Redefine underscore to produce upright-shape subscript in math mode

I want to have upright-shape subscripts while in math mode and that by default, i.e. I want to redefine the underscore _  I have found a solution for that here  but it will also overwrite _ when it is not used in math mode and cause problems, for example when including a figure that has an underscore in the name.


Lottery tickets and tax exempt organizations

These might be the same scenario.   I am a pastor.  I find a lottery ticket in the collection plate.  The next day it wins big.  I want to cash in the ticket on behalf of the church.  My church is a tax exempt institution.  Must it pay tax on the winnings? I win the powerball lottery.  I am afraid of so much money and want to donate the winning ticket to my college and wash my hands of the situation.  The college wants to claim the ticket winnings as a tax exempt organization.  Can it do this?


For $n \in \mathbb{N}$, find and prove a formula for $\sum_{i=1}^n \frac{1}{i(i+1)}$, plus related question.

I was fairly easily able to obtain and prove this formula for the sum: $$S(n)=\frac{n}{n+1}$$ by typical means of computing the partial sums, observing the pattern, and proving by induction.   My question is: Is there a more "analytical" means by which to determine this formula?   I ask the same of this question, though let me know if it is too unrelated and should be a separate post:  For $n \in \mathbb{N}$ and $n \geq 2$, find and prove a formula for $\prod_{i=2}^n (1-\frac{1}{i^2})$.


I have a working trigger that I'm starting to build my test class for.  I've done a few lines and ran a test to make sure it's working as it should and everything seems okay, except the trigger itself is 0% coverage.  Can someone help me figure out why?  Trigger:  trigger PartnerLeadAssignment on Lead (before insert) {  List<Lead> leadList = new List<Lead>(); for(Lead l : trigger.new){     leadList.add(l);     if(l.Company == null){         l.Company = l.FirstName + ' ' + l.LastName;           if(l.LeadSource == 'Website' && (l.Lead_Subtype__c == 'Free Resource' || l.Lead_Subtype__c == 'Contact Requested' || l.Lead_Subtype__c == 'Connect with Advisor' || l.Lead_Subtype__c == 'WMC Footer') && l.Referring_Brand_Id__c == '0010H00002SuHKtQAN'){             l.OwnerId = '0050H0000090O6HQAU';              }          if(l.LeadSource == 'Website' && (l.Lead_Subtype__c == 'Free Resource' || l.Lead_Subtype__c == 'Contact Requested' || l.Lead_Subtype__c == 'Connect with Advisor' || l.Lead_Subtype__c == 'WMC Footer') && l.Referring_Brand_Id__c == '0010H00002Vv9gqQAB'){             l.OwnerId = '0050H00000BwRULQA3';              }              if(l.LeadSource == 'Website' && (l.Lead_Subtype__c == 'Free Resource' || l.Lead_Subtype__c == 'Contact Requested' || l.Lead_Subtype__c == 'Connect with Advisor' || l.Lead_Subtype__c == 'WMC Footer') && l.Referring_Brand_Id__c == '0010H00002PZz8zQAD'){             l.OwnerId = '0050H000009LmB3QAK';              }          if(l.LeadSource == 'Website' && (l.Lead_Subtype__c == 'Free Resource' || l.Lead_Subtype__c == 'Contact Requested' || l.Lead_Subtype__c == 'Connect with Advisor' || l.Lead_Subtype__c == 'WMC Footer') && l.Referring_Brand_Id__c == '001i000001siaFLAAY'){             l.OwnerId = '005i0000007xZy2AAE';              }     } }   Test Class:  @isTest public class PartnerLeadAssignmentTest { static testMethod void insertLead(){       List<Lead> leadList = new List<Lead>();     Lead l = New Lead(Company = '', FirstName = 'First', LastName = 'Last', leadSource = 'Website', lead_SubType__c = 'Contact Requested');     leadList.add(l);     if(l.Referring_Brand_Id__c == '0010H00002SuHKtQAN'){          insert l;          l=[Select Company, FirstName, LastName, Referring_Brand_Id__c, LeadSource, OwnerId, RecordTypeId FROM Lead Where Id =:l.Id];         System.assertEquals('0050H0000090O6HQAU', l.OwnerId);         }     if(l.Referring_Brand_Id__c == '0010H00002Vv9gqQAB'){           insert l;          l=[Select Company, FirstName, LastName, Referring_Brand_Id__c, LeadSource, OwnerId, RecordTypeId FROM Lead Where Id =:l.Id];         System.assertEquals('0050H00000BwRULQA3', l.OwnerId);        }        } }   The trigger is much longer than that, but just included a few lines for reference.


do $(x+1)^2$ , $(x+2)^2$ , $(x+3)^2$ span all the polynomials to the power of two or less?

The subject of span and linear independence is still new to me and im unsure if what I did is considered true or not.  what I did was, I put all of the coeffecients of the polynomials in a matrix, and reached this echelon form: \begin{bmatrix}1&2&1\\0&2&3 \\ 0&0&2\end{bmatrix} which means that the polynomials are all independent so I can write all the polynomials up to the power of 2 as a linear combination of these three polynomials.  Is this the way to proof it? are the steps true?  am I supposed to do something with what i got after reaching this matrix?  The second questions is asking if the polynomials: $x^3$, $(x+1)^3$, $(x+2)^3$, $(x+3)^3$ span all the polynomials of power to the power of 3 and less. will it be solved the same way? or im missing something that makes it easier?  any tips or corrections or answers are really appreciated, thanks in advance!


Can the reals be the union of a countable set and a set of lower cardinality?

Without assuming the Axiom of Choice, is the following proposition provable?  If $A$ is countable, and $|A \cup B|=|\mathbb{R}|$, then $|B|=|\mathbb{R}|$.


Why is scaling usually done within the range of -1 and +1 in machine learning?

I observe that in machine learning, scaling is done to make the numeric input fit within the range from -1 to +1. Why not a bigger range like -10 to -10? If smaller range is better, then why not -0.1 to +0.1? Why is this numeric range (-1 to +1) preferred? Is there a mathematical reason to choose this range?


My son and I are playing Borderlands 2 in co op play. Is there a way that he or I can play a separate game on our own that will not affect our on line game? The other day he played for a while on his own and the next time we entered the game together it moved me further ahead in the game than I originally was.


I'd like to take a program P that reads from stdin & writes to stdout, but connect it to nc or whatever such that it reads from a certain port and outputs to another port.  # The reading is easy, here P reads from port 50505 nc -l 50505 | P   How do I get it to write back to say port 60606?


Serious trouble inserting image in MacTex

So I was using the online editor Writelatex and inserting images there is pretty straightforward. However, it's quite slow so I began to use MacTex.  I'm using the \usepackage{graphicx} but I guess the nucleus of my problem is that I don't know how to create the folderpath on mac. My two images are on my desktop. Here is what I've tried:  \graphicspath{{/Users/david villarreal/Desktop}}   and when I have to insert the two images I say  \includegraphics[width=\columnwidth]{B.png} \includegraphics[width=\columnwidth]{A.png}   Can somebody tell me what it is I'm doing wrong?  When I ask the program to tell me what error I have it highlights the following:   Thanks.


McDonald's use "I'm lovin' it." slogan. As we all know that love is a stative verb and young people, too, use stative verbs in the continuous form. Can usage of 'ing' with Stative verbs grammatically correct?


Which tools and technologies are used to build the Stack Exchange Network?

What tools and technologies are used to build the Stack Exchange Network?  See also:


Given $f=\frac{sin^2(x-y)}{|x|+|y|}$ and $f(0,0)=0$  Check for continuity at origin.  I can see that the function takes a value zero when approaching the origin along the x-axis as well as y-axis. But how to prove/disprove it using first principle?


generate all possible 5 digit numbers from format 00000 to 99999 using python

Using the range function or another method in python I would like to calculate all the numbers from 00000 to 99999 where the possible values for a digit in any position could be 0-9 and where the resultant number includes all the leading 0's and must be 5 digits.  So the first number would be 000000 the second 00001 third 00002 to 00009 then 00010 etc.


How to find out how many roots of a polynomial is in each quadrant?

How many roots has $2z^4 -3z^3 + 3z^2 - z + 1 = 0$ in each quadrant?    What I've thought so far is that the polynomial has real coefficients. So we can either have There is one root in each quadrant. There are two roots in the first and fourth quadrant. There are two roots in the second and third quadrant.      However, I am stuck in finding which of these cases hold.


How would I go about determining whether this series converges or diverges?

$$\sum_{n=1}^{\infty} (\ln(2(n+1))- \ln(2n))$$ I was able to plug this into a calculator to determine that the series is divergent. I also graphed the series to observe a decreasing, continuous positive function. Thus, using the integral test seemed like a reasonable choice to determine convergence.  If I didn't have access to a graphing calculator or a calculator at all to solve this problem, how would I go about it? Also, if there are any tools (videos, sites, personal tips and tricks) that can help me determine what test to use to determine convergence/divergence as well as computing the sum, it would be very helpful.


I want to give user a possibility to stop inputing new lines in my String array by entering the word "end". I checked out - it really inputs 'end' before the if statement, but for some reason this doesn't break the while cycle:  Scanner scan = new Scanner(System.in);            String[] str = new String[50];                     int j=0; int f = 0;                            System.out.println("Input 'end' to see your previous input!"); while(f != -1) {   the input goes well, but the if statement doesn't work completely   String choice = scan.nextLine();                 if(choice == "end")                             {                  f = -1;                            }              else              {                  str[j] = choice;                  j++;              }        }


Uniform convergence of bounded functions $f_n$ to $f^*$ implies boundedness of $f^*$

Let $(f_n)$ be a function sequence on $D \subset \mathbb R$ with $f_n \to f^*$ uniform on $D$. Assume $f_n$ bounded for all $n$.   I want to prove the following:  $f^*$ is bounded and  $$  \| f_n \|_\infty \to \| f^* \|_\infty, \quad \sup_{x \in D} f_n(x) \xrightarrow{n\to\infty} \sup_{x \in D} f^*(x)\,. $$    What I have done thus far;  We have that $f_n(x)$ is bounded for each $n \in \mathbb N$. Therefore, for all $n \in \mathbb N$ we can find a $M \in \mathbb R$ (possibly depending on $n$) such that for all $x \in D$ we have $$ |f_n(x)| < M_n\,. $$ As $f_n$ converges uniformly to $f^*$ on $D$, we have $$  \forall_{\epsilon > 0}\exists_{n^* \in \mathbb N}\forall_{n\geq n^*}\forall_{x\in D}: |f_n(x) - f^*(x)| < \epsilon\,. $$  We shall first show that $f^*$ is bounded, therefore we need to prove that there exists an $M^* \in \mathbb R$ such that for all $x \in D$ we have $$  |f^*(x)| < M^*\,. $$  To this end, take $\epsilon = 1$, then for $n \geq n^*$ we have that for all $x \in D$ \begin{align*}  |f_n(x) - f^*(x)| < 1 \iff |f^*(x) - f_n(x)| &< 1\\  \therefore -1 < f^*(x) - f_n(x) &< 1 \\  \therefore -1 + f_n(x) < f^*(x) &< 1 + f_n(x)   \qquad \mbox{but $|f_n(x)| < M_n$, hence} \\  \therefore -1 - M_n < f^*(x) &< 1 + M_n \iff |f^*(x)| < 1 + M_n\,. \end{align*}  Now we have that $f^*$ is bounded by a quantity depending on $n \geq n^*$, which I assume is not enough. At this point I did some research and found  link, which basically says this is sufficient. However, when looking at  link, I would suspect my proof is not enough and we want a value in $\mathbb R$ that bounds $f^*$ independent of any $x$ or $n$.  N.B. I haven't started the second part of the proof yet.


