); String input = in.next(); String[] array = input.split(""); int countS = 0; int countH = 0;     for(int i = 0; i < input.length(); i++){     if(array[i] == ")"){         countH ++;     }     else if(array[i] == "("){         countS ++;     } } System.out.println(countH); System.out.println(countS);   I what to know what's wrong with the program. All help is appreciated!


can i dual boot ubuntu and kali linux on a externel hard disk drive? if so how?

i am currently using linux mint 20 but i want to make it windows 10 and want to dual boot ubuntu and kali linux on my external HDD. Is this possible?


My Hashtable in Java would benefit from a value having a tuple structure. What data structure can I use in Java to do that?  Hashtable<Long, Tuple<Set<Long>,Set<Long>>> table = ...


Finding and Deleting duplicate rows in table where multiple occurances of records is allowed

I have a table that I need to delete duplicates. However, the table is designed so that each customer can have identical items. Here is a screen shot for example:    When I try to delete duplicates I also get Book Number that are the same for both customer. The Green area shows actual duplicates, however the blue shows books that are not duplicate because customers can borrow the same books.  How do I delete only where the row is the same for each customer? So the green area.  Here is my code: It does not work if both customer has the same Book number.  WITH CTE AS ( SELECT  *,  ROW_NUMBER() OVER (PARTITION BY BookNumber ORDER BY BookNumber DESC) AS DUPS FROM Store.Books  )  SELECT * FROM CTE WHERE DUPS > 1


Component Event doesn't seem to working!

I was testing passing data between two components using Component Events but something doesn't seem to be right. I am not able to get the value in the Handler component. Could someone let me know what i did wrong here?  Event: EventForCompEventsApp2.evt  <aura:event type="COMPONENT" description="Well, Hello there! I'm Event" > <aura:attribute name="message" type="string" />     Event Registered Comp: CompForEventRegistering.cmp      <aura:component >     <aura:registerEvent name="compEvent" type="c:EventForCompEventsApp2" />          <aura:attribute name="myText" type="string" default="John" />

EVENTS

COMPONENT EVENT TESTING

      <lightning:layout horizontalAlign="spread" multipleRows="true">         <lightning:layoutItem flexibility="auto" size="6" largeDeviceSize="2" padding="around-small">             <ui:inputText label="Enter some text" class="field" value="{!v.myText}" />             <lightning:button label="Add Text" onclick="{!c.takeInput}" />         </lightning:layoutItem>     </lightning:layout> </aura:component>   Controller for above comp:      ({     takeInput : function(component, event) {         var enteredText = component.get("v.myText");         console.log(enteredText);         var appEvents = component.getEvent("compEvent");         //appEvents.setParams({"message" : enteredText});         appEvents.setParams({"message" : enteredText});         appEvents.fire();         console.log("MEssage is **-->"+appEvents.getParam("message"));     } })   Event Handler Comp: CompForEventHandling.cmp      <aura:component >      <aura:attribute name="myAnotherText" type="String" default="**nothing fired yet**" />     <aura:handler name="cmpEvent" event="c:EventForCompEventsApp2" action="{!c.handleEvent}"/>
First Name
             <ui:outputText value="{!v.myAnotherText}" /> </aura:component>   Controller:   ({     handleEvent : function(component, event, helper) {         var capturedText = component.get("v.myAnotherText");         var theMessage = event.getParam("message");         console.log('MESSAGE IS--->'+theMessage);         component.set(capturedText, theMessage);     } })   And the Result:


Area 51 rep is not displayed in communities list

As you see. What can be the reason? I added it to communities list about a week or two ago.


Could Mars be used to measure the one-way speed of light?

I just watched  explaining the difficulty of measuring the one-way speed of light.  The presenter explains that a round-trip will always average out to $c$ even if the speed in one direction isn't always the same as the speed in a different direction.  He used the example of an astronaut on Mars synching his clock with Earth, and how different aberrations would still always make it end up looking like it was consistently $c$. But the example of Mars got me thinking.  Mars has two interesting properties: it's far enough away from Earth that there's a very noticeable time delay, and it's in a different orbit around the sun than we are, so its direction relative to us is constantly changing.  So here's an experimental proposal that doesn't require any synchronization:  Put a radio beacon on Mars that pulses in a regular, well-defined rhythm, then observe it from Earth for a Martian year or three. No clock synchronization is necessary; just observe the rhythm.  If the speed of light is not constant in all directions, this will create a Doppler effect in the pulses that can't be explained simply by the movement of the two planets.  If no such Doppler distortion is detected, we can safely conclude that the speed of light is invariant in different directions.  (Or at least in all the directions along the essentially 2-dimensional orbital plane of Sol.) Is there anything that would cause this experiment to not produce correct results, if it were tried?


Active Calories VS Total Calories during a workout

I'm fairly new to the Apple App- I was a Fitbit user and Fitbit reflected Fat burn, active minutes and Peek time during a work out.  Apple app reflects Active Calories and Total Calories during a work out and I am not able to find an answer to define the difference.  what is the difference in a work out from Active vs Total.  I am still on the fence about this app, fitbit showed when during my work out my heartrate increased, and clearly reflected the calories -


Minor edits should be easy.  I don't mean trivial edits, but rather low character count grammar and spelling edits.  Changing a few characters to clean up the site makes the Internet better.  Discouraging users from making productive minor edits allows ugly obvious errors to persist.  Many answers or comments on questions on this subject are awfully negative: e.g.,              If someone sees a minor error and wants to fix it, why would we stop them?  If the issue is rep, just don't give any for such edits.  If the issue is bumping, don't bump such edits.  If the issue is that too many people have to review the edits, lower the rep limit for minor edits.  If you think that 2k rep users will somehow find it on their own or that flagging is the proper solution, you're introducing unnecessary bureaucracy.  If you think that everyone can see a grammatical error without cringing, you don't know developer types.  If you assume that there's always five more characters to change, you're encouraging gaming of exactly the sort you're trying to avoid.  Surely there's a better way?


tell me where I am or where am I? In this situation

So couple of my classmates are chatting in a group & ...   A: Turn off your GPS, now everyone knows where you are!  B: Ok then tell me where I am/where am I?  Which one is correct in this situation?  My thought was because she already knows where she is, tell me where I am is the correct response here.


What happens to a radioactive element or isotope's electrons when it undergoes alpha decay?

It seems to make sense that when an atom loses two protons, it would lose two electrons as well, but I don't actually know what happens.


I have this iframe and put below it the script for a the .css() function to return some elements values inside the iframe but it's not functioning at all. Is it right how i set it? Any help appreciated.


In  of phone cameras I came across one data point that intrigued me: They appear to write the sensor size as a fraction, in this example 1/5.8". What exactly does that mean?  My hypothesis was that it was (1/5.8)" = 0.1724" = 0.4379cm, is this correct?  And if so, why would you write it as a fraction?


Proving that $S=\{\frac{1}{n}:n\in\mathbb{Z}\}\cup\{0\}$ is compact using the open cover definition

Let $S=\{\frac{1}{n}:n\in\mathbb{Z}\}\cup\{0\}$ be a subset of $\mathbb{R}$. I have to prove using the open cover definition that this is compact. Could you help me, please?


Is the use of the word "cracker" as a racial slur so common that it cannot safely be used to refer to certain hackers?

I always liked to use the word "crackers" to refer to people who overcome computer software or security restrictions, as opposed to "hackers," which (supposedly) originally meant people skilled at computing.  A while ago, I used the word in my conversation with a speaker of AmE, who did not know of that use of the word and thought I was using a racial slur.  This could have been a problem since I am not Caucasian myself.  While I could use other words like "script kiddies" to roughly mean what I meant by "crackers," this left me with the following question: is the use of the word "cracker" as a racial slur so common that it cannot be used to refer to certain hackers without causing misunderstanding?  My assumption is that it may depend on where you are: if you are in the Deep South, probably the word is more commonly used pejoratively than elsewhere.  But I don't know that for sure.


Using db_query() or db_select() to connect to multiple databases

How can I execute a query that connects to different databases?  I have the following query, and I need to rewrite it for Drupal.  SELECT a.empid, b.empname FROM db1..empidmaster a, db2..emplist b WHERE a.empid = b.empid   How can I rewrite the query using db_query(), or db_select()?


Bake Simple Deform animation into mesh for Unity3D export?

I'm trying to use a .blend file with a keyframe animation on the angle of a Simple Deform modifier in Unity3D. Unity3D however does not know how to handle modifiers and hence cannot play the animation.  How can I bake/save the animation to the .blend file so that Unity3D can play it?


The use of the word "the" with certain nouns

Specifically, British people go "to hospital", while American English speakers say "to THE hospital".  We say, "go to school", so why not "got to hospital"?


