What is the best way to downsample photos to increase sharpness?  If I have a photo in raw format with a resolution of about 24MP. How do I best downsample it to increase sharpness if I think the original is soft? I’m avare that this will reduce maximum print size for a given dpi but I am wondering what the best downsampling method is.  My intuition tells me that scaling down by an integer factor using area avarage probably is quite good but can I use more information to get even better results?  Can the knowledge of raw pixel values before debayering be used for example?  This differs from this () question in that that question wants to preserv grain charachteristics which as far as I understand can be comparativly high contrast micro structure. While this question asks about how to increase sharpnes of soft photos (most likely from a soft lens) which is a more gradual smear.


Currently, the only way to cancel stars in a chat transcript is when the chat-message is visible in the chatroom's sidebar.    However, in a fast-moving, multi-star chatroom, the window of opportunity to cancel can be short, and rapid changes in starring can quickly make this impossible to do in a timely way.  We use stars as markers in moderator chat events (where the Community managers disseminate important information to the moderator teams) as well as for town halls during elections.  Feature request: Allow mods/room owners to cancel stars from the chat message menu box, including in the transcript.


What kind of pump do I need for this valve?

This is the valve I have on my bike, but my current pump does not work with it. What kind of pump do I need to buy that will work with it?


I'm currently using Ubuntu 13.04 on my ASUS F201E laptop. I'm trying to install  I want to install Linux Mint 13 "Maya" - MATE (32-bit) because it's meant to be more compatible with my hardware.  I've already created a bootable USB (sudo dd if=./linuxmint-13-mate-dvd-32bit.iso of=/dev/sdb) with the new OS on it no problem, and am now trying to reboot and install this new OS on my laptop.  My USB is recognized in the BIOS, (lets me open "EasyFlash" Utilities) however it's not recognized in the boot preference order - at the moment it only shows Ubuntu (but in the past has recognized a USB here too... The only boot option that shows is my normal Ubuntu).  I've played around with other BIOS settings, nothing seems to work. My fast boot is disabled, my launch CSM is disabled. There is an Add New Boot option, and when I open it, I'm asked for a pathway and I don't know how to write a pathway to my USB. My SATA mode selection is IDE (I changed this, can always change it back if need be.) Serial ATA port 0.


How am I to "[u]se induction to show that $n$ straight lines in the plane divide the plane into $\frac{n^2+n+2}{2}$ regions"? It is assumed here that no two lines are parallel and that no three lines have a common point. Further, this is not a non-Euclidean problem, but I wouldn't mind a discussion on the non-Euclidean nature of the problem.  I was thinking it might be easier to show using the unit sphere.    A GOOD REFERENCE I FOUND THAT WILL BE USEFUL TO ANYONE COMING ACROSS THIS PROBLEM IS Concrete Mathematics, Graham, Knuth, Patashnik pp. 4–8.


First, I'm really sorry for the weird title as I don't know what's the best way to describe. I'm a self-learner in C and there is a problem when I try to print the character. Here is the code:  #include <stdio.h>  main() { int num; float amt; char ch; long int pop_of_Indian; printf("value of num: "); scanf("%d", &num); printf("value of amt: "); scanf("%f", &amt); printf("one character: "); scanf("%c", &ch); printf("Indian population: "); scanf("%ld", &pop_of_Indian);  printf("NUM = %d\n AMT = %f\n Code = %c\n population of India is %ld\n", num, amt, ch, pop_of_Indian); }   Everything runs smoothly until the code required the character from user:   However, when I run the character part separately, it runs normally:  #include <stdio.h> main() { char ch; printf("one character: "); scanf("%c", &ch); printf("Code = %c \n", ch); }   What am I doing wrong here?


Will a tagged question which is both favorite and ignored still show up?

On stackoverflow I have Emacs as a favorite tag, and many tags involved with HTML ignored. However, there could be the scenerio of an HTML user wanting advice about Emacs, I would still like to see those questions. Will I still see the questions tagged both Emacs and HTML?