Under what circumstances can one republish a conference paper/presentation?

For conferences that "peer review" and "publish" full papers, when, if ever, can you resubmit essentially unchanged versions for publication in a peer reviewed journal?  In my field, when conference papers appear as book chapters, people often "republish" them as journal articles.  I have just had a talk accepted at a conference which is now (decided post submission) planning on publishing the proceedings as a special issue of a journal. It appears the journal is complete crap with an extremely light peer review process in general, no impact factor, and essentially not indexed. I think this "article" will be worthless, but I am concerned that I will not be able to republish the results in a respectable journal.


In history class one of the TA was referring to some kind of mathematic history and mentioned that no one solved .999..... = 1.0000...... which are both never ending decimals. Then someone yelled 'wrong they're equal' but the TA disagreed.  I just want to know who is right totally curious.  Can someone answer this question? thanks


Importing and executing a local function in python

So I'm trying to complete some of the project Euler challenges in Python3.6 and I've run into this problem:  def divisors(n):     divisors = []     for i in range(2, round(n/2)+1):         if n%i == 0:                 divisors.append(int(n/i))     divisors.append(1)     return sum(divisors)  def checkAmicable(n):     if divisors(divisors(n)) == n:         if divisors(n) != n:             return True     else:         return False  def main():     amicables = []     for i in range(1,20000):         if checkAmicable(i) == True:             if (divisors(i)+i) not in amicables and divisors(i)<10000:                 amicables.append(divisors(i)+i)     print(sum(amicables))  main()   This is my solution to problem 21 (euler21.py), it works and gives the sum of the amicable pairs as asked. I want to be able to import the function "divisors(n)" into another file of code (in this case euler23.py).  From my understanding this should work:  from euler21 import divisors print(divisors(220))   And this should simply print 284, however, when executing it, the entire euler21 code executes and I get the results of that program, plus the 284 at the end, like this:  31626 284   Any suggestions? Could it be due to me using my command line as opposed to the IDE?  TL;DR: imported file executes entire code, not the specifically called function.


I have a quick question. I had 401K from 2 different past employers - Employer A and Employer B. I opened 2 Rollover IRA accounts - one in Brokerage A and another one in Brokerage B in early 2020. I did rollover my old 401k from employer A to Brokerage A and  from employer B to Brokerage B. I read somewhere that I cannot do more than 1 rollover in a year. Is there something I need to worry about even if the rollover is from 2 different employers to 2 different brokerage firms?


Homework question on whether two quotient spaces are homeomorphic

We have two spaces $X=\{(x,1/n):n\neq 0, n\in\mathbb{Z}, x\in\mathbb{R}\}$ and $Y=\{(x,n):n\neq 0, n\in\mathbb{Z}, x\in\mathbb{R}\}$. On both spaces we introduce the equivalent relation $(x,y)\sim (x',y')$ if $x=x'$ and $y=y'$ or $x=x'=0$. That is, all points on the $y$ axis are collapsed to the same point.  We are asked whether $X/\sim$ and $Y/\sim$ are homeomorphic in quotient topologies.  It is easy to show that the original spaces are homeomorphic. However, I don't know how to answer the question about the quotient spaces.   My guess is that they might not be homeomorphic and some problem might occur at the $origin$ but I am not sure.  Any hint would be helpful! Thanks!


Should we answer or comment on a typo question?

According to , questions with a typo or syntax error should be closed. However we still have to address the issue where the OP has made a mistake. Where is the best place to respond to him, in the comments or in an answer?  This question, , is obviously about a syntax error. I left a comment saying where the problem is, and voted to close it as "too localized". However, a user with the close vote privilege chose to give an answer, repeating what was in my comments.  Should we answer the typo question, possibly gaining a few reps, or just leave a comment and close it?


mysql_query doesn't work but db_query does on a simple SELECT query

I'm receiving the following warnings when I use mysql_query() in my modules:  mysql_query(): A link to the server could not be established in ...... on line 6  If I use db_query() instead, it works fine.   The code is a simple SELECT query with no special characters or variables. The actual query is mysql_query("SELECT * FROM custom_nodify WHERE nid = 345");  I should mention that this happens with ANY mysql_query(), not just the one above.  Any suggestions as to why this doesn't work?


Why am I getting an output equals 5? I was expecting 6, because after the "addthenumber(x);" line, the method is called, and what I am thinking is the method performs the calculation and 5 becomes 6. So sysout should print 6, but how is it 5?  public class CodeMomkeyPassingvalue  {     public static void main(String[] args)      {         int x = 5;         addthenumber(x);         System.out.println(x);     }      private static void addthenumber(int number)      {         number = number+1;     } }   output:  5


I am running XP and im looking for a screensaver that does not change the desktop. I.e when the screensaver is active, i want to be able to see my desktop as it is and any changes on the desktop to be visible. Only if i touch the mouse should the login prompt be displayed to inactive the screensave.   For example, i am usually either working on my desktop or laptop. On my desktop i have an applicaiotn running that is showing me stock quotes from the stock exchange. Everytime the screensaver activates i have to touch the mouse to bring the screen back.   What i want to be able to do, is to be working on my laptop and at any time look at the numbers on my desktop without the screensaver interfering. I want the screensaver to be active but its only job is to ask me to enter the password to unlock the screen. I should still be able to see teh stock prices as tehy are changing even while the screensaver is active.   Basicly is it possible to see the desktop while the screensaver is active?   Thanks


How do you line up a pre-existing public domain map with csv coordinate points on QGIS?

I have been struggling with this simple problem all day. I found a Florida map with the counties on Google for GIS. I uploaded the map to QGIS with no problem. However, whenever I try to upload points (both latitude/longitude and x,y coordinates) of areas in Florida, the points do not line up with the map. I have tried different coordinates and I have experimented with the CRS of the maps and I have lined everything up with the same references, but I still have no luck. Has anyone ever tried to do this before?


\addbibresource doesn't work with file contents

I want to cite using the \filecontents command for the books.  But it doesn't recognize the books. It only shows the keyword in bold. It says citation "elch" is undefined      \documentclass[12pt]{article}      \usepackage[ngerman]{babel}     \usepackage[a4paper, text={16.5cm, 25.2cm}, centering]{geometry}     \usepackage[sfdefault]{ClearSans}     \usepackage[utf8]{inputenc}     \setlength{\parskip}{1.2ex}     \setlength{\parindent}{0em}      \usepackage{filecontents}       \begin{filecontents}{ref.bib}     @BOOK{elch,     AUTHOR = "Karall, Benedikt and Schwarz, Markus",     TITLE = "{Eine Studie zur Elchplicht}",     PUBLISHER = "JG-Verlag",     YEAR = 2012}     \end{filecontents}       \usepackage[style=authoryear, backend=biber]{biblatex}     \addbibresource{ref.bib}      \begin{document}      Die exakte Herleitung kann in \parencite{elch} nachgelesen werden.     \end{document}


How to determine distribution from Sleep data min/max/mean values in R?

I want to determine the distribution from the  sleep data which gives only min, max and mean values for sleep clasess in R, in order to estimate quartiles.  Types of sleep waves in the signal in Fig. 1.  I know the thread answer .  Fig. 1 types of possible sleep waves (source Guyton Physiology).     Summary of the descriptive statistics given by the manufacturer given for one measurement session lasting 5-14 hours  dat.m <- structure(list(Vars = structure(c(1L, 3L, 2L), .Label = c("Average ",  "Max     ", "Min     "), class = "factor"), Sleep = c(7, 4, 10 ), Awake = c(12L, 5L, 15L)), .Names = c("Vars", "Sleep", "Awake" ), class = "data.frame", row.names = c(NA, -3L))  > dat.m       Vars Sleep Awake  1 Average      7    12 2 Min          4     5 3 Max         10    15   Current method to estimate the quartiles is manual  #https://stackoverflow.com/a/44043313/54964 quartiles <- data.frame(Vars = c("Q1","Q3"), Sleep = c(6,8),                      Awake = c(9,13))   OS: Debian 8.7 R: 3.4.0 (backports) Related therad:


Recovering Ubuntu 14.04 after installing Windows 7

How can I reuse/access my Ubuntu 14.04 Operating System(OS) to get my important files.  My Hard disk drive(HDD) is partitioned into two.I had previously installed both Windows 7 and Ubuntu 14.04 (on each partition) on my IBM T60 Thinkpad. The Boot-screen that always showed up was that of Ubuntu and I would select either "Ubuntu" or "Windows 7" from there. They(OS) were working very well except Windows 7 had viruses so I had to re-install it. I managed to re-install it but now on booting, it doesn't display any Boot-screen but that of windows 7.   On the hard disk drive(HDD) the partition for Ubuntu is still present.And it occupies all the partition though windows 7 can't show it anywhere.


Prompted by my , what should one do if they find something that might be a bug but aren't sure? Should these be reported? Ignored? Is there somewhere where there is a "tracker for potential bugs"?


I've heard of a automatic compiling system for LaTeX which works as follows: I simply upload a .tex code to a website and this system automatically compiles it into .pdf. How to find it?


Continued Fractional representation of irrational numbers

I know that any rational number can be expressed as a continued fraction, but what about irrational numbers? For example, what is the continued fractional representation of Pi, or e for that matter? Can all real numbers be expressed as continued fractions? For example, can the following number be expressed as a continued fraction?  0.1234567891011121314...


Last fall I tried my hand at making a homemade hot sauce. Essentially: roast peppers, blend with vinegar, garlic, salt and other spices, put in jar for three weeks, strain and you have hot sauce.   The sauce was great, but after about a week of sitting in a jar in my fridge it separated and became rather unsightly. Of course, after shaking it up it returned to normal. Is there a way to keep a sauce like this from separating?  Thanks!


zsh, modularity,multiple .zsh files and oh-my-zsh

I use/enjoy zsh and have used oh-my-zsh in couple. While it's all nice and cool, I do get irritated that I have to constantly update the oh-my-zsh script every 15 days/month .   Now I have put zsh as a prompt on another machine. Now the good thing about my oh-my-zsh is that instead of putting everything in .zshrc which when you install .zsh does, it does it in multiple directories with .zsh extension.   While I do not want to go that whole hog, is there a way I can put multiple *.zsh files under say ~/.zsh/ and strive to have a similar working environment.   Can this work or am I missing something ?   Running zsh on debian 64-bit.   Update - There are only two files which can be in my zsh installation -  think-debian% pwd /home/shirish  think-debian% ls .z .zcompdump  .zshrc   Any ideas ?