I am trying to create a formula field to count if there are any blank values on Number field.  My formula is :      if(ISBLANK(Number Field),1,0)   However, it is always coming as '0' even if the number field is having some value in the record.  Please advise as to where I am going wrong.


What should be the default option of a required dropdown list?

Given that there is no logically default animal from the list of animals below, what should be the "Default Value" below, according to best practice?  <label for="animal">Animal (required):</label> <select name="animal">   <option value="">Default Value</option>   <option value="0">Cat</option>   <option value="1">Dog</option>   <option value="2">Horse</option>   <option value="3">Pig</option>   <option value="4">Sheep</option> </select>   A blank value, <option value=""></option>?  Something visually irritating, <option value="">***CHOOSE ANIMAL***</option>?  Something which blends in but provides instruction, <option value="">Select an Animal</option>?  Something else entirely?


Add click event to trigger timestamp tooltips

I just cannot seem to get these to pop up on the stock Android browser or the latest Chrome for Android, in both desktop and mobile mode. Can a click event be added for these (and other tooltips/title text/alt text that are useful on the site)?


Most efficient way to append arrays in C#?

I am pulling data out of an old-school ActiveX in the form of arrays of doubles. I don't initially know the final number of samples I will actually retrieve.  What is the most efficient way to concatenate these arrays together in C# as I pull them  out of the system?


Hey guys im a window user and I just installed ubuntu into my lowspec laptop.  During the installation it was stucked in a place where it says "retrieving files 92 out of 123".  I restarted my laptop and put it back on installing again but same issue appeared.  Then I saw a skip button after pressing that everything went running again and after it got installed now I'm facing issues with installing anything from both the terminal or the software center, it says      unable to install "application name"   and after watching few tutorial from youtube things got worst: now it says something like   "E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.    Kindly help get rid of this problem thank you!


I want to retrieve information like the city, state, and country of a visitor from their IP address, so that I can customize my web page according to their location. Is there a good and reliable way to do this in PHP? I am using JavaScript for client-side scripting, PHP for server-side scripting, and MySQL for the database.


Showing that a composite number has a small prime divisor?

At the moment I'm working on proving some statements and I've run into one that I can't seem to wrap my head around. It goes like this:     For $n \in \mathbb{Z}^+$, we define $\sqrt{n}$ as the real number $a$ such that $a^2 = n$.    Show that if an integer $n > 1$ is composite, then it has a prime less than or    equal to $\sqrt{n}$.   So far I've really only been able to prove by example using certain numbers but apart from that I'm rather lost on how I should approach and prove the statement. Any suggestions or help is much appreciated.


If $a,b$ is an $R$-sequence, then $ax-b$ is prime (Eisenbud, Exercise 10.4)

This is the exercise mentioned above:     Let $a,b$ be regular sequence over a domain $R$. Prove that $ax-b$ is a prime of $R[x]$.   Thank you for your answer!


Writing someone else's master's thesis: Unethical and illegal?

It is really difficult for me to decide on this situation: when someone calls me and asks for work-for-hire for his/her thesis. I don't know what to do. I want to help and earn money but I think this way of earning money is unethical.  I think that receiving the title of thesis and giving back prepared manuscript is the intention that some people have, when asking for their thesis to be written.  There are plenty of websites offering such services!   The question is that: Is it legal and or ethical to write someone else's master's thesis as work-for-hire?


Creating a URL (and not necessarily a parameter list) using jQuery or JavaScript

I am communicating to a REST server which is expecting something like http://example.com/1.0/editor/5/bla/26 along with body parameters of x, y, and z.  Or maybe instead of /1.0/editor/5/bla/26, it should be 1.0/editor/5/bla/what about item #26, but of course with what about item #26 escaped.  There are many post describing how to use  to encode parameters, however, that is not my question.  How chould the actual url be created using jQuery of JavaScript?  $.ajax({     type:'PUT',     url:'/1.0/editor/'+$('#id').val()+'/bla/'+$('#wha').data('id'),     data:{x:x,y:y,z:z},     success: function (error){} });


Is "jipped" a politically incorrect word?

I recently read a line of chat conversation, where somebody said:      … get jipped by some guy …   A different user construed this as "casual racism", even though the whole conversation was completely unconnected to racial issues. It seems that the problem is the word "jipped" which Wiktionary says is      Probably from the term gypsy (“Roma”), due to a stereotype of the Roma as swindlers.   (emphasis mine).   So I wonder, is this really a politically incorrect word to use? Do speakers and listeners generally connect the word with actual Roma stereotypes? Or is it a rarity to think about its origins, and people generally just use it without thinking of the possible historical etymology, just like people use malaria without ever thinking of bad air?   I heard/read the word for the first time, and did not make a connection to "Gypsy" at all, even though I am European and I am generally aware that "gypsy" is a pejorative racial term.


is there an easy way or photoshop plugin to distribute words in evenly spaced formation

I try to do it mostly with words but sometimes have to do it with other things too. How do you equally space out things automatically, I Know how to evenly distribute from the center of every layer/object but not how to have even actual space between those to objects.   This is really not a problem when all the things are of the same width (or height) but as you know words are hardly ever that. So what i do is is make a rectangle of size that i want space to be empty and once done typing i manually drag out that box to the end of the first word, then adjust the 2nd one decrease/increase the space to match the edges of the rectangle and so on for the texts after 2nd..like 3rd,4th...Usually it's Home, About, Products, Contact, etc...


How can I flag a closed question for deletion?

On what basis can I flag for moderation attention to delete a closed question?   I know  between closed questions and deletion so now I just want to know how to phrase my reasoning for deletion.


let M be a set of those natural numbers that can be written using only 0's and 1's(in the decimal system).prove that for evey natural number k,there exist a number m ∈ M such that (i) m has exactly k 1's,and (ii) m is divisible by k. I know bits and pieces of the proofs but it just not looking right to me...please help


Duplicate notification for the same reputation event after editing question title

Step to reproduce  Answer a question; Answer gets accepted or upvoted; Receive notification in the app; Change the title of the question; Notification is duplicated with updated title.  Expected behavior When going into notifcations you should see only one entry for that reputation event. Actual behavior You get two notification entries. In the screen notice the two entries for the same question, the one related to EF. After answering I have changed the name to make it more searchable for future questions and i've noticed it.      App Version: 1.6.1.2 Device: iPhone 6s OS Version: Version 10.1.1 (Build 14B100)


Let's say I have  as a favourite tag and  as an ignored tag.  If somebody tags a question with both   and , it is ignored and does not appear in my list of newest questions.  I would personally like to see this question as it might be interesting / relevant to me.  Would it not make sense that the favourite tag had a higher priority than the ignored tag when there is a conflict?


Photons are massless, but if $m = 0$ and , then $E = 0c^2 = 0$. This would say that photons have no energy, which is not true.  However, given the formula $E = ℎf$, a photon does have energy as $ℎ$ is a non-zero constant and photons with a zero frequency do not exist.  What am I missing here, or does the famous formula not apply to photons?


\includegraphics optional argument not resolved if macro

\documentclass[a4paper,10pt,twoside]{book} \usepackage[demo]{graphicx}  \begin{document}  \newcommand{\scalefactor}{scale = 0.25}  \begin{figure}[!ht]   \centering   %Next line does not work   \includegraphics[\scalefactor]{image}   % The following line works   %\includegraphics[scale = 0.25]{image} \end{figure}  \end{document}   Output:  ! Package keyval Error: scale = 0.25 undefined.   I need to scale a number of images by the same factor, hence the command.   How to solve this and more importantly Why is this only specific to \includegraphics


Where is "the" used? Is there a rule? Why no definite article in "Shops are open late in summer"?

Notice these sentences:   Shops are open late in summer.   Summer is a traditionally viewed as a slow season for games.   At the summer solstice, the days are longest and the nights are shortest.   it's time to start thinking about what 2016's Song of the Summer will be.    In English class, they told us that "the" is used for the things that are known.  One example for this was a phrase like "The man who killed his wife".  So when we are speaking of that man, we know what he did. Somehow we know something more than nothing about him. He's not just every man in the world.     So Now I'm confused about why "the" is not used in the first and second sentences. Can anyone please explain it for me?


I got this problem when I tried to apply material for my sculpt, it just didn't apply, it was just gray, in rendered/material preview mode (see photos). I don't know what the problem is but now it isn't working on normal objects too. I'am using latest Blender version and I have Radeon RX570 graphic card. I never had this problem before. I tried sending sculpt to a friend if he can colour it, and it worked for him.


Is it possible to stop a shutdown command?

Assuming you've just entered the command shutdown -h now (or something equivalent), is there realistically anything you can do (if you're quick enough) to prevent the machine shutting down?