Given $p$ is prime and $y$ is a constant. What's the fastest possible way to find $x$ where $x^2\equiv y\bmod p$? Example: $x^2\equiv97\bmod101$ would give us $x=81$ as one of the solutions. What's the fastest way to compute any one of the solutions of $x$? Constraints:  $0\le p\le10^9$ $0\le y\le p$ $0\le x<p$


I get disconnected from the internet whenever the speed reaches 2.5 Mbps  Is there any app to limit the internet speed below that. I am not talking per application based.  Using MacBook Pro (mid 2013) Yosemite


Systems of linear differential equations - eigenvectors

Solve the following system of equations  $ \begin{cases}  x_1^{'}(t)=x_1(t)+3x_2(t) \\  x_2^{'}(t)=3x_1(t)-2x_2(t)-x_3(t) \\  x_3^{'}=-x_2(t)+x_3(t)\end{cases} $.  First, I create the column vectors $X$ and $X^{'}$. Then the matrix $$A= \begin{bmatrix} 1 & 3 & 0  \\ 3 & -2 & -1 \\ 0 & -1 & 1  \\ \end{bmatrix} $$  Now, I find the eigenvalues, $-4,3,1$ and their corresponding eigenvectors $(-3,5,1)^T (-3,-2,1)^T (1,0,3)^T$.   I'm just not sure how to take it from here and solve the system of differential equations. I want a diagonal matrix $D$ so that I can read the solutions easy, but I'm not sure how to do it.  EDIT   Building on @Francisco 's answer, I'd have that:  $$X=c_1  (-3,5,1)^T  e^{-4t}   + c_2 (-3,-2,1)^T e^{3t} + c_3 (1,0,3)^T e^{t} $$.  But I believe this could be written in a simpler form.


How can I measure the execution time of a script?

How would I measure the time it takes for a script to run from start to finish?   start-timing    //CODE  end-timing


Re-applying to medical school after misconduct

I am a nontraditional applicant for medical school and wanted to ask questions about my application here. I was previously enrolled in another MD program. I had an undiagnosed disability that resulted in some abnormal behavior, including research misconduct (data fabrication). It led to me withdrawing from medical school program, but I have spent several years recovering. I have finished a PhD. I have published many papers including a few at top journals (Cell) since then. I maintain a strong interest in academic medicine and I am ready to take another go at it. How might my application be processed differently? How successful could an applicant like myself be? Do you have advice on how I can present myself in the best manner? Do I have a chance?


What does the refractive index depend on?

I've always thought refractive index is dependent on the density of the material. The more denser, the more refraction. But kerosene whose density is higher than water has refractive index less than water. On running a google search,i found out that it is dependent on the atom types.But i am unable to understand how.Can someone please give me a simple explanation?


I want the following figure layout:  How it can be done?


Generating ordered combination of numbers

I can form numbers with only 0,2,4,6,8.  The sequence is as follows  0,2,4,6,8,20,22,24,26,28,40,42,.....  How to generate an ordered sequence of numbers from combinations of 0,2,4,6,8.


How to indent an heredoc inside an heredoc the right way?