I just  that stars have metals in their cores that could theoretically be harvested by injecting enough mass to cause a supernova.  Say someone wanted to do this to our Sun.  How would you calculate (roughly) the amount of mass you would need to inject into the Sun to make it explode?


Salesforce.com >> Using a validation rule, how to allow specific user to create a new record on Account and restrict other user?

Salesforce.com >> Using a validation rule, how to allow specific users to create a new record on Account and restrict other users? In my org, a validation rule is already present to restrict the user from creating the new account except for a few users who are allowed to create a new account. Such authorized users can do this with a permission set that is assigned to their user configuration. Also, validation is already present which restricts all other users to enter a new account/data. In this validation, user ids are hard-coded as authorized users are not supposed to encounter this validation which working on the account. Is there any way to avoid hard-coding of user ids and keep the application working as expected?


how to patch bash vulnerability (shellshock) bug on RHEL?

We have over 10000 servers to patch for bash vulnerability (shellshock) bug. Now my question is what is the command to patch this bug ? And how we can check whether the patch has been installed and the bug has been fixed ?


I want to use the catchfile package to import the data of nodes from external file ver.dat as following:  \documentclass[tikz]{standalone} \usepackage{catchfile}  \CatchFileDef{\myver}{ver.dat}{}  \begin{document} \begin{tikzpicture}   \foreach [count=\i] \coord in {\myver}{      \node (p\i) at \coord {\i};   } \end{tikzpicture} \end{document}   where the file ver.dat is (1,0),(0,1).  But the above code doesn't work, what's wrong?


Selecting features that do NOT intersect in ArcGIS Desktop?

I used the "create spatially balanced points" in Geostatistical Analyst in ArcGIS 10 to generate a large set of points with equal inclusion probability but a "spatially balanced" dispersal. I then buffered these using different buffer settings, with the idea of explicitly testing the influence of sampling unit size on population estimates (in my case, tree cover) using a fixed area sampled. This latter detail is key - I sum of the area for the sum of the selection of buffered points to be the same between comparisons. A toy example: what's the difference sampling 10 polygons 1 ha each in area (10 ha total) versus 100 polygons, each measuring 0.1 ha (again, 10 ha total). The point layer created by the tool qualitatively has the desired dispersion, but when you start buffering points, some start to overlap, reducing the total area (plus violating any possibility of independence between samples).   What I'm looking to for is an efficient way to find features that DO NOT intersect. I saw a post asking a similar question for PostGIS, but was looking for a way to approach the question using ArcGIS.


How to get CPU and RAM usage from windows machine using python?

In my windows machine, I have created 3 virtual machine and I want to get the CPU and RAM usage of each virtual machine using Python.  How can I achieve this?


How to copy YouTube playlist from one account to another?

NOTE: This is a duplicate of this  and I made it because my account is new I couldn't neither comment nor answer the question so I decided to ask it and answer it myself. If you're a mod/admin try moving my answer to the previous question if you can.


Does java 8 streams reuse itself when processed again on the same data and task?

I was trying the code to check the time taken by stream() and parallelStream() for the same operation.   Code 1  List <String> list = new ArrayList < String > ();  for (int i = 1; i <= 30000; i++) list.add("a"); for (int i = 1; i <= 20000; i++) list.add("b"); for (int i = 1; i <= 10000; i++) list.add("c");  //part 1 long start = System.currentTimeMillis(); Map <String, Long> countListSequence = list.stream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end = System.currentTimeMillis();  System.out.println("Time taken in by stream() " + (end - start) + " millisec data " + countListSequence);  //part 2 long start1 = System.currentTimeMillis(); Map <String, Long> countListparallel = list.parallelStream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end1 = System.currentTimeMillis();  System.out.println("Time taken by parallelStream() " + (end1 - start1) + " millisec data " + countListparallel);   Output 1  Time taken in by stream() 109 millisec data {a=30000, b=20000, c=10000} Time taken by parallelStream() 16 millisec data {a=30000, b=20000, c=10000}   But if I changed the order first use parallelStream() then stream() like  Code 2  //part 1 long start1 = System.currentTimeMillis(); Map <String, Long> countListparallel = list.parallelStream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end1 = System.currentTimeMillis();  System.out.println("Time taken by parallelStream() " + (end1 - start1) + " millisec data " + countListparallel);  //part 2 long start = System.currentTimeMillis(); Map <String, Long> countListSequence = list.stream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end = System.currentTimeMillis();  System.out.println("Time taken in by stream() " + (end - start) + " millisec data " + countListSequence);   Output 2  Time taken by parallelStream() 109 millisec data {a=30000, b=20000, c=10000} Time taken in by stream() 15 millisec data {a=30000, b=20000, c=10000}   My question is that why the second part stream() in Code 2   is taking less time then parallelStream() showing different behavior from Code 1?  Not only in the case of stream() and parallelStream() I also tried the same situation with stream() and stream() .I got the same situation with that also, second stream is taking less than first stream.  Code 3  //part 1 long start1 = System.currentTimeMillis(); Map <String, Long> countListparallel = list.stream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end1 = System.currentTimeMillis();  System.out.println("Time taken by stream() 1 " + (end1 - start1) + " millisec data " + countListparallel);   //part 2     long start = System.currentTimeMillis(); Map <String, Long> countListSequence = list.stream()     .collect(Collectors.groupingBy(e -> e, Collectors.counting())); long end = System.currentTimeMillis();  System.out.println("Time taken in by stream() " + (end - start) + " millisec data " + countListSequence);   Output 3  Time taken by stream() 1 107 millisec data {a=30000, b=20000, c=10000} Time taken in by stream() 14 millisec data {a=30000, b=20000, c=10000}   Second print showed less time then first.So does stream calculated data reuse itself if I would believe that how could it be possible because the object created countListSequence and countListparallel are different.I am confused here how the second part in each code sample take less time then first part. Am I miising something about streams here?  Thanks


A-roving, a-walking, a-verb participle: what is this called?

Is there a name for the archaic form of a-verb participle, as in a-walking? It appears in poetry and songs, for example,  As I was a-walking down Paradise Street...   Time is the stream I go a-fishing in.


Installing NVIDIA drivers appears to be inconsistent

Following the instructions , I am attempting to install some specific NVIDIA drivers on Ubuntu 18.04. I am doing this as the first thing after a fresh installation of Ubuntu, such that there are no NVIDIA drivers already installed.  The instructions say to run:  sudo apt-get install --no-install-recommends nvidia-driver-418   After doing this, I run apt list --installed | grep nvidia to see what NVIDIA packages it has installed. It prints out 17 package names, including nvidia-driver-418 and nvidia-driver-430.  Then, I run nvidia-smi, and this print out Driver Version: 430.26.  I have also looked at Ubuntu Software -> Additional Drivers, and the checked radio button is for Using NVIDIA metapackage from nvidia-driver-430 (proprietary, tested). Below this is an unchecked radio button for Using NVIDIA driver metapackage from nvidia-driver-410 (open source).  This doesn't seem very consistent to me... My questions are:   Why does installing nvidia-driver-418 actually install both nvidia-driver-418 and nvidia-driver-430? Given that 430.26 is the driver being used by my system (presumably from the nvidia-driver-430 package), how can I tell my system to actually use the 418 version of the driver? It seems that I could use Ubuntu Software -> Additional Drivers, but this lists version 410, not version 418. And I haven't even installed version 410... What's going on?


How do I install an Nvidia driver in VirtualBox?

I am trying to install the NVIDIA driver on in an Ubuntu guest running on a Windows host (to install the GPU-supported tensorflow). Is it possible to do this?  I am using NVIDIA GeForce 849M.  I downloaded the driver from NVIDIA and installed it with:  sudo service lightdm stop sudo init 3 sudo sh NVIDIA-Linux-x86_64-364.69.run   Then I get and warning like the following:     WARNING: You do not appear to have an NVIDIA GPU supported by the   384.69 NVIDIA Linux graphics driver installed in this system.   For further details, please see the appendix SUPPORTED NVIDIA GRAPHICS   CHIPS in the README available on the Linux driver download page at   www.nvidia.com.      -> License accepted.      -> Installing NVIDIA driver version 384.69.      -> Running distribution scripts    executing: '/usr/lib/nvidia/pre-install'...      -> done.      -> The distribution-provided pre-install script failed!  Are you sure you want to continue? (Answer: Abort installation)      ERROR: Installation has failed.  Please see the file   '/var/log/nvidia-installer.log' for details.  You may find suggestions   on fixing installation problems in the README available on the Linux   driver download page at www.nvidia.com.


Do by ref parameters guarantee that the variable stays at its current position in memory?

, but what exactly happens with the objects passed by ref? Is it guaranteed that the objects stay at their current position in memory while the reference is being used?  Does it make a difference whether the variables are locals or not?  I'm mostly interested with what happens in memory.  A bit of background information: I have written a simple test program that stores the memory address of objects passed by ref and noticed how C# likes to move objects around in memory. But what I think is odd was that the objects being used were locals of a function. This automatically makes me think that the object's reference can't move in memory because it is on the stack. But clearly I'm missing something. What kind of memory was I receiving when using the ref?


Salesforce design to support both Workflow field update and Trigger

I am having a use case where I've to do both Trigger and workflow field update.  There are 2 objects. One is Case and other one is Case_child__c and Case is master and other is child.  I'm having an issue, where a Case Trigger is calling a method caseAssistanceMethod. There we are inserting new Case_child__c record based on some conditions. (Business Logic)  trigger Case_afterUpdate on Case (after update) {      CaseTriggerUtils.caseAssistanceMethod(Trigger.new, Trigger.oldMap);   }   Public class CaseTriggerUtils {      public static void caseAssistanceMethod(List<Case> newCaseList, Map<Id, Case> oldCaseMap){         // Here we are writting our business logic.     { }   But, here is my question, above logic is working fine unless there is no workflow field update. If we have any workflow which is updating any Case field, then After_Update Trigger on Case is getting called again.  Because of this I am getting duplicate Case_child__c records. Where I 'm supposed to get only single Case_child__c record.  So, is there any design where we can do both Trigger call and workflow field update on Case, without creating Duplicate Child Record.


Currently I have a script that can run only in a single folder.   #!/bin/bash for file in ls -1 *.jpg|sort -t . -n -k 3 do   echo "compute ./scripName $file"   ./scriptName $file done    Question: I have a several folders containing *.jpg images. I need a script that can over all images of all folders.


Many-worlds interpretation (MWI) and conservation of energy

I am not an expert of  (MWI), and what I say may be stated incorrectly. In that case i welcome corrections. If the MWI is true and it explains quantum theory and it splits for any possible outcome, is there a global amount of energy/mass that is conserved?


Is research experience in a different field relevant for PhD application?

I am a economics major undergraduate student who will apply for grad schools in the coming semester. I think I have quite a strong research experience in mathematical statistics (asymptotic statistics to be specific), but, unfortunately, not much in economics itself. So I am curious if economics departments in graduate schools will care about my research experience in statistics?  Maybe a broader question is if grad schools care about applicants' research experience in a different (maybe even unrelated) field at all? I guess in my case statistics and economics are still quite correlated, but what about other more distant combinations of target departments and previous research experience?