PDF bookmarks don't get proper formatting

In my document, I have two chapter titles with \em commands and --- dashes, which get correctly converted to italics and em-dash in the text. But the PDF bookmarks are not created properly:   \em: if I use syntax \em{text}, bookmark is created with only text (as expected). If I use {\em text}, this entire string is used as-is in PDF bookmark. ---: conversion to em-dash never occurs.   How can I get \em and --- properly in PDF bookmarks? I don't need the bookmark gets styled. Below a code sample and screenshot (in SumatraPDF):  \setupinteraction[state=start] \placebookmarks[chapter, section][chapter, section] \setupinteractionscreen[option=bookmark] \setuptagging[state=start] \starttext \chapter[title={{\em Chapter} --- a note}]  Some paragraph.  \section{{\em A year from monday} --- from John Cage}  Some paragraph.  \chapter[title={\em{Chapter} --- another note}]  Some paragraph.  \section{\em{Silence} --- from John Cage}  Some paragraph.  \stoptext   Screenshot (note bookmarks with --- and \em appearing):


How do you extrude a shape without outer faces and edges?

In Sketchup, if have a shape that I want to cut a section out of, I can use the pencil tool to draw an area and then extrude the area down (using the push / pull tool). The outside edges are removed:     In Blender, I'm trying to do the same thing but it isn't working in the same way. I used the Knife tool to draw the area I want to remove and extrude down, but the outer edges are still remaining:     I haven't yet figured out a way to manipulate the mesh to get the desired result after this extrusion.  Is there a faster / better way to do this in Blender? Is there a tool that behaves similarly to Sketchup's push / pull tool?


How to access the history on the fly in Unix?

For example, if I do a   mkdir thisismyfolder912   I remember there is some easier way to switch to thisismyfolder912 than having to do a  cd thisismyfolder912   What is that way and how does it work? Also, what are the other ways I can use this?


Why 4 is not a primitive root modulo p for any prime p?

I wonder why 4 is not a primitive root for any prime p ?  I've been trying to find an answer with no success so far. Any suggestion would be very helpful, thanks in advance !


Difference between save and saveOrUpdate method hibernate

Normally I had read about save() method generates new identifier for object and only fire INSERT and save it, it does not update it, while saveOrUpdate() method may INSERT or UPDATE record.  But as per my experience, Here I can explains better by sample code,  Suppose there is Class A, and I find record from Table A by  A a = getHibernateTemplate.findById(7);   So now I get a persistent object,   And now I am trying to save record with save method by simply modifying some of fields,  Now I am firing,   getHibernateTemplate.save(a);   So it just update existing record, but as per my knowledge it should create new record.  I may be wrong about certian things, can someone clear about this?


Why do my vertices fade the further I zoom in?

I have tried adjusting clipping value but it doesn't seem to make a difference. I have to constantly go into x-ray mode in order to edit the mesh to see the lines. If I zoom out the lines are there and visible but it's too hard to make changes when that zoomed out to minor details. Any clue?


Why does Flow always occur from Higher Potential to Lower Potential?

This is a sort of a generalized question and not just referring to the flow of current. This includes fluids and many other such entities.  But why does this flow occur. For example if I consider current, then the definition of potential at any point is the work done by external agent in bringing a unit positive charge from infinity to that point. How can we deduce from this definition that the current will flow from higher to lower potential. In fluids, the fluid flows from higher point to lower point. Why so (referring, again to potential)?  Please avoid any analogies in answering the question.


multiple functions in the jquery document.getready doesnt work

If I change the input text of task1, the text box task2 is changed as expected.  But if I change the text box task2, text box task3 is not changed.  What is wrong with my code?  <!DOCTYPE html> <html lang="en">     <head>         <script type="text/javascript"  src="D:\Website\Jquery/jquery-2.1.4.js"></script>         <script type="text/javascript">             $(document).ready(function() {                 $("#tasks1").change(function () {                     alert('testingphase1');                     $("#tasks2").replaceWith('<input type="text" id="tasks2" placeholder="t2">');                 });                 $("#tasks2").change(function () {                     alert('testingphase2');                          $("#tasks3").replaceWith('<input type="text" id="tasks3" placeholder="t3">');                 });             });         </script>     </head>      <body>         <input type="text" id="tasks1" >         <input type="text" id="tasks2" placeholder="taks2">         <input type="text" id="tasks3" placeholder="taks3">     </body> </html>


Is it alright to reapply to a PhD program you got rejected from if you work on your application?

The main weakness in my application was my weak research experience in the field I applied to. Say I got two new writing samples and greatly improved my research experience. Would it be acceptable for me to reapply to a school I got rejected from? I really want to go to that program.


I am looking for a book explaining physics from, say, Galileo and Newton till now; the book should be written using some math, similarly to my physics books when I was at the university (Halliday Resnik). I am searching a book that take care of explaining the true "evolution" of reasoning, discoveries, experiment to prove or disprove something.  I do not like a book that gives definitions without explaining what had happened. I also like to find, on that book, explanations on how actual measurements are taken (how can we measure the speed of light, the mass of celestial bodies, the attributes of electron, and how were the measurements taken in the past - how was possible to measure the speed of light in 1700-1800?).  I am not very interested in recent theories like strings, branes.... so it is OK if these are not discussed.  I like to find a lot of discussions on concept that are related, like for instance the implications on space dimensionalities, ether non-existence, strange facts, missing explanations.


I am currently at this stage of setting up DHCP, and id just like to know what this output in terminal means? I know I have to edit a file but I do not know which one, and I do not know what to put in it. Ultimately I would like to set up a DHCP server.  matt@matt-R580-R590:~$ sudo tail /var/log/syslog Jan  3 17:35:23 matt-R580-R590 dhcpd: Wrote 0 leases to leases file. Jan  3 17:35:23 matt-R580-R590 dhcpd:  Jan  3 17:35:23 matt-R580-R590 dhcpd: No subnet declaration for eth0 (no IPv4 addresses). Jan  3 17:35:23 matt-R580-R590 dhcpd: ** Ignoring requests on eth0.  If this is not what Jan  3 17:35:23 matt-R580-R590 dhcpd:    you want, please write a subnet declaration Jan  3 17:35:23 matt-R580-R590 dhcpd:    in your dhcpd.conf file for the network segment Jan  3 17:35:23 matt-R580-R590 dhcpd:    to which interface eth0 is attached. ** Jan  3 17:35:23 matt-R580-R590 dhcpd:  Jan  3 17:35:23 matt-R580-R590 dhcpd:  Jan  3 17:35:23 matt-R580-R590 dhcpd: Not configured to listen on any interfaces! matt@matt-R580-R590:~$


What is an easy way to export thousands of Adobe Bridge thumbnails for a remote collaborator?

Using Adobe Bridge and/or other Creative Cloud software, how can I export thumbnails with filenames, for a remote collaborator?  I realize there is a tedious way to do this. I am asking for an efficient way to do this. For example, can I export the cache database and have the other party import it?  I have about 60,000 NEF (Nikon RAW) and MOS (Leaf RAW) image files organized into folders and subfolders. Exporting them manually will take an inordinately long time. I need my collaborator to be able to look through all of these and specify file names that they choose.


Changing suspend timer to more than 1 hour

In Ubuntu 13.10, I want to change my suspend timer to go to sleep after 3 hours, but in System Settings I can not do that. I'm wondering is there any way to set it?  I've already tried the instructions in this question:


I never hear "scissor" or "pant" or "jean". It's always "scissors", "pants", and "jeans", respectively. Are they considered plural?


I'm looking for a story or novel in which women (possibly third world) are conscripted to giving birth to missiles (or perhaps some other kind of weapon). Ring any bells?


How to describe the body gesture in this ?    (Sculpture by Anthony Gormley, photo from Teri Gidlof via Pinterest)  Is it natural to say this guy is curling up himself, with his arms holding his knees?  Are there any other terms which can be used to describe him?


Convergence of the series $\sum_{k=1}^{\infty} \left( \frac{1+\cos k}{2+\cos k}\right)^{2k}$. Check my work.

Explore convergence of the series $$\sum_{k=1}^{\infty} \left( \frac{1+\cos k}{2+\cos k}\right)^{2k}$$    Using root test: $\sqrt[k]{a_k} = \left( \frac{1+\cos k}{2+\cos k}\right)^2$ $$\lim_{k \rightarrow \infty} \left( \frac{1+\cos k}{2+\cos k}\right)^2 = \lim_{k \rightarrow \infty} \left(1- \frac{1}{2+\cos k}\right)^2$$  Now as I understand this limit is not really defined but we know it is between $0$ and $\frac{4}{9}$ and therefore is less than $1$. So by root test the series converges. But is this solution correct?


Will increasing the dpi of my image (without re-sampling) hurt print quality?

I'd like to start making prints, but all of my work is set at a resolution of 72. Are there any negative effects to increasing the resolution to 300? I'm very new to this, but from what I've read so far: higher res = nicer looking prints.  I apologize if a similar topic has been posted before, I just wanted to know if there was any pressing reason why I should not be doing this.