Why isn't Tony Stark injured or killed while he repairing Helicarrier rotor?

When he moves in a circular motion very fast, there are large G-Forces acting on his body, even while he is wearing his suit.  This is similar to being in a G-Force simulator.                                  or like when you are in car that is turning left very fast.  Does his suit have ability to protect him from this G-Force? If it does, how does it work ?


Proving $\lVert x \rVert_3$ is smaller than euclidean norm

Is there a simple way to show that $\lVert x \rVert_3\leqslant \lVert x \rVert_2$ for vectors in $\mathbb{R}^2$? I've used the result in another problem but can't figure out where to get it from.


How do I put keywords after abstract in amsart?

I'm using amsart and want to place keywords after abstract but amsart places them in the footnote. Does anyone know how Ι can override this?  An example of the code I've been using:  \documentclass[12pt, reqno]{amsart} \usepackage{ amsthm, amscd, amsfonts, amssymb, graphicx,tikz, color, environ} \usepackage{hyperref} \begin{document}  \title \address \date \keywords \maketitle  \begin{abstract}  \end{abstract}  \end{document}


Why AbstractCollection does not implement equals()?

Did you know that :  Map<Object,Object> m1 = new HashMap<Object, Object>(); Map<Object,Object> m2 = new HashMap<Object, Object>(); System.out.println("m1.equals(m2) = "+m1.equals(m2)); System.out.println("m1.keySet().equals(m2.keySet()) = "             +m1.keySet().equals(m2.keySet())); System.out.println("m1.entrySet().equals(m2.entrySet()) = "             +m1.entrySet().equals(m2.entrySet())); System.out.println("m1.values().equals(m2.values()) = "             +m1.values().equals(m2.values()));   would output :  m1.equals(m2) = true m1.keySet().equals(m2.keySet()) = true m1.entrySet().equals(m2.entrySet()) = true m1.values().equals(m2.values()) = false   This is caused by the fact that AbstractCollection (which HashMap$Values inherits from) does not overrides #equals().  Do you have an idea why this is so ?


Proving a triangle with different edge colors exists in a graph.

This is again some homework translated (hopefully not too badly) from my book  The graph $K_{n}$ is colored using $n$ different colors, in a way that each color is used at least once. Prove that there exists a triangle with its edges colored in different colors.


Singular possessive apostrophe for name ending in "s"

Creating some copy and want to make sure singular possessive name is correct...  If I have a name of an animal, Jaws, would correct grammar be, Jaws' Laws?


So I have matrices $A \in \mathbb{R}^{m\times n}$ and $B \in \mathbb{R}^{n\times k}$, I should proof these two inequalities: $rank(AB) \leq \max(rank(A),rank(B))$ and $rank(AB) \leq \min(rank(A),rank(B))$.   So I understand that $A: \mathbb{R}^{m} \rightarrow \mathbb{R}^{n}$ $\Rightarrow$ $\max(rank(A)) \leq \max(\dim(Im(A))) = n$ and $B: \mathbb{R}^{n} \rightarrow \mathbb{R}^{k}$ $\Rightarrow$ $\max(rank(B)) \leq \max(\dim(Im(B))) = k$ and $\min(rank(A)) = \min(rank(B)) = \min (rank(AB)) = 0$.  But what after?


Is it possible (and also meaningful) to do two PhDs?

During my PhD I have developed two different research projects in parallel. This was not planned from the beginning, it just happened this way. I am sure each of these could be presented as a PhD and I am thinking on the possibility of presenting both, one after the other one. Would that make sense?  I had a quick talk with my Professor although I didn't ask him about this option because I had the fear he would find it a bit arrogant. So first of all, I wanted to get to know if it is meaningful.   Thanks in advance


Button created after ajax call not working while event is triggered

I have the following code in html:

         Name	         Parent	         Priority	         Action

         test	         null	         0	                      <button value="3" type="button" class="btn btn-danger btn-sm"></button>

         Lifestyle	         null	         1	                      <button value="2" type="button" class="btn btn-danger btn-sm"></button>

         Travel	         null	         1	                      <button value="1" type="button" class="btn btn-danger btn-sm"></button>

     And I have the following code in the footer:  $("#check tr td button").click(function () {     alert('here'); });   But the event does not seems to work. Why is my code not working? The data in table are created after a ajax call. Is it because of ajax?


If $\lim_{n \to \infty} \sum^n_{k =0} \frac{nC_k}{n^k(k+3)} =ae+b$

Problem :   If $$\lim_{n \to \infty} \sum^n_{k =0} \frac{nC_k}{n^k(k+3)} =ae+b$$  then find the value of a-b.  Please suggest how to solve such problem in whicl summation and limits both are there. Thanks.


Why does "ls | wc -l" show the correct number of files in current directory?

Trying to count number of files in current directory, I found ls -1 | wc -l, which means: send the list of files (where every filename is printed in a new line) to the input of wc, where -l will count the number of lines on input. This makes sense.  I decided to try simply ls | wc -l and was very surprised about it also gives me a correct number of files. I wonder why this happens, because ls command with no options prints the filenames on a single line.


We know that Yui was saved in Kirito's NervGear's local memory in the first season of Sword Art Online but in in the second season when Kirito is in Gun Gale Online, when everyone is watching Battle of Bullets Yui is there with everyone else watching it in ALO. she also talks to Asuna on her phone when she heads off to the hospital and in Agil's bar when Kirito sets up the cameras for her.  in all of these cases Kirito isn't using his NervGear and i would suspect it is turned off. so where is Yui now stored? and how is she able to go from this place to ALO, Asuna's Mobile and the cameras in Agil's bar?


can't paste the project file into the htdocs on ubuntu

for command   sudo usermod  -R root.xamppusers /opt/lampp/htdocs   ....it shows  usermod: invalid chroot path 'root.xamppusers'


check ip address of a linux server to upload the file

I am working on a linux server remotely. Are there any command that can allow me to figure out the IP address of this linux server, so that I can ftp some files to this server.


Help! I'm losing my mind in this process... My 3 year old boy wants to wear pull ups and stays dry most of the time. And tells me, I'm all dry! But, When he sits in the potty... Nothing! I don't think he is connecting the dots and really understands what is supposed to happen... Is he NOT ready? Should I go back to diapers? I feel like I'm wasting his and my time!!! How do I help him "get it"???


Why can't I see my favorite locations anymore when saving a file?

Here is a picture of my finder  On the left, there are my favorites which is very handy for quickly accessing important folders. I used to have access to the favorites when saving a file or when searching a file to send by email. Problem Recently and with no apparent reason, I can't see the favorites anymore when trying to save a file or when trying to select a file to send attached to an email. (I can still see the favorites when navigating with the Finder). Here is what it looks like when trying to save a Microsofot Word document  Here is what it looks like when trying to select a file to attach on an email (via GMail)  Question How can I get my favorites back? OS I am on a desktop running on Mac OSX 10.11.3


what's the special meaning of $ as argv in linux

I wrote a simple c application and test on centos 6.5, the code as below  int main(int argc, char *argv[]) {     fprintf(stderr, "%s\n", argv[1]);     return 0; }   when I run the app with ./test $, then the print value is $, but if I run with ./test $$, the print value changed to 119688, is any special meaning of $ in linux, I found it works correctly on windows.


Formula for molar specific heat capacity in polytropic process

I found this formula for a , defined by $PV^n = {\rm constant}$, in a book: $$C = \frac R{\gamma-1} + \frac R{1-n} $$ where $C$ is  and $\gamma$ is . I do not know how it was derived, can someone guide me?


How to determine the distribution of Ubuntu

I want to launch an EC2 instance on AWS. I want to install Ubuntu Xenial distribution. How do I know which one of these is Xenial?  I see a lot of options like:   Ubuntu Server 18.04 LTS (HVM), SSD Volume Type - ami-0b76c3b150c6b1423 Ubuntu Server 14.04 LTS (HVM), SSD Volume Type - ami-001dae151248753a2 Deep Learning AMI (Ubuntu) Version 23.0 - ami-0726ab58f406b644f Deep Learning Base AMI (Ubuntu) Version 18.0 - ami-00c2ec90e50ed2f33 Ubuntu Server 16.04 LTS (HVM) with SQL Server 2017 Standard - ami-f13ff693 Ubuntu Server 14.04 LTS (HVM), SSD Volume Type - ami-0d21bd76bdbb39f53   Update  The reason I want Xenial is that Galera cluster is already built for xenial:


How do you distinguish between magic effects that bypass immunity and those that don't?

This question was triggered by .  Basically, it goes like this: If you have a weapon with a certain magical effect, let's say the minor property unbreakable (can not be broken, requires special means) or temperate (no harm in temperatures between -20 to 120 F), it can bypass the immunity of something like a Werewolf because it is magical instead of mundane. This goes for any minor property because those properties are under the Magic Items portion of the DMG on pg.143.  How does this differ from a pair of gauntlets with the exact same effect being used as an improvised weapon (emphasis added for clarity) from dealing damage in the same manner to the same Werewolf? Or something that's clearly not a weapon like a Shield of Missile Snaring being used to bash an opponent?


What does eno mean in network interface name 'eno16777736' for CentOS 7 or RHEL 7?

Under consistent network device naming scheme, what does 'eno' stand for in network interface name eno16777736 for CentOS 7 or RHEL 7?


Prove for every x,y of the Positive Integers such that x|y and y|x implies x=y?

Could someone walk me through this problem from my Discrete Mathematics textbook? It states: Prove that $\forall x, \forall y \in Z^+$ such that $x|y$ and $y|x$ implies $x=y$, or in English for every x,y in the Positive Integers such that x divides y and y divides x, implies x=y.  Proofs are not my strong-suit by any means, my go to usually being to attempt a proof by Contradiction. However, for this one I'm just stuck with the statement being true because, as my instructor likes to say, "Clearly Obvious"? I mean, if x=y then if x=4 and y=4, then 4/4 = 1 meaning both ways they divide the other and are equal?   Can someone explain this to me?


What is a fixed effect in a mixed model compared to a fixed effect model for panel data?

I am confused about the expression "fixed effect" in the context of mixed models. I am more familiar with the terms like "fixed effects" and "random effects" in context of econometrics and the analysis of panel data.  The understanding of "random effects" seems similar in both disciplines and the "random effects model" in econometrics is equivalent to a "mixed model with random intercept". See for example:   But what is about the "fixed effect". In econometrics, with the help of fixed effects e.g. all time invariant effects will be absorbed. Or in other words, a dummy variable for each individual is introduced.  But, what is "fixed effect" in context of mixed models? In simple words? Hereby, I mean more the intuition and not the mathematically way.  It is not the same as a fixed effect in econometrics. That is what I understand, but I have no clue what it is instead.  EDIT:  Meanwhile I found this explanation in context of mixed models:  "The fixed effects are analogous to standard regression coefficients and are estimated directly."  This means to me, that a fixed effect in mixed models is not the same as fixed effects in econometrics. Or in other words: Fixed effects are the variables that are not declared as random effects (--> standard regression coefficients as in linear regression).  Source (slide 2):


could you possibly install a malicious program using apt-get?

While installing various programs, I get asked to download some packages that are required for it to work. Some of them are well known applications, where the read-me document is trustworthy whereas some other lesser known programs are the ones where I guess I need to be careful.  So, I'm trying to install a game known as Tennis Elbow, where the read me doc says:     On Ubuntu 14.10 64bit, the following instructions have been reported to work:  sudo apt-get install libcurl3:i386 sudo apt-get install libvorbisfile3:i386    So, how can we know if the files I download are safe or not?  I know this seems like more than one question, but I basically need this game to work, and so I just need know if I it is safe to install the packages mentioned or not.


How to respond to "How much funding will you bring?" as an interview question for a faculty job?

What are the possible answers for such interview question assuming a new graduate with no funds! How much funding you will bring to the department?


Say I'm having a conversation and somebody besides me asks "you didn't go to the movie", so usually I would say "no" even though they are correct.  Is there a name for this? Any more information?  I'm in the USA if that helps


QGIS area calculation differs when on the fly CRS transformation enabled

When I open QGIS, add the layer, and calculate the areas of the shapefile via field calculator I get a different area than when I open QGIS and check "Enable on the fly CRS transformation" and calculate the area. This is despite making sure that the project and the layer have the same Coordinate system (same EPSG number). What am I doing wrong?   I have a shapefile with area calculations made with ArcGIS (not be me, the data was handed to me and I have no clue for which CRS the area was calculated with ArcGIS). The shapefile layer CRS is EPSG: 21781 (Switzerland). In QGIS, if I do not change the OTF settings and leave the project CRS as EPSG:4326 (WGS84) I get the same value as the ArcGIS area value. However, if I change the OTF before adding the layer to EPSG: 21781 I get different area values. As I understand this suggests that ArcGIS Area was calculated with the CRS EPSG: 4326.  First workflow:   open QGIS  project CRS: EPSG 4326  add layer  project CRS adapts automatically and is EPSG 21781 now  calculate $area with field calculator    Second workflow:   open QGIS  project CRS: EPSG 4326  Turn on OTF, set project CRS to EPSG 21781  add layer  calculate $area with field calculator    Step 5 of the first and second workflow DO NOT produce the same area.


When searching a keyword like [botframework] on search box, if the spelling of the keyword is not correct like [botframewrok] (which o and r are misplaced in wrok) the search result would be empty:    Now, my suggestion is, if the specified tag is not in the tag space, try to map the tag into the near tag and show the result of the auto-corrected tag. It might be this mapping be using the minimum Levenshtein distance.


Is it possible to make a two way connection between two cells

How can I allow the user of my Excel sheet to enter data in either of two cells and have both cells updated?   I have cell A4 in Sheet 1.  I have cell B7 in Sheet 2.   If the user types 100% in cell A4 in Sheet 1, both cells A4 and B7 should say 100%. If the user types 80% in cell B7 in Sheet 2, both cells A4 and B7 should say 80%.  I am using Excel 2013 but have access to 2016.


SQL Reporting Services (SSRS) - Blocked process on ReportServer, SP CheckSessionLock

We frequently see blocking on our SSRS box which houses both front-end Report Manager ReportingService and the SQL database engine with ReportServer & ReportServerTempDB Catalog databases  Blocking session:     Database name: ReportServer     Application name: Report Server     Host name: SSRS01     OS User name: SYSTEM     Database User name: NT AUTHORITY\SYSTEM     First 2KB of SQL: CREATE PROCEDURE [dbo].[CheckSessionLock] @SessionID as varchar(32), @LockVersion  int OUTPUT AS DECLARE @Selected nvarchar(32) SELECT @Selected=SessionID, @LockVersion = LockVersion FROM [ReportServerTempDB].dbo.SessionLock WITH (ROWLOCK) WHERE SessionID = @SessionID  Blocked session:     Database name: ReportServer     Application name: Report Server     Host name: SSRS01     OS User name: SYSTEM     Database User name: NT AUTHORITY\SYSTEM     First 2KB of SQL: CREATE PROCEDURE [dbo].[CheckSessionLock] @SessionID as varchar(32), @LockVersion  int OUTPUT AS DECLARE @Selected nvarchar(32) SELECT @Selected=SessionID, @LockVersion = LockVersion FROM [ReportServerTempDB].dbo.SessionLock WITH (ROWLOCK) WHERE SessionID = @SessionID   Anyone else experience this, and fix it ?


Why input and output power of chargers don't match

I know that battery chargers are more than just transformers (they are switched-mode power supplies), still, shouldn't input and output power be equal? Example: Input: 110/240V and 1.5A Output: 19V and 3.42A (65W) In the case of Input above the power is obviously way more than 65W. If Input indicates maximums and maximum V and A are drawn, how does the charger dissipate the extra power to meet the Output power demand?


How do decision tree based ensembles like random forest deal with categorical ("factor") predictor variables? My guess would be that indicator variables are created for each factor via a one-hot-encoding (aka 1 of K coding) but I wonder if that is true? The reason I doubt it is that it seems that such a coding for a factor with many levels would of course results in many additional variables and the selection (random) of which predictors to consider for splitting at each node would not actually be picking "variable 1" or not, but instead would be selecting a potential subset of the indicators that resulted from "variable 1".   I was under the impression that Caret in R expanded all factors out using model.matrix in its train function before passing to (any) modeling algorithm including RF however so that made me reconsider.  Does anyone know how these things are treated?


What is the view on accounts shared by multiple users on Stack Overflow?

It has been my understanding that accounts are suppose to be for a specific user. This user, , is a company: . No doubt, this account has provided some quality answers. However, if a specific user cannot be identified, I don't think that the rep gain, rewards, or badges should be given. This should somehow be tagged as a 'Corporate User'. The rep has no real value when you can't be somewhat sure that the same person is giving the answers all the time.  This is where I found an answer by Devart: , peddling a product.    Edit 2 Good points have been brought up and most I can agree with. But we are setting a precedent. Meta Fudgey brought up a good point about the account's ability to use mod tools responsibly and consistently. Maybe this feature is not available to an account that appears to be an umbrella account unless a single user is identified. I think it is important to consider this aspect.    Let me re-iterate: the user(s) has provided excellent content and I would want that to continue. However, there is more at stake here than meaningful content and helpful resources.      Edit The view on 'shared' accounts wasn't so bright a year ago. For most of us, we have information in our profiles that identifies us as individuals. No, I don't have absolute knowledge of the activities on this account and how many people might use it. Meh, for all we know it could be a knowledgeable programmer with some good PR sense. On the other hand, it could be a PR person with no programming knowledge getting the answers from an employee. Who knows...


How does Indian Railways allot seats in case of change in boarding point?

I intend to travel on the Hampi express from SBC (Bengaluru City station) to Hospet. As only waitlisted tickets were available between these stations, I have booked my journey from Kengeri to Hospet and changed the boarding point to SBC. My ticket is currently .  How does seat allocation happen in such a situation? Is it based on the booking station or the boarding station?


My dad bought a Surface laptop for me. Can run Ubuntu on it? I tried and the keyboard does not work, so is there any version available that solves this problem?


How to indicate a picker control is going to be opened on a form field

I'm doing a form field on an app and need to included a drop down at the end of some of the text fields. For the android version I'll be using the material design standard as below.     I see that iOS doesn't endorse using a drop down but would show i picker instead. How do I visually indicate on the form that a picker control is going to be opened on a form field from a certain link or icon?


Building new dual boot PC: Does Ubuntu get installed first or second?

I'm going to build a new PC in the next few days that I want to be dual boot Ubuntu 16.04 and Windows 10 Home.  Which OS should I install first, and are there any special details for installing both OS on a new build?   I've only added Linux & Ubuntu to machines with an existing OS.  Thanks!


Relation between Earth's rotation-gravity and moving object on Earth

This might be silly question. It's about the rotation of the Earth and the objects moving on it. If I jump into the air, why did I also move with the Earth though I am in the air? I am supposed to be land in backward/forward location, as it keeps rotating. But this doesn't happen. What is this phenomenon called?


How to recreate this selected matcap material in Cycles? It's most glossy in the center and has this special coat.


Disable "Are you sure you want to quit this application"

Sometimes if an application like iTerm or XAMPP is running, and I try to shut down my Mac, it prompts "Are you sure you want to quit this application". It then disables the shutdown process until I click "No" or "Yes". Is there a way to configure my settings to disable the prompt from showing up and interrupting shutdown?


Should I state "the data are," or "the data is."

I have an Excel sheet with a series of variables and the formula output.  I am trying to report what the data is (are?).  Should I say the "data are suggesting," or "the data suggests"?  The latter sounds correct, but the former appears to be more accurate. Or does it even matter?


What's the shear rate in a turbulent flow?

The explanation of shear rate in laminar flow is straightforward: We imagine small layers of fluid that glide on each other. Now, in turbulent flow, this does not work as there are no layers. I'm not even sure that shear rate is a meaningful concept in turbulent flow.  If I want to know the apparent viscosity of a shear thinning (or other non-Newtonian) liquid, I need to know the shear rate. How do I know the shear rate in turbulent flow?


How to contest a gold badge duplicate closure as low-rep user?

I asked  to get a constructive response to the problem on how to get a host name for a client VM known to the host.  Another user then came by and closed as duplicate. Being a gold badge holder this took effect immediately. I suspect they did so without understanding the question fully.  Now I've tried to reopen and call moderator attention to this question, so I can get an actual response perhaps even a useful answer, but without prevail.  How should I approach this from here?    EDIT:  The duplicate has been removed, without me getting to editing the question as suggested.


What is the correct way to write the word "back-end"?

Back-end and front-end are common technical terms nowadays. Traditionally, they are written with a hyphen "back-end". Is there a rule in the English language that dictates this to be a correct way to write term, that signifies general single something? Or did it just "stick" that way?  Clarification 1: The proposed answer that discusses when to hyphenate assumes back-end as a compound word. I don't think it is and this am asking this question. Compound words like on-the-fly are comprised of possible standalone words that are all required to describe the phenomenon or thing in question.  Backend is a synonym to server-side, which really is a compound word. Backend is a singularization of server-side, not a compound itself.  I understand that I may have a logical "gap" somewhere in this line, the reason why I asked is to help me clarify this.


Show that the angle that a tangent line of a hyperbola forms with the intersection with a vertical line, and a focus is a right angle.

Question: Let $P(p, q)$ be a first quadrant point on $x^2/a^2 −y^2/b^2 = 1$. Let $D$ be the point where the tangent at $P$ meets the line $x =a^2c$. $F_2$ is the focus $(c, 0)$. Show that $∠DF_2P$ is a right angle. I believe the way to solve this problem is to confirm that the slope of $DP$ is the negative reciprocal of the slope of $DF_2$.But the points being $(p,q)$, $(a^2,y)$. and $(c,0)$ doesn't seem to get me there.


I'm trying to build the . When I run the command   make -s -j8 DEFAULT_TARGET=shared_release    it gives me the error of permission denied.


How can I create a URL for a specific cell in Google Sheets?