"Show that there for an arbitrary positive integer k there exist k consecutive integers none of which is a prime."  How would one go about doing this? It's an exercise in a book on analytic number theory that I am reading. I don't know how I should approach this. Is there a result I could use for this ? Nothing comes to my mind. I've tried for some time now and it's really bugging me that I can't figure it out. A hint or method would be appreciated, thanks.


How to prove $\lim_{n\to\infty}\frac{1}{\sqrt[n]{n!}}=0 $

I need to prove the limit of: $$\lim_{n\to\infty}\frac{1}{\sqrt[n]{n!}}=0 $$  I have tried bounding it by a pairwise bigger sequence but I cannot find one that is suitable. I also cannot figure out an $\epsilon$-proof, since I don't know how to adequately handle the factorial to get a substitution for n such that the convergence criterion is fulfilled.


Should one cite during university exams?

As the title suggests, it's not a usual practice but should one do it? All I know that one can study for an exam and simply write the answers needed in order to succeed, no one tells us to include the names of authors of the ideas we memorized to write (except rarely).


Is $f(x)=\sum_{n=1}^{\infty} \frac{1}{n}\sin\left(\frac{x}{n}\right)$ bounded?

It's relatively simple to prove that this sum converges by using that $|\sin(t)|\leq|t|$ to get that $|f(x)|<\frac{\pi^2 x}{6}$, but this doesn't give boundedness.  I've tried using  and the approximation $\lfloor t \rfloor \approx t$, but the maximum possible error term is linear in $x$ ($2x/\pi$ if I remember correctly), and I've tried to use the Chinese Remainder Theorem to construct values of $x=\frac{\pi}{2} N$ for which the $\sin(x/n)\approx 1$ for small values of $n$, but I haven't been able to get anywhere with that as the behavior of numbers that are close to $n\bmod 4n$ for lots of $n$ is not very nice. My hunch says that there should be values of $x$ for which "the stars align" and the first few terms are close to $1/n$, where "few" is enough for $f(x)$ to get arbitrarily big, but I'm not sure if there's a way to rigorize this via a probabilistic argument.  For completeness, here's a bit of what I've done so far:  Say it were possible for $\sin(x/n)$ to equal $1$ for every $1\leq n\leq K$. Then  $$f(x) = H_K+\sum_{n=K+1}^{\lfloor x\rfloor} \frac{\sin(x/n)}{n} + \sum_{n=\lfloor x\rfloor+1}^{\infty} \frac{\sin(x/n)}{n}.$$  Using for the first sum that $-1\leq \sin(x)$ and for the second sum that $t\sin(1)\leq \sin(t)$ for $0\leq t\leq 1$,  $$f(x)\geq H_K - \left(H_{\lfloor x\rfloor}-H_{K+1}\right)+x\sin(1)\zeta\left(2,\lfloor x\rfloor+1\right),$$  where $\zeta(s,q)$ is the . It shouldn't be too hard to prove that $\zeta(2,q)>1/q$ (although I don't know of a proof offhand), so this implies  $$f(x)\geq H_K - \left(H_{\lfloor x\rfloor}-H_{K+1}\right)+\frac{\sin(1)x}{\lfloor x\rfloor+1}.$$  If $K$ and $x$ are both *large*, this is asymptotically about  $$\ln\left(\frac{K(K+1)}{x}\right)+C$$  for some constant $C$. Thus, if we could make $K$ grow a bit faster than $\sqrt{x}$, we would be able to prove that $f$ is unbounded.  Unfortunately, $\sin(x/n)=1$ for all $1\leq n\leq K$ is not possible for $K\geq 2$ for modular reasons (specifically numbers that are $1\bmod 4$ are not also $2\bmod 8$). So, we would need to find a threshold $\mu$ as well as a $K$ for which $\sin(x/n)>\mu$ for all $1\leq n\leq K$, and then weaken our bounds accordingly. Or, we could try to use a better bound than $-1$ on $\sin$ for the first sum. I'm not really sure.


Display current layout (language code/country flag) in keyboard indicator

Just upgraded from 10.04 to 10.10, and the keyboard indicator applet no longer displays the two-letter country code for the active layout.  This is terrible. Is this the default behaviour? Anyone using two layouts can't tell which language they're in.  I can't seem to find the setting for this, it used to be in the preferences for keyboard layout.  Update 1: In case this wasn't obvious - I have two keyboard layouts - English and Hebrew. I just upgraded form 10.04, where the country code (USA/IL) was displayed, overlaid on the flag.  Now all I get is a vague keyboard icon, and can't find the settings for this.  Update 2: this seems to be a , and is now back in Maverick


Let $(a_n)$ be a Fibonacci sequence , Prove that $a_1+a_3+a_5+\cdots+a_{2n-1} = a_{2n}$  In this question $a_n$ is a Fibonacci sequence, I tried solving it with the PMI , problem arose when i was solving it for $P(n)=k+1$ , I could not make both of the sides equal.


Manipulate a file in code (VB.NET) without executing the file's macros

I have an Excel file that has a bunch of VBA and macro code in it.  When I open the file in Excel I can choose not to 'enable' them - so the values in the fields all stay as they were during the last save.  I need to manipulate the values as they were last saved - so I don't want the macros (which look at the current date and update values accordingly) to run.  When I open it via our dot net code:   Dim oxlRep As Excel.Application Dim oWBRep As Excel.Workbook Dim oSheetRep As Excel.Worksheet Dim oRngRep As Excel.Range oxlRep.Open(path)   the vb code runs - throwing off the values.  I've been looking for a way to open it without macros, or in 'secure' mode where the macros aren't run.  If I simply double click the file and don't choose to enable macros the values are all there as I want them.    Usually we run this code within the month that the files are created, so we haven't seen this problem in the 3 or 4 years that it has been working.  Now I need to go back to some of the old files and run some archival code...    Anyone have a suggestion?


The progressive tense is allowed for happen, e.g. "It is happening now". Thus happen should be a dynamic verb. However, it seems that happen also looks like a stative verb sometimes, e.g. "I happen to be there". I want to make sure if happen is a stative or dynamic verb or both.  Note: This question is very different from the question suggested to be the duplicate because I ask in this question whether happen is a stative or dynamic verb or both, which is not answered in another one.


Compare directories but not content of files

With diff -r  I can do this task, however it takes so long because diff checks file's content. I want something that determine that two files are the same regarding of their size, last modified, etc. But no checking bit by bit the file (for example a video takes sooo long). Is there any other way?


The direct sum $\oplus$ versus the cartesian product $\times$

In the case of abelian groups, I have been treating these two set operations as more or less indistinguishable. In early mathematics courses, one normally defines $A^n := A\times A\times\ldots\times A$; however in, for example, the fundamental theorem of finitely generated abelian groups, we normally write that every such group is isomorphic to one of the form $$ \mathbb{Z}^n \oplus \mathbb{Z}_{r_1} \oplus \cdots \oplus \mathbb{Z}_{r_t}  $$ where $\mathbb{Z}^n$ now means $\mathbb{Z}\oplus\mathbb{Z}\oplus\cdots\oplus\mathbb{Z}$.  From an intuition perspective, and in the sense of sets, is this more or less the same as $\mathbb{Z}\times\mathbb{Z}\times\cdots\times\mathbb{Z}$? (Bear in mind I am normally using these ideas in relation to homology groups.)


What are the dimensions for a standard mug design?

I am wanting to create a nice design in Photoshop and print it on a mug. The printing will be done by a printing company, but I am gonna need to provide the design.   The question is: What are the standard dimensions in pixels for a mug design? If I'm totally misinterpreting the requirements, then what would be the best way to create a mug design in Photoshop?


How to change Iframe height based on its content when Iframe content is on different domain?

I have an Iframe with a content loaded from different domain:

   The content of an Iframe can be of different height.  I have a method resize() executing when iframe loads as follows:  function resize() {     var iFrameID = document.getElementById("frame");     if (iFrameID) {         iFrameID.height = "";         iFrameID.height = iFrameID.contentWindow.document.body.scrollHeight + "px";     } }   When running the page I have an access denied error, I'm assuming because of cross-domain issues.  How can I fix that, so my frame's heights will be changed dynamically based on its content?  Thank's


Let $a$ and $b$ be two integers. Prove that  $$ dm = \left|ab\right| ,$$ where $d = \gcd\left(a,b\right)$ and $m = \operatorname{lcm}\left(a,b\right)$.   So I went about by saying that $a = p_1p_2...p_n$ where each $p_n$ is a prime. Same applies to $b = q_1q_2 ... q_c$. So then $m = (u_1u_2...)(p_1p_2...p_n)$ and $m = (t_1t_2...)(q_1q_2...q_c)$ since $a|m$ and $b|m$. $m$ has a unique factorization, so the primes $(u_1u_2...)(p_1p_2...p_n) = (t_1t_2...)(q_1q_2...q_n)$ and the gcd(a,b) = $(p_1p_2...p_n) \cap (q_1q_2...q_n)$ (I know this is not mathematically correct, so is there a correct way to express this?).   So $dm = |ab| \iff d= \frac{|ab|}{m}$. And by the definition above, $\frac{ab}{(t_1t_2...)b} = \frac{a}{(t_1t_2...)}$. And this is where I get stuck. Is my proof right? Am I going in the right direction?  Thanks   PS. I am trying to do this using only the prime factorization theorem and the definitions of the gcd and the lcm.