I am a teacher who is trying to create QR codes for book reviews to be placed on books in the library. I have collected all of my students' book reviews via a Google Form, so that their answers are on a Google Sheets (one column, about 100 rows). Instead of creating a QR code from the reviews and limiting the characters for the length, I'd rather have each review be a separate URL and use that address to create the QR code instead. Instead of creating 100+ different web pages or sheets in Google, if there was a way to create a link directly to a specific cell in the sheet that would be incredibly helpful. I tried to use the query formula (limit and offset) after publishing the web page and also not publishing it, but I get an error each time. I tried adding the range/cell using this URL:  but it comes up with the error page saying:  Sorry, the file you have requested does not exist. Please check the address and try again.  I'm not sure if I typed it in wrong or what. The code I used originally was: /gviz/tq?tq=limit 1 offset 32 It actually is working today to give me the limited row, but there are a lot of extraneous characters included (this is the actual link: )  Is there a way (or an easier way) to do this? Is there any way to keep the formatting of the Google Sheet?


Reflexive, symmetric or non transitive relations?

I'm currently doing work on discrete mathematics in my free time and am having some difficulties with understanding some questions pertaining to Relations and Functions. To be specific, I'm stuck on the following practice question:      Let A = {a, b, c, d}. Give an example of a relation R on A^2 which is     reflexive, symmetric and not transitive. Explain.   I don't really understand how to do reflexive etc., how would I find the resulting relation? Any help is appreciated! Thanks.


So I found out about the gamma function yesterday and I spent a bunch of time trying to evaluate certain values like $0.5!=\Gamma \left(1.5\right)$. I used multiple integration by parts, and in the end I always get $0=0$. How can someone compute gamma function values for all real numbers manually? I want to evaluate the integral by hand without using previous simplified equations for certain values. Thank you.


C++ Unresolved External on Class in Project

So I'm new to C++ and Visual Studio and I'm trying to implement a hash table using templates. I have four files: main.cpp, HashNode.h, HashTable.h, and HashTable.cpp.  main calls the HashTable constructor with a paramenter (the definition is in HashNode.h, with the implementation in the cpp file), but this throws 2 unresolved external errors: one for the called constructor, and one for what I assume to be the default constructor.  However, main also calls the HashNode constructor with no problems. HashNode has its implementation and declaration all in the HashNode.h file, but moving HashTable's implementation to its .h file didn't clear the error. So I'm very confused lol.  I'm running Visual Studio 2019, fresh install, and using the default build button to build it. It does compile and run other things (like hello world), just not this.  I've also tried adding random garbage into HashTable.cpp to see if the compiler just didn't see that it existed, but that's not the case. It also throws a compilation error then.  HashTable.h:  #pragma once #include "HashNode.h"  template <typename T> class HashTable {     public:         void AddItem(int key, T item);         T* GetItem(int key);         HashTable(int buckets);         ~HashTable();         int print();     private:         HashNode<T>** elements;         int buckets; };   HashTable.cpp:  #include "HashTable.h" #include "HashNode.h" #include <stdexcept>  template<typename T> HashTable<T>::HashTable(int buckets) {     elements = new HashNode<T> * [buckets];     for (int i = 0; i < buckets; i++)     {         elements[i] = nullptr;     }     HashTable::buckets = buckets; } ... //other methods defined below   HashNode.h  #pragma once  template <typename V> class HashNode { public:     HashNode(int key, const V value) : k(key), v(value), next(nullptr) {}     int getKey () const { return k; }     V getValue() const { return v; }     HashNode* getNext() const { return next; }     void setNext(HashNode* next) { HashNode::next = next; }     void appendToChain(HashNode* last)     {         HashNode* curr = this;         while (curr->getNext() != nullptr)         {             curr = curr->getNext();         }         curr.setNext(last);     } private:     int k;     V v;     HashNode* next; };   Main.cpp:  #include <iostream> #include "HashTable.h" #include "HashNode.h"  int main() {     std::cout << "Hello World!\n";     HashNode<int> node(1,1); //works fine     std::cout << node.getValue() << std::endl; //prints fine     HashTable<int> table(5); //throws error on compilation }   It's probably just something stupid or that I'm blind, but here's the errors:  Error   LNK1120 2 unresolved externals  HashTable   D:\C++\HashTable\Debug\HashTable.exe    1     Error   LNK2019 unresolved external symbol "public: __thiscall HashTable<int>::HashTable<int>(int)" (??0?$HashTable@H@@QAE@H@Z) referenced in function _main    HashTable   D:\C++\HashTable\HashTable\Main.obj 1     Error   LNK2019 unresolved external symbol "public: __thiscall HashTable<int>::~HashTable<int>(void)" (??1?$HashTable@H@@QAE@XZ) referenced in function _main   HashTable   D:\C++\HashTable\HashTable\Main.obj 1      Also, please don't hesitate to give me pointers if my code's bad. I've never really programmed anything in C++ before so any help is welcome!


How do I copy a file/folder from a DVD to my hard drive using the Terminal?


I recently installed the Java runtime (through Software Update) and enabled the Java browser plug-in and WebStart on Lion, but I don't need them anymore.  Unchecking "Enable Java" in Safari preferences gets the job done, but I'd rather get rid of Java completely. So the question is, how do I do this? I want to go back to a clean Lion install, Java-wise.


On proving that a finitely generated group has a finite number of subgroups with index $n$.

Theorem: If $G$ is a finitely generated group, then it has a finite (maybe zero) number of subgroups of index $n$ for any $n\in \mathbb{N}$.   is a sketch of a proof. It consists of assuming such a subgroup $H$ exists, and allowing $G$ to act on $G/H$ by left multiplication. Such action defines a homomorphism $$\phi :G \rightarrow \text{Sym}(G/H)\cong \mathbb{S}_n$$  If $G=\langle g_1, \ldots ,g_r\rangle$, then the homomorphism is uniquely determined by where it sends the generators $g_i$. In particular, there are at most $(n!)^r$ such homomorphisms.  The last step of the proof requires one to notice that a different subgroup $H'$ of index $n$ in $G$ would produce a different homomorphism, and here is where I'm struggling. I've been able to show that $\text{ker}(\phi )=\text{core}(H)$, yet haven't been able to rule out the possibility of $\text{core}(H)=\text{core}(H')$.


Can you be sued for using publicly used images on a blog without copyright permission?

Lets say I write a blog post about the new Batman movie or a the new Grand Theft Auto game and i decide to use the boxart/poster or a wallpaper as the main image for the blog post,  can I be sued for breach of copyright on this image?  Im pretty sure Warner Bros are going to be hunting anyone down even if it is legal, but is this actually legal? If i buy the DVD or Game and take a picture of it, is this my copyright? When a trailer gets released and put on youTube, can i take a screenshot of this video and use this as an image?  It seems people can get rightly screwed for this, so I would like to know where i stand on this sort of thing.


Looking for title of a scifi story about a class trip

I read a novel from the mid to late 80's where a class was transported for a survival weekend but the transporter malfunctioned and the group wound up on an unknown planet. I believe the kids were stuck there for a couple before being found. At the end of the book one of survivors journeyed back to the new planet with a type of wagon train of pioneers. Anyone know this book and if so its name?


does subversion support word, excel, powerpoint docs?

Does subversion support word, excel and powerpoint documents? "support" here means having history available and I can get old version out from the subversion. It will be nice if I can diff different versions.  thanks,


JS function only pick on first element in Django loop

My template code is as follows {% for content in contentlist %}

PRICE&nbsp;&#8208;&nbsp;                         {{content.price}}

       </div
            {% endfor %}  and I want to convert my price value into a comma-separated value using the js function. JS function is as follows window.onload=function(){   var price = document.getElementById("reservedPrice").innerText   x = updateTextInput(price)   document.getElementById("reservedPrice").innerText = x }  function updateTextInput(val) {   x = val.toString();   var lastThree = x.substring(x.length-3);   var otherNumbers = x.substring(0,x.length-3);   if(otherNumbers != '')       lastThree = ',' + lastThree;   var res = otherNumbers.replace(/\B(?=(\d{2})+(?!\d))/g, ",") + lastThree;   return res }  but in result looks . JS executing only on first entry. I want all prices to be comma-separated.


What is wrong with this funny proof that 2 = 4 using infinite exponentiation?

Out of boredom, I decided to recall the following equation:   $$x^{x^{x\cdots}} = 2.$$  Which, I simply rewrote like this:   $x^2 = 2$, and therefore $x = \sqrt{2}$.  Then I took a look at the more general form:  $$x^{x^{x\cdots}} = p.$$  I then concluded that $x = (p)^{\frac{1}{p}}$, and this was the solution set for all $p$. Then I thought for a while and determined that there are multiple values where this function equals the square root of $2$, so its not injective. However, this led to an awkward statemend based on the fact that $\sqrt{2} = (4)^{\frac{1}{4}}$. We deduce the following:  The equation $x^{x^{x\cdots}} = 2$ and the equation $x^{x^{x\cdots}} = 4$ have the same solution, namely $x = \sqrt{2}$. So we conclude that $2 = 4$.   I showed this to friend of mine, and he conjectured that there are no valid solutions for all $p > e$. To prove this, I tried writing the following:   I tried differentiating $f(x) = (x)^{(1/x)}$ and setting it equal to $0$ to find the maximum. I determined that there was a maximum at the point where $x = e$. Does this mean that the maximum possible solution $x$ for the infinite power is $e^{(1/e)}$ therefore showing that the maximum value for $p$ is indeed $p = e$?


Does Ubuntu 14.04 LTS work with only 736MB of RAM?

I want to install it on my old desktop PC. here is it's specs:   CPU: Intel Pentium 4@2.4GHz RAM: 736 MB VRAM: 256MB HDD: 120GB   I can install the following OSes on it:   Windows Vista Home Basic w/SP2 Mac OS X v.10.5.8 "Leopard" Ubuntu 14.04 LTS?


Proving $\kappa^{\lambda} = |\{X: X \subseteq \kappa, |X|=\lambda\}|$

Let $\kappa , \lambda$ be cardinals with $\omega \leq \lambda \leq \kappa.$   Prove $\kappa^{\lambda} = |\{X: X \subseteq \kappa, |X|=\lambda\}|$.  i.e could anyone advise me on how to construct a bijection between $\{f \mid \text{$f$ is a function},~{\rm dom}(f) = \lambda,~ {\rm ran}(f) \subseteq \kappa\}$ and $\{X: X \subseteq \kappa, |X|=\lambda\}$?  Thank you.


Prove or disprove: There exists a prime p > 3 such that p + 2 and p + 4 are also prime

I'm having a lot of difficulties with this proof. Can someone please solve it and explain to me what's going on at each step? Thank you!


Snapping multiple nodes of a polygon to the nodes of a line?

I am working with vector polygons that have derived from hand drawn areas from when mapping was carried out with tracing paper over paper maps. Therefore many of the polygons don't exactly line up to the boundaries on the ground.  Another dataset of vector lines I have is accurate and so I have been manually snapping nodes of the polygons to the nodes of the lines. But this is a lengthy process.  Here is a screenshot...    The green line is the accurate dataset. You can see how the polygon boundaries (orange) are roughly correct. Bottom left I have started to edit the nodes, with the snapping options set up, and this works to manually move the nodes of the polygons to snap to the nodes of the line. (Yes, I could have enabled topographical editing to move both the polygon boundaries together, and I do do that).  Is there a method for snapping multiple nodes of the polygon to the nodes of the lines, or is there perhaps a better method of doing this? Using Python perhaps? I am looking for something akin to the 'Enable tracing' function (which is great) but for moving polygon boundaries.  I am aware that this may in places be a duplicate as there are many similar questions, but I haven't quite found anything that answers my particular situation? In particular I have looked at...