How to make an image look like it's been printed

I'm wondering if anyone has any tips, tutorials or templates on how to 'fake' a printed effect. I want to make it look in my portfolio like I have printed business cards and other collateral without doing so.


Why is the Virtualbox not updated in Ubuntu 14.04?

I have installed VirutalBox from the command line using sudo apt-get install virtualbox. I have version 4.3.10 but on the official website the lateste version is 4.3.18. I'v also did the following:     sudo apt-get update sudo apt-get upgrade    but still nothing changed.   I'm using Ubuntu 14.04 64-bit.


Prove that $(ma, mb) = |m|(a, b)\ $ [GCD & LCM Distributive Law]

I'm trying to prove that $(ma, mb) = $|$m$|$(a, b)$ , where $(ma, mb)$ is the greatest common divisor between $ma$ and $mb$. My thoughts: If $(ma, mb) = d$ , then $d$|$ma$ and $d$|$mb$ → $d$|$max + mby$ → $d$|$m(ax+by)$. This implies that $d$|$m$ or $d$|$(ax+by)$. This is the same as  $d$|$m$ or $d$|$a$ and $d$|$b$, so $d$|$m$ or $d$|$(a,b)$. This is the same as $d$|$m|$ or $d|(a,b)$, so $d$|$|m|(a,b)$. I don't know what to do.


How to print special letter such as A and D

How to print the "A" and "D" that looks like the graphs? I tried to use \textit but it does not work?


Import pdf files to google play book application

I want to import my own PDF files to google play book reader and read them using this application. But without any hacking I cannot read not purchased PDFs in google playbook.  I'm not looking for an alternative because they are not good enough (such as ezPDF or Moon+ and ...)


Using Ubuntu at the moment. Not a fan so tried to install Windows 8.1 no luck so far

So basically I bought a new tower for my computer from eBay and it already had Ubuntu installed on it. I'm not a huge fan so I went out and bought Windows 8.1. When I tried to install it, it said "Where would you like to install Windows?" I had 2 partitions to choose from and when I tried both of them, it said they needed to be in the format of NTFS. When I try to format my hard drive from ext4 to NTFS it comes up with this message:  Error unmounting filesystem  Error unmounting /dev/sda1: Command-line `umount  "/dev/sda1"' exited with non-zero exit status 1: umount: /: device is busy.         (In some cases useful info about processes that use          the device is found by lsof(8) or fuser(1))  (udisks-error-quark, 14   How do I stop this and successfully format my hard drive? Please help.


I try to proof that Finite union of closed set is closed. Using this definition of closed set: Closed set it is a set wich contain all its limit points. So i strart from this: We have $E_{1},...., E_{n}$ - closed set. Lets see set $$E = \bigcup_{i} E_{i}$$ let $p \in E_{i}$ is  arbitary limit point. Then we know what exists neighborhood of $p$ which contains at least one point of the set different from p. Because we have union then $p\in E$ and p is limit point for $E$ Next thing, I don't quite know what to do.


what is the most easy to read Algebraic Geometry book?

All:  what is the most easy to read (most accessible) Algebraic Geometry book ?  (If possible, I am looking for an introduction book, maybe for undergraduate, and maybe similar to A Friendly Introduction to Number Theory).


How to use a dataset with only one category of data

I am performing a classification task, to try to detect an object. A picture of the environment is taken, candidates are generated of this possible object using vision algorithms, and once isolated, these candidates will be passed through a CNN for the final decision on whether the object has been detected or not. I am attempting to use transfer learning on InceptionV3 but am having difficulty training it, as I only have one set/class of images. The dilemma is that I only have one class of data and when I pass it through the network, I get a 100% accuracy (because there is nothing to compare it to). How should I overcome this? Should I find more categories online to add to my dataset? What should these categories be? Just to clarify, as an example, I have class "cat". Not "cat" and "dog". Not "cat" and "no cat". Just "cat". That is what my dataset consists of at the moment.


Why should a group of order 33 have an element of order 3

How do I show that $|G|=33$  has an element of order $3$. I could use Cauchy's and say that since $3$ is prime divisor of $33$ there must be a subgroup of order 3. But this problem shows up in Gilligan's book before Cauchy's theorem is introduced. How do I prove this without Cauchy's.   Edit: we also haven't been introduced to Sylow, normal or quotient groups.


So I have the following subspace  $r − s − 2t − u=0$  $−r + 2s + 5t + 2u=0$  $s + 3t + u=0$  $3r + s + 5u=0$  And I need to find the basis. I know that  $r,s,t,u$ are all scalars. I was thinking of decomposing these equations into variables and numbers, but i am not sure.  How would i find the basis ? Could somebody help me?  I was thinkig it might have something to do with the span.


I'm confused about tikz pics. I can freely define them without issue, and even add coordinates inside that will be available by name inheritance like (-A) as for example in \pic (S) at (0,0) {myPic}; \draw (S-A) -- ++(0,0);. This is all documented around p. 255 of the pgf manual.  However I don' understand why it is not possible to give a name to a pic like the one above if no coordinate is defined inside it. By default it would be great if it could behave like a normal node.  MWE:  \documentclass{minimal} \usepackage{tikz}  \tikzset{     myBlock/.pic = {         \node[draw,minimum width=1cm,minimum height=0.5cm] at (0,0) {};     },     myBlockNamed/.pic = {         \node[draw,minimum height=1cm,minimum width=0.5cm] (-m) at (0,0) {};     }, }  \begin{document} \begin{tikzpicture}     \pic () at (0,0) {myBock}; % can't give it a name     \pic (S) at (3,0) {myBlockNamed}; % can give it a name     \draw (S-A) -- ++(2,0); \end{tikzpicture} \end{document}   The underlying point is I'm working on a control blocs library (so that we can stop the chat below with @Alenanno). For example here is the definition of a math operator  \tikzset{     mySum background/.style = {         circle, minimum size=1.5em, fill=white,     },     mySum edge/.style = {         draw=black, circle, minimum size=1.5em, line width=.5pt,     },     pics/bOp/.style = {     code = {       \node [mySum background] {};       \foreach \t [count=\i] in {#1}{         \pgfmathsetmacro{\angle}{\i*90}         \node[anchor=center, font=\tiny] at (\angle:0.45em) {$\t$};       }       \node [mySum edge] {};     },   }, }


How to interpret confusing statements involving either/or/not?

I have a simple problem basically I am unable to understand the meaning of some questions involving or/not, and using comma with and. I have the following questions:-  1.Whats the meaning of, say , X does not play football or cricket.  What we can infer from this. Can we say X does not play both of them? or one of them?  2.How the previous line is different from X does not play either football or cricket.  next is  3.If x does not play both of them, why in books such kind of statements are there instead of neither/nor.  and  4.whats the meaning of M and N, who reads newspaper, are not sitting together.  Here,  Do M and N, both reads newspaper? Please clarify these things to me. I am not a native Englishman so I found it very difficult to understand and as in logical reasoning questions these statements are common to see I face lot of problems. Please also tell me about such more things that can be confusing, may be, provide a link.


What would an observer see if he/she flew toward a clock at relativistic speeds?

If an observer approaches a clock at a significant fraction of the speed of light, would they see the clock's hands moving at a faster or slower than usual rate?  I figure there are two competing effects at play - time dilation and diminishing distance.


Baggage pick up in transit in Istanbul airport

I will be traveling by Atlasglobal and I'll have a connecting flight with IndiGo. Since these are two separate flights booked, Atlasglobal is not ready to book my checked in baggage directly to destination Delhi. As I do not have visa I am not allowed to go out of transit area.   What is the way to collect baggage from belt? Do I need to get a visa?


Query regarding boarding point in Indian railways

I have booked ticket from Secunderabad to Chennai. But now due to changes in mu shedule I want board train at Khammam station.   Can I board that train and claim my berth on my same ticket? Train name: CHARMINAR EXPRESS Class: 3 tire ac


I'm new to Latex and I was wondering if it is possible to look up the documentation of tex packages in the terminal like with man pages? I find myself frequently having to look up stuff online that I think is very basic, like for the titlepage environment. I would ideally love to have a "man" page for this open while working on the document.  Any help is appreciated.