How do I view, but not edit, the markup for any given comment on any given Stack Exchange site?

I found a comment to a post on one of the Stack Exchange sites at:    I see some special formatting that they used in the comment:    Yes, I know I can find out the special notation via the  button that is provided when you post a comment. But new users won't know about that help button that only shows up when you post a comment. Instead, I desire to view (but not edit) the unrendered comment text syntax, so as to see their specific notation.  Is there a way to do that? If not, then: This is an enhancement request for a tiny "View" button or icon right next to that comment that, when pressed, would popup that particular comment's text in a tiny form that I can use the mouse to select the raw markup text and copy it out for reuse. It might be best to provide an Edit button even if the current user does not have editing privileges, but only prevent them from posting the edit, but still allow them to select and copy the text out of the editing form.  Other helpful answers that were not exactly what I was looking for:


Bottles with balls inside - Physics Simulation

I want to create in blender a realistic physic simulation with bottles that have balls inside, first example is created Blender and the second in another 3D software. How to create this simulation in blender? I have to checked the normals, applied all transforms for scale, position and rotation, set Origin > origin to geometry, increasing the Steps per second and Solver Iterations in the Rigid Body World settings (I tried with the maxima 1000 and 100), set collision shape to Mesh and tried 0.4 or 0 as margins and source to final, but doesn't work..., the simulation is a mess...   I have attached here the blend file, Who can help me how to configure the rigid body settings to achieve a realistic result similar with the second example ?  Kind Regards!


I have several apps on my device that has multiple intent filters, which clutters the menu when I want to open a file(e.g. PDF). I would like to hide some of these intent filters, as I do not need them. This is a picture of the intent chooser:  I know that iOS has an option to hide these targets under the "More" menu, can this be done on Android? I am using One UI 2 (Samsung) and MIUI 10 (Xiaomi). Thanks


Using Halls Theorem to show Graph contains a perfect matching containing any edge.

I'm struggling on this question and any hints (not full answers) would be greatly appreciated.  Consider Bipartite Graph G with vertex Classes A and B of the same size.  I need to use Hall's Theorem to show that is |N(S)| > |S| for all subsets S of A then for any edge e, G contains a perfect matching containing e.  Thanks!


for some reasons, this code doesn't work in my document:  \documentclass{article} \usepackage{fancyhdr} % Required for custom headers \usepackage{lastpage} % Required to determine the last page for the footer \usepackage{extramarks} % Required for headers and footers \usepackage[usenames,dvipsnames]{color} % Required for custom colors \usepackage{graphicx} % Required to insert images \usepackage{courier} % Required for the courier font \usepackage{tikz} \usepackage{pgfplots} \usepackage{lipsum} % Used for inserting dummy 'Lorem ipsum' text into the    template \usepackage[francais]{babel} % For French \usepackage[latin1]{inputenc} % Standart input, need it for accents \usepackage{amsmath, amssymb} % Real number R, Complex C etc... \usepackage{sectsty}  % For title/section color \usepackage{xcolor} % For title/section color \usepgfplotslibrary{fillbetween} \pgfplotsset{compat=1.12}  \begin{document}  \begin{center} \begin{tikzpicture} \begin{axis}[axis lines=middle,samples=200]   \addplot[name path=f, blue] {x/((1+x^2)^2)};   \addplot[draw=none, name path = xaxis] {0};   \addplot[blue!30] fill between [of=f and xaxis, soft clip={domain=1:2}]; \end{axis} \end{tikzpicture} \end{center}  \end{document}   But if i use delete \usepackage[francais]{babel}, it's working. Howewer, i need this package to write in french.


How to deal with very long lstinline-phrases like long class names?

According to this Question:    My problem is that my \lstinline-phrases does not contain any special character like "-". In my lstlinlines there are very long class name like ThisIsAVeryLongExampleClassNameAndItHasNoLineBreak. The problem that results from those class names are overfull boxes.  Does anyone knows an approach how to set conditional line breaking marks. (Like \- in normal text).


Expectation $\infty$ but existence of $\mu$ weak convergence

I am trying to show the following: Let $\{X_i\}$ be i.i.d  with $P(X_1=(-1)^{k}k)=\frac{1}{ck^2log(k)}$ for $k\ge 2$ with $c=\sum_{k}\frac{1}{k^2log(k)}$ a normalizing constant. Show that $\mathbb{E}[|X_1|]\infty$ but there is a non-random $\mu_n$ such that $n^{-1}S_n-\mu_n\rightarrow 0$ in probability. My attempt is the following: $$\mathbb{E}[|X_1|]=\sum_{t=2}^{\infty}tP(|X_1|=t)=\sum_{t>2;t=2k}^{\infty}tP(X_1=t)+\sum_{t>2;t=2k+1}^{\infty}tP(X_1=-t)=\sum_{t=2}^{\infty}\frac{t}{t^2log(t)}=\infty$$ Since $X_1$ is unbounded I need to  show the $nP(|X_1|>n)\rightarrow 0$ in order to guarantee  existence of $\mu_n$ that is $n=o(P(|X_1|>n))$ Consider $P(|X_1|>n)=\sum_{t>\lfloor n\rfloor}^{\infty}P(|X_1|=t)=\sum_{t>\lfloor n\rfloor}^{\infty}\frac{1}{ct^2log(t)}$ since $\frac{1}{ct^2log(t)}\rightarrow 0$ as $t\rightarrow \infty$ then $\sum_{t>\lfloor n\rfloor}^{\infty}\frac{1}{ct^2log(t)}\rightarrow 0$ as $n\rightarrow \infty$. Since $\sum_{t>\lfloor n\rfloor}^{\infty}\frac{1}{ct^2log(t)}$ goes to zero quicker then n goes to $\infty$ then the desired property holds and the existence is guaranteed. Is this correct or is my approach completely wrong.


Are research survey questionnaires spam on Stack Exchange sites?

In  the asker is apparently carrying out an Ant v. Make research smackdown.  To me this looks like spam, but seems harmless.  Should anything be done?  Is there a policy on canvassing the community in this way?  Is it allowed?  As an aside, it seems like the OP would get more views with some language tags, rather than what's on there now...


C++ what is the point of "const" keyword?

What is the point of using the keyword const? for example when making a game, one of the first things to do is to set the width and height of it. And most of the time you'll use for example:   const int Width   and  const int height   Now I know that you should do it like that because the width and height of the screen will not change throughout the game, but what is the point of doing so ? you can do the same thing without using const and it will work just fine.  That was just an example. so what I'm confused about right now is:  What is the point of using the const keyword anywhere if you won't change the variable anyway?


I know how to use \LaTeX to get a fancy version of the word LaTex; I’ve seen a similar version of the spelling of BibTeX but \BibTeX doesn’t work. I’ve tried a few variants on capitalization and not hit on one that works.  The problem with searching about anything to do with BibTeX is there are so many articles on how to use it that this specific question does not show up in queries.  It  to do this:


Can I re-activate existing Windows 10 OEM installation by the phone robot? (Moving old SSD to new PC)

I know that OEM licenses cannot be transfered to new Windows installations, but in this case I am moving existing Windows 10 installation with the SSD to a new setup. My Microsoft-account is tied to the digital license. From the perspective of the SSD / W10 install, it would be the same installation with major hardware changes, right? If I need to re-activate Windows after moving the SSD, can I still do this thing?: Troubleshoot => I recently changed hardware on this device => This is the device that I'm using at the moment I say it again: I am not trying to re-activate inside a new installation, but the old installation that is on the SSD from the old PC setup.  EDIT: The question here  is similar but the OP tried to activate new install, instead of old install. Also the OP or others in that question never mention trying the phone activation so could that be a 50/50 solution? OP said that he tried to change the license key and got an error, but did he get the option to call phone activation? It should appear if there is a problem with the license key.


Mac won't boot up using Bootcamp after trying to resize partitions

my son is working on a 2012 Macbook Pro - 2.5Ghz Intwl Core i5 and running OS X El Capitan version 10.11.6. The machine was split into two partitions and windows bootcamp was loaded. My son told me that every time he tried to save a document on the windows side he got error message about no available disk space. I tried to resize the windows disk partition and when we tried to start-up again, bootcamp would not load (error saying no bootable device).   I have read through as many similar questions and answers as I can but am not able to solve the problem. REALLY want to avoid paying to have the windows reloaded. Any way someone in the know could help me?  Thanks KD


Which phrase is correct, "what happened is” or “what happened was"?


Libvirt: how to pass qemu command line args?

I have the current libvirt 1.2.20 i want to pass to my machine create with virt-manager some qemu flags. I edited the file and add    </devices>   <qemu:commandline>           <qemu:arg value='-L pc-bios'/>   </qemu:commandline> </domain>   But doesn't work i also tried to edit from virsh  virsh edit domain   and put   <qemu:commandline>           <qemu:arg value='-L pc-bios'/>   </qemu:commandline>   But give me this error  errore: XML document failed to validate against schema: Unable to validate doc against /usr/share/libvirt/schemas/domain.rng Element domain has extra content: qemu:commandline  Failed. Try again? [y,n,i,f,?]:    How to pass correctly qemu command line? Thanks


Can the links be disabled in the vote-to-close dialog?

Over the time I've been able to vote for closure on SO, I've gotten into the habit of clicking on the reason itself in order to select the radio button corresponding to it. Since the reasons have changed, there are also now links in the middle of the text, which I also happen to accidentally keep clicking on. More annoyingly, these links don't open in a new tab so I have to click back and redo it. This happens most often with the "FAQ" link in the off-topic dialog, which is right there in the top left corner where I normally click.        Basically, those pieces of text now have two functions. One function of it is selecting the corresponding radio button and the other function is loading a new page. Obviously loading the new page trumps simple selection.  This has become even more painful now with the new off-topic messages, where a large portion of the message is a link:        A simple feature request: can the vote-to-close dialog itself not render the links?


How to relate beta CDF to student-t CDF?

We can relate the student-t and beta distributions as such:  If $X$ has a Student's t-distribution with degree of freedom $\nu$ then one can obtain a Beta distribution: $$\frac{\nu}{\nu + X^2} \sim \text{B}(1/2, \nu/2)$$  If our goal is to compute the CDF of the student-t at a point $x$, how would we do this using the beta CDF? For example, I can compute the CDF of the beta distribution given by the incomplete beta function $$I_{x=0.4}(a=1/2, b=1/2) = 0.43590578$$ I guess in this case $b=1/2 \implies \nu = 1$. But for the incomplete beta, we need $0\leq x \leq 1$. So how would we evaluate the CDF of the student-t if, say if $x=-1$ and $\nu=2.4$ ? Using the transformation above, I didn't get matching results $$z = \frac{\nu}{\nu + X^2} = \frac{2.4}{2.4 + (-1)(-1)} = 0.705882352941$$ $$\text{student-t CDF}(\nu=2.4, x=-1) = 0.203620621107$$ $$\neq$$ $$I_{z=0.705882352941}(a=1/2, b=\nu/2=1.2)=0.8826576230306$$


A basic question about exponentiation: when is $a^{xy}=(a^x)^y$?

This is a silly question but under what conditions is $a^{xy}=(a^x)^y$ true, given all are complex numbers?


so im new to blender and just have a small problem. in the 3d view my animation looks like this   Then When I render it it turns purple like this   Anyway I can get it to render normaly so the pokeballs and writing isnt purple?


I've just been awarded a 3 year Schengen multiple entry visa with 90 days "duration of stay".  Does this mean that I only have a total of 90 days to visit the Schengen area over 3 years i.e. each trip counts towards this total?


If a moderator reviewed my flag, how was it disputed?

I saw the following in my flag list today:    Huh? This doesn't make sense. The only way a flag like this can be disputed is by being reviewed by a 10k+ non-moderator. However, if that is the case, then why does it say that a moderator reviewed it?


I just started to do cubes on blender... And I pressed a key(don't know which one) and I only see a part from all the scene.    I don't know how to make reference to this for searching what did I press...  Can someone explain me what did I do and how to reverse that?  Thank you so much.


Is it ok to add comments/answers to old questions?

Is it ok to revive old questions (e.g. last answer/comment older than 6 months) with new comments and/or answers?


How to create a user with limited RAM usage?

So I have 4 GB RAM + 4GB swap. I want to create a user with limited ram and swap: 3 GB RAM and 1 GB swap. Is such thing possible? Is it possible to start applications with limited RAM and swap avaliable to them without creating a separate user (and not installing any special apps - having just a default Debian/CentOS server configuration, and not using sudo)?  Update:  So I opened terminall and typed into it  command: ulimit -v 1000000 which shall be like 976,6Mb limitation. Next I called ulimit -a and saw that limitation is "on". Then I started some bash script that compiles and starts my app in nohup, a    nohup ./cloud-updater-linux.sh  >& /dev/null &... but after some time  I saw:    (which would be ok if no limitations were applied - it downloaded some large lib, and started to compile it.)  But I thought I applied limitations to the shell and all processes launched with/from it with ulimit -v 1000000? What did I get wrong? How to make a terminal and all sub processes it launches be limited on ram usage?


What happens to photons under the action of gravity?

Since light is affected by gravity, it seems like it is made of massive particles. So what happens to that mass when the photon is absorbed by a material?


Since ads are almost inevitable on official YouTube app on Android device, I was wondering if those can be skipped automatically?  This post is only about those ads which can be skipped, lets ignore ads which can not be skipped.  For example: When YouTube video starts, for some ads, there is an option to "Skip this ad in 5 sec".   Once "Skip ad" label is enabled, we can click on it to move to video. Of course this is all manual, and as a user you need to focus on EXACT timing to HIT the skip button. And it becomes worse if the video is having multiple Ads(few of which will be shown in future time), where when Ad plays, user need to again click manually to skip it.  Can this be AUTOMATED, meaning when there is an Ad which can be "Skipped", then just let the YouTube skip it without user's intervention.   This will be specially useful for those videos which has multiple Ads spanned across the video length and few of them can be skipped.  Looking for a solution on non-rooted device.  Update: It seems like Google is introducing new ad format called .  Bumpers, which are unskippable 6-second shorts placed in front of videos.      So, soon we may not see an ad which can be skipped, forget about   skipping it via automation!


Showing that the conjugates of a proper subgroup do not cover the group.

I am trying to figure out the following.  Suppose $G$ is a group and is finite; let $H$ be a proper subgroup. Show that the conjugates of $H$ do not cover $G$ (that is, there is some $g \in G$ which is not conjugate to an element of $H$).  As I understand it, we say that given $a,b \in G$, $a$ is conjugate with $b$ if $\exists g' \in G (a = g'bg'^{-1})$. Since $H$ is a proper subgroup of $G$, then there $\exists g \in G$ such that $g \notin H$. Since $g \notin H$, then $\forall h \in H (g \neq h)$. Suppose then that $\exists q \in G, \exists r \in H (g = qrq^{-1})$ $-$ i.e., that $g$ is conjugate with with some element of $H$. Then $q^{-1}gq = r$. However, I'm not sure where to go from here. I'm guessing that I have to somehow use the assumption that $G$ is finite however I'm not sure how to.


Transiting via Shanghai Pudong International Airport

i intend to travel to Osaka, Japan via Shanghai Pudong International Airport on China Eastern Airlines.  Since i only have a 4.5 hours transit at the Shanghai Pudong International Airport, do i need a Transit Visa in this regard? or can i do an Airside/Direct Transit at Shanghai Pudong International Airport without crossing/entering the Border Control?


Generalized Poincaré Inequality on H1 proof.

Let $\Omega\subset\mathbb{R}^n$ be a bounded domain. And let $L^2\left(\Omega\right)$ be the space of equivalence classes of square integrable functions in $\Omega$ given by the equivalence relation $u\sim v \iff u(x)=v(x)\, \text{a.e.}$ being a.e. almost everywhere, in other words, two functions belong to the same equivalence classes if they only are different in a zero meassure set.  This space is a Hilbert space with the norm is:  $$ \Vert v \Vert ^2_{L^2 \left( \Omega \right) }= \int_\Omega v(x)^2\,\mathrm{d}x $$  Let $H^1\left(\Omega\right)=\left\{ v\in L^2\left( \Omega \right);\,\vert\mathbf{grad}(v)\vert \in L^2\left( \Omega \right ) \right\}$ be also a Hilbert space and its norm :  $$ \Vert v \Vert ^2_{H^1 \left( \Omega \right) }= \Vert v \Vert ^2_{L^2 \left( \Omega \right) } + \Vert \vert\mathbf{grad}(v)\vert \Vert ^2_{L^2 \left( \Omega \right) } $$   I've been asked to prove that:  $$ \Vert v \Vert ^2_{H^1 \left( \Omega \right) } \le C\left( \Omega\right) \left( \Vert \vert\mathbf{grad}(v)\vert \Vert ^2_{L^2 \left( \Omega \right) } + \int_\Gamma \left ( \gamma v(x) \right) ^2\,\mathrm{d}\sigma \right) \quad \forall v\in H^1 \left( \Omega \right) $$  where $\Gamma = \partial \Omega $, $\Omega $ is smooth enough, $\mathrm{d}\sigma$ is a meassure on the boundary of $\Omega$, and the operator $\gamma: L^2\left( \Omega\right )\mapsto L^2\left( \Gamma\right )$ is the trace operator. ( if it is needed I can define it also )  Sincerely, I just don't know how to begin, and maybe someone could give me some clue about it.(by the way the $C$ is a positive constant depending only on the domain $\Omega$).  Thank you very much!


Python command within script to abort without killing Blender

When using the Text Editor, what is the best command to include inside a script which will abort the script at that line?  quit() and sys.exit() stop the script, but also kill Blender.


Google pre-rendering causing double and triple events

Is it possible to detect google chrome and firefox prerendering on the server side, or in .htaccess, and defer the prerendering for the purpose of monitoring traffic and website events, or do I need to move my website event tracking into javascript. =/  I am using laravel and angular js.


How can I prove that this Group is Abelian?

$(G,\cdot)$ a group. If $\exists n\in \mathbb{Z} $ such that $(a\cdot b)^{n+i}=a^{n+i}\cdot b^{n+i}$ for   $i=0,1,2.$ $\forall a,b \in G$.  Prove that $(G,\cdot)$ is Abelian. I'm not sure how to prove this. Why $i$ must be 0 ,1 or 2?


I've been using LaTeX for a couple of years, but I'm pretty new to the tikz package. In particular, I'd like to add Karnaugh's maps in my document. I've already found a solution that satisfy me (can be found here: ), and I'd like to slightly adjust it to make the boolean params appear at the very first cell which I want it to be diagonally split like in this example: .  Would anybody help me? Thanks in advance!


My understanding is that the last change date(in /etc/shadow) is the number of days since 01/01/1970 that the password was changed, but I'm seeing numbers like 19708 which translate to 17/12/2023 (future).  How is it so?


WordPress default setting is, most recent post is the first post of the blog.  But, I need to "Most commented post should be the first post in the blog". ( Categories page as well as home page)


uk standard visa - how much money is needed in bank for indians

My case: Country: India: Need: Standard UK visa Tickets: Tickets are already booked. Now i saw that that it's recommended not to book tickets prior to visa.   Accommodation and food: Have a sponsor in UK Query 1: I have a consistent 1.5L-2L bank balance since 6 months, a job in MNC. We have 2 applications to make. I think the money is enough even if flight tickets were not booked but how much is the money they have as ballpark to decide whether it's enough or not ? Query 2: Is it ok to tell that I have already booked refundable airline ticket so 2L is ok ? i dont want them to think I'm trying to be overconfident about my visa so booked tickets in advance.  Thanks, Pragati


Convolution of two Gaussians is a Gaussian

I know that the product of two Gaussians is a Gaussian, and I know that the convolution of two Gaussians is also a Gaussian. I guess I was just wondering if there's a proof out there to show that the convolution of two Gaussians is a Gaussian.


I found a nice general formula for the Taylor series of $\tan x$:  $$\tan x = \sum_{n\,=\,1}^\infty \frac {(-1)^{n-1}2^{2n} (2^{2n}-1) B_{2n}} {(2n)!} x^{2n - 1} $$  where $B_n$ are the Bernoulli numbers and $|x| < \dfrac {\pi} 2$.  I've tried Googling for a proof but didn't find anything. Hints would be appreciated too.  I am using the typical definition of the Bernoulli numbers:  $$\frac x {e^x - 1} = \sum_{n\,=\,0}^\infty \frac {B_n x^n} {n!}$$


back-up: which patitions to back-up before upgrading/reinstalling

I have Ubuntu13.04 on my laptop. I have to upgrade it to the next release or else I would install a fresh release after deleting my current system.  I have already installed and configured my current system a lot and I can't take the burden of doing it all over again if I install the next release. Now I would like to know that what all back-ups are required to be taken beforehand so that I would recover all my files/installations/configurations etc. In other words I should have everything on my new system (simply by restoring from back-ups) that I possess currently.  My current system has /, /boot, /home & swap partitions which were created by me when I had freshly installed the O.S.


Which of the following sentences is correct?        The number of apples is half the number of pears   The number of apples is half of the number of pears


Where did the kinetic energy formula come from?

I was looking for a proof for it and all rely on the work-energy theorem. But the work energy theorem relies on the kinetic energy equation. Ergo circular logic. So where did it come from?


Why is the Hillshade Styling contouring instead of shading in places?

I have this DEM file that's I've colored by altitude.   When I try to do a hillshade on this DEM I get some contouring and very dark shading.   Could someone give me a hint as to what I need to correct?  When I use the Processing Tool in the Raster Analysis Menu I get a similar result.  Ultimately I want to use multishading, but when I check that on it goes all black.