If/Then Field Calculator Return Calculations

After collecting GPS location for road culverts I would like to calculate the $ values for each culvert based on their diameter and length in ArcMap. Existing number fields in the attribute table are Culvert Diameter, Length and the Value field I would like to populate. Unfortunately I have no programming experience so I'm hoping for your help. I adjusted a basic if/then formula I found in this forum and added a multiplication function in the return line. Unfortunately this doesn't work...      def CulvertValue(Diameter):       if Diameter > 0 and Diameter < 14:         return (Length*50)       elif Diameter > 14 and Diameter < 20:         return (Length*100)       else:         return "N/A"   And the result      CulvertValue(!Diameter!)   So let's say the culvert is under 14 inches in diameter and 20 feet long, knowing that a culvert with this diameter costs $50 per foot, the result would be 1,000. I would obviously have to add more elif lines to cover the different price categories. Any thoughts how this could be realized with a Python script?


Logging into the Android App using Google on Android 6.0

Last night I decided to upgrade my phone to Android 6.0 and noticed I am unable to log into the app anymore. I have always used Google as my login for the site and I was logged into the app just yesterday, before upgrading to 6.0.  I double checked that I don't have a password associated with my account by using the "forgot" link and did get back a confirmation email saying that I don't have a password associated with my account and that I can login using my Google account.  Yet this is what my login screen looks like on my 6.0 phone.    And on my 5.1.1 tablet it looks like this.    Looks like a new permission model issue causing the Google login not to show up on Android 6.0, and because I do not have a password associated with my Stack Exchange account, I am unable to login.


Differential Equation Separation of Variables

How do I separate the variables (as I assume will work for this equation) in the following equation:     $yln(x) \frac {dx}{dy} = (\frac {y+1}{x})^{2}$   I am struggling with getting $x$ out of the term $ (\frac {y+1}{x})^{2}$.


Using getHostServices to open a PDF from a WebBrowser

I am fairly new to the JavaFX side of things but so far I have managed to build a Java Web Browser that takes in local html files, however the html files I have also contain links to pdfs. I read that you can use getHostServices() to open up the default pdf application on the system, but I keep getting null pointer exceptions. Everything is imported correctly.  public class AbsorbBrowser extends Region{  public Application a;  final WebView browser = new WebView(); final WebEngine webEngine = browser.getEngine();  public AbsorbBrowser(){      webEngine.load(getClass().getResource("/resources/test.html").toExternalForm());     getChildren().add(browser);      browser.setOnMouseClicked(new EventHandler<MouseEvent>() {          public void handle(MouseEvent event) {              String str = webEngine.getLocation();             String newStr = str.substring(8);              a.getHostServices().showDocument(newStr);             // hostServices.showDocument(file.getAbsolutePath());          }     });   I have it so that when the mouse is clicked that it will assign whatever that location (URL) was to a string, that string would lead to the location:  file:///C:/Users/Me/Desktop/Absorb/bin/resources/test.pdf  So I take a substring and remove the first 8 characters to leave it just with the C:/ directory, then pass that string into the getHostServices().showDocument();  Null Pointer Exception  Exception in thread "JavaFX Application Thread" java.lang.NullPointerException   On the line a.getHostServices().showDocument(newStr);  I tried using java File, but to still no avail. I would appreciate any help or recommendations, thanks.


Programmatically getting a node input slider's max and min

I have already asked this question , but it was actually not answered before it got closed as someone thought it was a duplicate. I now know that I can find a soft_max and soft_min parameter of a NodeSocket, which helps somewhat, but it does not solve it. Why? Because the soft_max and soft_min do not at all correspond to the sliders' max and min. Basically all float value sockets have a soft_max and soft_min of 10000 and -10000, but some of the sliders range between [0,10] or [0, 2] or anything. This range is what I'm interested, and wondering if it is at all possible to find it programmatically. Thank you :D


I see that when I type a double backslash (\\) in a comment on Stack Overflow, it prints only a single \, escaping the \ character. Is escaping this character necessary in the comments section?


How to disable Lock Screen in Windows 10?

I have Windows 10 (Build 14295) Pro. How to disable Lock Screen? I googled it, but there is no solution.   I tried . It does not work for me.


Ya know, there's these [closed] and [on hold] suffix right after the question title in the web version:   See the [duplicate] text? After the question?  Is it possible to add the same thing to the iOS app? Does this text exist in Android app? If no, can the same request be done to the Android app too?


In the answer to the question attached below, I don't quite see how step-3 is derived from step-2, Can anyone explain

Consider two fair $k$-sided dice with the numbers 1 through $k$ on their faces, obtaining values $X_1$ and $X_2$. What is $\mathbb{E}[\max(X_1, X_2)]$ and what is $\mathbb{E}[\min(X_1, X_2)]$.  And the answer to this question as posted in the link above is   HINT: $\min(x_1,x_2) + \max(x_1,x_2) = x_1 + x_2$, so it is enough to evaluate either expected value. Also $\max(x_1,x_2) - \min(x_1,x_2) = \vert x_2-x_1\vert$. Therefore, finding $\mathbb{E}(\vert X_2-X1 \vert)$ allows to determine expectations needed:  $$ \begin{eqnarray}    \mathbb{E}\left( \vert X_2- X_1\vert \right) &=& \sum_{n_1=1}^k \sum_{n_2=1}^k \mathbb{P}(X_1=n_1) \mathbb{P}(X_2=n_2) \vert n_2 - n_1 \vert \\ &=&     2 \sum_{n_2=1}^k \sum_{n_1=1}^{n_2-1} \mathbb{P}(X_1=n_1) \mathbb{P}(X_2=n_2) (n_2 - n_1 ) \\ &=&     2 \sum_{n_2=1}^k \sum_{n_1=1}^{n_2-1} \mathbb{P}(X_1=n_1) \mathbb{P}(X_2=n_2-n_1) n_1   \end{eqnarray} $$  I don't understand how step three in the above answer is derived


My hard drive partition has 323GB of total space and 154 GB of it is used by my files and pagefile.sys, So doing math, 323 GB - 154 GB = 169 GB, BUT the free space on my hard drive is shown as 110 GB which makes a deficit of exactly 59 GB. Can anyone please explain me what is happening here. I am attaching an image which shows the calculated size and the size of my drive as well as the size of all the files in this particular partition.


I am trying to compare two dates which works properly on every device except the iPhone.Its giving wrong alert on iPhone.    function play_time() {     var crntTime;     var today = new Date();     var formattedTime = today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds();     var dd = today.getDate();     var mm = today.getMonth() + 1;     var yyyy = today.getFullYear();     if (dd < 10) {         dd = '0' + dd;     }     if (mm < 10) {         mm = '0' + mm;     }     today = yyyy + '-' + mm + '-' + dd;     var crntDatetime = `${today} ${formattedTime}`;     crntTime = new Date(crntDatetime).getTime();      var check = '2020-08-18 23:14:07';      var gameTime = new Date(check).getTime();      if (crntTime <= gameTime) {         alert('Play');     } else {         alert('Later');     } } <button onClick="play_time();"> show Time </button>


What is safe to exclude for a full system backup?

I'm looking for a list which paths/files are safe to exclude for a full system/home backup.   Considering that I have a list of installed packages.   /home/*/.thumbnails /home/*/.cache /home/*/.mozilla/firefox/*.default/Cache /home/*/.mozilla/firefox/*.default/OfflineCache /home/*/.local/share/Trash /home/*/.gvfs/ /tmp/ /var/tmp/ not real folders but can cause severe problems when 'restoring'   /dev /proc /sys    What about...   /var/ in general? /var/backups/ - can get quite large /var/log/ - does not require much space and can help for later comparison /lost+found/


An additive functor between two categories of left $R$-modules sends zero module to zero module.

The question is to show that an additive functor $F$ between two categories Of left $R$-modules will send the $0$-module to the $0$-module.  How to prove this?


Heisenberg choice of the observables and different outcomes

Somebody could help me to clarify how its possible that different choices of the observable to measure can lead to different outcomes of the observed system state?


Editing a post during review doesn't show an "edit not possible" message

While reviewing First Posts on Super User, I noticed that I couldn't edit this question (see below). Clicking the "edit" link simply does nothing. Editing is not possible for me right now because I have already five suggested edits pending. It used to be the case that the link would've been grayed out (and the reason shown as a popover). , and while I'm not sure it's an improvement, the current implementation needs some fixing at least.  This bug appears regardless of the actual reason that the edit isn't possible; for instance,  is another user experiencing the same bug who couldn't suggest an edit because of an already pending one. Apparently, I'm far from the only one who experiences this issue. As of last Sunday morning,  have been posted networkwide (and are still alive) and  is #16.


When using tmux, I have issues of ghost characters when using the Up and Down arrow keys in Bash. If I press UpArrow a few times and then press DownArrow a few times, then the first few characters of a previous command remain on the Bash line.  For instance, take this clean Bash line:  $   Now I press UpArrow three times:  $ ls /home/dotancohen/Downloads   Now I press DownArrow three times:  $ ls /home/do   I can reproduce the issue with no ~/.tmux.conf file, after exiting and restarting tmux. How should I diagnose this?  Edit: Here is my $PS1:  $ echo $PS1 \[\] - \h():\W$ \[\]   Note that everything from the second backslash up until the last close bracket is green. This function creates the prompt:  PROMPT_COMMAND=$(     cat<<-'EOF'      retval=$?      RED=$(tput setaf 1)     GREEN=$(tput setaf 2)     STOP=$(tput sgr0)      c=0     for i in $retval ${PIPESTATUS[@]}; do ((c += $i)); done      if (($c == 0)); then         PS1="\[$GREEN\] - \h(${WINDOW}):\W$ \[$STOP\]"     else         PS1="\[$RED\] - \h(${WINDOW}):\W$ \[$STOP\]"     fi EOF )


What is magical power in the potter universe and how are these powers compared?

In the most recent movie Fantastic Beasts, Crimes of Grindelwald the minister said to Dumbledore somthing like "Only you can take on Grindlewald, because he's so powerful". That made me somehow wonder. I know there are many types of magical abilities (Foreseeing, Beast transformations, Mind reading, ...) but what makes a wizard more powerful than others? The most powerful wizards mentioned are: Dumbledore, Grindelwald and Voldemort (Maybe the fathers of Hogwarts). I don't recall hearing people discribe Harry as powerful. What makes a wizard more powerful than others? And why can we say that Dumbledore and Grindlewald at their peak were the most powerful?


italic after math equation: how to solve (not solved with $)

I am not an expert with equations on latex. I have wrote these ones within a chapter of a book, but I missed how to write the label on the left with the equation number. Moreover, the text after the equations is italic for a couples of lines and I did not find the way to fix it.  What is wrong?  (Edit with suggestions proposed)  \documentclass[a4paper,11pt,  twoside, openright]{book} \usepackage[T1]{fontenc}                 \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage[a4paper,top=3.5cm,bottom=3cm,left=3cm,right=3cm]{geometry} \usepackage{fancyhdr} \usepackage{setspace} \usepackage{graphicx} \usepackage{caption} \captionsetup{font=small} \usepackage{topfront} \usepackage{emptypage} \usepackage{natbib, authoryear} \graphicspath{figure} \usepackage{longtable} \usepackage{chngcntr} \usepackage{rotating} \usepackage{mathtools} \usepackage{textgreek} \usepackage{hyperref}  \begin{document}  yi \in Y_{i} \sim mathrm{Multinom}(\pi^1_i , \pi^2_i , \pi^3_i )  \pi^k_i = \frac{exp(\eta^k_i)} {1+ \exp(\eta^2i) + exp(\eta^3i)}\hfill     k= 1,...,3  \eta^k_i = ln(\frac{\pi^k_i }{\pi^1_i}) = \beta^k_0 + x_i_1\beta^k_1 +    \sum^11_{j_=_3 } x_i_j\beta^k_j \hfill k= 2,3 \eta^1_i = 0   some text which is italic \end{document}   i have not solved the issue substituing with $\pi$


This is an example from :     I can’t seem to get the hang of this game.   As you may know, 'get the hang of something' means to understand something. But I don't understand the meaning of 'I can't seem to...' here.


I just installed Ubuntu on my Gateway NE56R41u yesterday. Infact, it dual-boots with Windows 8.1 UEFI, but that has nothing to do with my problem. However, when I turn on my computer, I get an error message that displays for about a second. I don't know what it means, though and it displays for less than a second. Tell me, does it mean anything important? How do I fix it? Also, regardless of if it's important or not or if it is fixable, how can I prevent the message from displaying when I turn my computer on? The error is below:  [10.987] info @wl_cfg80211_attach CFG80211 Phy


Classify orbits of conjugating action on $GL_2(\mathbb{C})$

We have a general linear group $GL_{2}(\mathbb{C})$ that acts on the set of $M_2(\mathbb{C})$ set of $2\times 2$ matrices by conjugation.   I want to classify the orbits of its action.  What I know:  $$ Orb_{G}(A) = \left\{ BAB^{-1} : \text{where } B \in GL_2(\mathbb{C})\right\}.$$


Suppose I have a "Type mytype", and if I do "mytype.ToString()", I get "System.Collections.Generic.List`1[Example1.Employee]", how do I get the list item type, which is "Example1.Employee"? Do I have to parse this string to get this list item type? Is there a more elegant way, such as "mytype.ItemType"? Also, why is there a "`1" appendix at the end of "System.Collections.Generic.List`1"? And, why is there a "`2" at the end of "System.Collections.Generic.Dictionary`2"?


Find all irreducible monic polynomials in $\mathbb{Z}/(2)[x]$ with degree equal or less than 5

Find all irreducible monic polynomials in $\mathbb{Z}/(2)[x]$ with degree equal or less than $5$.   This is what I tried:  It's evident that $x,x+1$ are irreducible. Then, use these to find all reducible polynomials of degree 2. There ones that can't be made are irreducible. Then use these to make polynomials of degree 3, the ones that can't be made are irreducible. Repeat until degree 5.  Doing this way takes way too long and I just gave up during when I was about to reach degree 4 polynomials.  My question is: is there any easier way to find these polynomials?  P.S.: this is not exactly homework, but a question which I came across while studying for an exam.


How to Add values to 'config' table and 'key_value' table when creating a new field in an existing table

I need to write a module that need to handle user related details.  I'm able to create the module and add the necessary database changes in 'users_field_data' table. By using db_add_field in hook_install()  db_add_field('users_field_data', 'user_office', array(             'type' => 'varchar',             'length' => 255,             'not null' => FALSE,         ));   But one thing I noticed when installing some other standard module from drupal, when a new field is added to the database it saves some values to 'config' table and 'key_value'table. But when I install the module it only insert the fields to 'users_field_data' table.   Is there a way that I add the values to 'config' table and 'key_value' table when creating a new field in an existing table.


How can I sync my iPad with Ubuntu 12.04.3 LTS?

I have an iPad 3rd Generation, it's called the New iPad, and I don't know how can I sync with my PC. I'm now using Ubuntu 12.04.3 LTS.   Thanks a lot!


modprobe: ERROR: could not insert 'rtl8723be': Exec format error [wifi]

I have restarted my computer after an update, then I have noticed that the wifi signal was very weak. I have decided to download this package https://github.com/lwfinger/rtlwifi_new and reinstall the wifi driver but I have the following error: modprobe: ERROR: could not insert 'rtl8723be': Exec format error  I run the following in the package downloaded:   make sudo make install modinfo -p rtl8723be   I have following result :   swenc:Set to 1 for software crypto (default 0)  (bool) ips:Set to 0 to not use link power save (default 1)  (bool) swlps:Set to 1 to use SW control power save (default 0)  (bool) fwlps:Set to 1 to use FW control power save (default 1)  (bool) msi:Set to 1 to use MSI interrupts mode (default 0)  (bool) debug:Set debug level (0-5) (default 0) (int) disable_watchdog:Set to 1 to disable the watchdog (default 0)  (bool) ant_sel:Set to 1 or 2 to force antenna number (default 0)  (int)   .  sudo modprobe -r rtl8723be  sudo modprobe rtl8723be ant_sel=1   I have following result :  modprobe: ERROR: could not insert 'rtl8723be': Exec format error   I have tried to restart the adapter with the following command:  sudo service networking restart   I'm using ubuntu 17.04 | 4.10.0-33-generic


Can someone tell me how to get the time zone that is set in the WordPress Admin?  For example, if the blog is set to Eastern time, I need this exact string to print out:     US/Eastern   This is for a function that lives in functions.php in my theme.


Creating categories in table based on value ranges?

I am quite new to Arcgis and I am wondering how I can categorize values in a table based on their distance values. For example, I have a table with INPUT_FID and distance values (ignore everything else). I created a new field and I want to categorize each INPUT_FID based on their distances in that new field (A if distance is less than 200, B if distance is more than 200).


Lets say that we have a point charge $q$. Let's draw a Gaussian sphere at a distance $d$ from the charge, as no charge is enclosed inside the sphere the integral $$ \oint_A \vec E \cdot \text d \vec A = 0 $$ vanishes. Hence electric flux at that point is zero. Now I understand that flux through an external point is zero but doesn't that mean that $\vec{E}$ is also $0$, which is wrong. Could someone tell me why this happens and how to use Gauss law?


Why is the speed of light the same for all colors in a vacuum but different depending on the color when light goes through a non-air medium?

I know that red light travels faster in non-air mediums than blue light because of its wavelength, but I'm not understanding why this doesn't happen in a vacuum? This is related to the topic of dispersion and the change of index refractions with wavelength. However, I'm not understanding why this happens. All I know based on educational materials that the index of refraction increases for colors with higher frequencies or lower wavelengths, ie. blue travels much more slowly.


Help me identify this fantasy book about two near-omnipotent wizard run empires

I read the book several years ago (2005-ish?).  I don't think it was new at the time, but it is at least that old.    Here's what I remember:  There are two large empires, ruled by nearly-omnipotent wizards.  Between the two empires, the land is divided into many small countries.  There is a resistance movement against the wizards, but they know they need to take out both at exactly the same time so that the other one doesn't take over everything.  The main character (narrator?) has the ability to recall details perfectly (like photographic memory, but also for sounds, etc).  At one point, he's working with a group of traveling musicians.  He is a young-ish (late teen?) male.        There's one scene where one of the characters has faked his own death to try and attack one of the wizards.  During this scene, the main character (narrator?) is hiding in the attic, eavesdropping.  Eventually in this scene, the one person who knows he's there calls him down to share what he learned by listening.  In the big final battle, there are a bunch of lesser wizards that pretend to help the one wizard to force the other wizard into depleting himself in one giant attack.  They back out at the last minute and let the wizard they were helping get blasted.  There was some other story arch that followed a lady that was trying to work her way into the trust of one of the wizards.  She succeed, but ends up falling in love with him by the end.   Not part of the story, but in the notes from the author (preface?), he mentioned patterning the geopolitics of the world after Italy (during the Renascence or middle ages or something), where there were a bunch of smaller countries/kingdoms/lands that would align themselves with this or that larger power for short-term gain rather than uniting and throwing off all the foreign powers.


I'm trying to understand how oscillators work and am currently working with an RC phase shift oscillator:    $$R_1, R_2, R_3 = 200 \Omega$$  $$C_1, C_2, C_3 = 4.7\text{nF}$$  one of the issues I'm having is that one source states that \$R_{\text{fb}} = 29R\$ for sustained oscillation yet when I set the resistor to \$5.8\text{k}\Omega\$ I get a flat line in nV.   What am I missing out?


My question is simple and possibly stupid, but I wanted to know hypothetically what would happen if two objects start moving away from each other at half the speed of light (0.5c). Is the observed speeds from within the two objects the speed of light.   And if that is the case what happens when two objects move away from each other at the speed of light, is the observed speed from within the two objects 2c? If so doesn't that exceed the perceived speed of light? Does that also imply then that each light particle is possibly moving away from each other at 2c and not just c.  Also, what does a bystander then observe for the 0.5c experiment. Does he observe 0.5c for each object or does he see the two objects depart at the speed of light.   Could all of this imply that the speed of light is simply relative to the point of observation/measurement. Similar to measuring the position of an electron, which in a sense is everywhere and nowhere at the same time and only appears at the time of measurement. Making it less constant and more of a variable.


As a developer it is very common for me to have 2-3 different IDE's open, 10-15 google chrome windows which can hold up to 200 open tabs (I know I get out of hand some times), Photoshop, couple twitter bots for promo, and a few other programs but my system still runs fast and smooth.  I have an i7 processor with 12gb ram.    Now with all my usual stuff running my Physical memory is usually running around 50-60% however over the course of the day or much less even, I will gradually grow to 98%  The highest Memory usage processes will be from Google Chrome, if I sort in the task manager by highest memory usage and end the 1 highest process which will be a google chrome one, my memory usage will jump back down to about 60%.  Also by ending that 1 process, all my Chrome windows will remain open and in use, so it doesn't affect me at all by ending that process.  Based on this research I am assuming that that 1 runaway process is likely the Adobe Flash as I also can say that it gets up to the 98% much faster when I am using flash items like video or music player.  But even without using any of them it will still climb up to that high number eventually.  Has anyone else experienced similar results?


Is there any way to include Python code in a LaTeX file and automatically color its syntax? Is it possible to do syntax coloring with any other language? If yes what packages can I use to do that?


Interchange of rows changes the sign of the determinant

Let $A$ be a square matrix. The determinant of $A$ can be defined as $$\sum_{b\in S_n}a_{1b_1}a_{2b_2}...a_{nb_n}$$  Not breaking this down further, apart from the fact that the first term of this sum is always the product of the terms in the main diagonal of $A$. We take one term from each row and choose the column according to the permutation $b = {1,2,3,...,n}$. If two rows are now interchanged, so does the permutation change its parity from even to odd. Therefore the sign of the determinant is changed as well.  For example, if we swap rows 2 and 3 in a $3 \times 3 $ matrix the first terms $$a_{11}a_{22}a_{33}$$ $$a_{11}a_{32}a_{23}$$ which can be rewritten as $$a_{11}a_{23}a_{32}$$  Which corresponds to an odd permutation. I think my idea is correct, but I'm not sure if its appropriately explained here - thus the example.


Why do utility companies supply at a frequency of either 50/60 Hz?

It just struck me that Utility Companies world-wide supply domestic users at either 50/60Hz. It could have been selected to be 10 Hz, or 100 Hz ... whatever  Was 50/60 chosen at random? Is there some rationale involved (efficiency, easier to construct/control etc) in restricting domestic supply to either 50/60 Hz?  In other words, if I were designing a power system, why would I pick 50/60 Hz instead of some other frequency?


"Select Interior Faces" buggy and unpredictable?

I wrote a tool that outputs a Blender python script that generates a given Minecraft world in Blender using the fewest cubes possible. It's working great, but I'm having terrible difficulty trying to remove interior faces (for optimization reasons).     After I "Remove Doubles" the "Select -> Interior Faces" will select several faces. However, some of them are actually exterior faces and it doesn't even detect a significant number of interior faces.  I don't think there's anything strange going on with my geometry; the vertices are all snapped to the grid, and nothing overlaps.  Is "Select -> Interior Faces" just poorly implemented in Blender? Or is there precursory steps to using it?


Classic $c_r$-inequality in $l_r$ space: $E(|X+Y|^r)\leq c_r[E(|X|^r)+E(|Y|^r)]$

How does one prove:   $$ E(|X+Y|^r)\leq c_r\bigg[E(|X|^r)+E(|Y|^r)\bigg] $$   where $c_r=1$ if $0<r\leq 1$ and $2^{r-1}$ if $r>1$?   This is a classic result whose proof I once knew but have since forgotten. Can someone please explain so I could learn it again? Thank you.


is it possible to install 6.0 marshmellow on a non nexus

im new to this community but is it possible to install android 6.0 on a non-nexus phone with a universal install image  if not please tell


I have a document library with multiple level folder structure, I want to fetch the server relative URL of individual folder by their name. For example: Folder structure in lib like this: Document Library > Folder => subfolder1 => subfolder2 If I pass Name='Folder', it should return /Document Library/Folder If I pass Name='subfolder2', it should return /Document Library/Folder/subfolder1/subfolder2 I tried below restAPI: _api/web/lists/GetByTitle('Documents')/RootFolder?$expand=Folders/Folders&$Filter=Name eq 'subfolder2'  But it returns extra folder details as well. Any extra parameter I can add to my rest URL to filter out extra folder details?


Creating a Grid on a polygon and find number of points in each grid

How can I create a grid on top of a polygon and then insert the points onto the grid?  As far as i know, i am using  guide to created the grid. However, I do not know how to move the grid around the map.   Must I set the SRID?   I am planning to create the grid on the australia and new zealand map.


How to deal with a data-set having all the samples with every feature-point almost similar?


While logged in, I can do the following:  mkdir foo touch foo/bar chmod 400 foo/bar  chmod 500 foo   Then I can open vim (not as root), edit bar, force a write with w!, and the file is modified.  How can I make the operating system disallow any file modification?  UPDATE Mar 02 2017   chmod 500 foo is a red herring: the write permission on a directory has nothing to do with the ability to modify a file's contents--only the ability to create and delete files. chmod 400 foo/bar does in fact prevent the file's contents from being changed. But, it does not prevent a file's permissions from being changed--a file's owner can always change his file's permissions (assuming they can access the file i.e. execute permission on all ancestor directories). In fact, strace(1) reveals that this is what vim (7.4.576 Debian Jessie) is doing--vim calls chmod(2) to temporarily add the write permission for the file's owner, modifies the file, and then calls chmod(2) again to remove the write permission. That is why using chattr +i works--only root can call chattr -i. Theoretically, vim (or any program) could do the same thing with chattr as it does with chmod on an immutable file if run as root.


Relationship between return keyword and finally keyword in c#

i want to find out that the relationship between "return" and "finally" keywords. what is the execution order and what happens when exception occurs and return keyword is called after code block does some stuff, if there is two nested finally blocks as shown below,           try         {             try             {              }             catch (Exception)             {                 //do some stuff                 return;             }             finally             {              }         }         catch (Exception)         {          }         finally         {          }