The following codepiece is a script used to install Apache. I run this script in-place when executing it from the heredoc block that wraps it (APACHE).   Note that inside this APACHE heredoc, I have an internal heredoc (MOD_REWRITE), which I can refer to as a "secondary" or "internal" heredoc.  Please also note that all the code inside APACHE is indented (tabulated), besides the code of the internal heredoc.   bash /dev/fd/10 10<<'APACHE'      # Setup basics:      apt-get update -y && apt-get upgrade -y     apt-get install tree zip unzip     a2enmod mcrypt && a2enmod mbstring      # Setup LAMP environment with enabled mod rewrite:      echo -e "\07" && echo -e "\077" # Insert password.     apt-get install lamp-server^ -y     a2enmod rewrite  cat <<MOD_REWRITE >> /etc/apache2/apache2.conf  <Directory /var/www/> Options Indexes FollowSymLinks AllowOverride All Require all granted </Directory> MOD_REWRITE      systemctl restart apache2.service      # Setup maldet:      cd /usr/local/src     wget http://www.rfxn.com/downloads/maldetect-current.tar.gz && tar -xzf maldetect-current.tar.gz     cd maldetect-* && bash ./install.sh  APACHE   If I indent it with commands with spaces instead of tabulations, I can run the script just fine (as long as it doesn't have the MOD_REWRITE inside it). If I add the MOD_REWRITE, the script brakes when executed; The same happens if I remove all space-indents whatsoever and totally replace them with tabulations, but AFAIK, the last time I tried to execute the script with tabulations, it also broke (even when I added an hyphen between bash /dev/fd/10 10<< and 'APACHE'.  My question:  What is the right way to indent the MOD_REWRITE heredoc inside the APACHE heredoc, so the script would be more unified and would execute without breakage?  Notes:   The reason I want to indent internal heredocs as well, just as I would do with any other command, is from aesthetic reasons --- It makes it easier for me to read and organize my scripts. This question is not the same as "" because it asks about the correct way of indenting internal heredocs inside external heredocs, and not about indenting external heredocs themselves.


Is there any difference between a one-time pad and a Vigenère cipher with a long key?

I've been browsing Wikipedia and stumbled on the article for the Vigenère cipher. I realized after seeing the example that it's quite similar to the one time pad, except with a short key repeated as the source of "random" information. That is, if you make the key longer than the plaintext, the two are the same.   Is that correct?


How can I make my title wrap in a tikzposter

I'm making a poster using the tikzposter document class, it's working nicely except that my title is too long and I can't make it wrap, I've tried \\, \protect, \newline and \par. \\ and \par throw errors and \newline does nothing.  Here's my code:  \documentclass[25pt, a0paper, portrait, margin=10mm, innermargin=15mm, lockverticalspace=15mm, colspace=15mm, subcolspace=8mm]{tikzposter} \title{Making posters with really long titles: The hassles of using \LaTeX when I could be doing it in some WYSIWYG editor instead.} \author{frogamic} \institute{University} \begin{document}   \maketitle   \block{Intro}{Intro stuff}   \begin{columns}    \column{0.5}       \block{Method}{Method stuff}     \column{0.5}       \block {Results}{Results stuff}   \end{columns} \end{document}


How can I change the appearance of the "figure" counter?

In the following code the figure number is shown as 1.1. How can I change the figure number format to 1-1?  \documentclass{book} \usepackage{graphicx} \usepackage{caption}   \begin{document} \chapter{One} test \begin{figure}[ht!] \centering  \includegraphics[scale=0.5]{10.png} \caption{} \label{handle} \end{figure}  Figure \ref{handle}. \end{document}


Is the axiom of choice used in the proof that every open set is the union of basis elements (Mukres, Lemma 13.1)

Here is a Lemma from the Munkres' topology.     Lemma: Let $X$ be a set and let $B$ be a basis for a topology $T$ on $X$. Then, every element of $T$ is equal to the union of some elements of $B$.   In the proof, Munkres' writes that given $U \in T$, choose for each $x\in U$ an element $B_x$ of $B$ such that $x\in B_x \subset U$.  Am I correct that when he chooses $B_x$ he is in fact using the Axiom of Choice?


Time out problem while installing wireshark

I am getting following error message when I am trying to install wireshark using:  sudo apt-get install wireshark   output:  Err http://us.archive.ubuntu.com/ubuntu/ oneiric/universe libsmi2ldbl amd64 0.4.8+dfsg2-4   Could not connect to 10.1.101.150:3128 (10.1.101.150), connection timed out   Please help me to come out of this problem...


Python, Sqlite3 - How to convert a list to a BLOB cell

What is the most elegant method for dumping a list in python into an sqlite3 DB as binary data (i.e., a BLOB cell)?  data = [ 0, 1, 2, 3, 4, 5 ] # now write this to db as binary data # 0000 0000 # 0000 0001 # ... # 0000 0101


pgfplots/gnuplot: How to find the curve-fitting function passing through certain points and plot it?

Considering this code, I would like to know how to find the curve-fitting function passing through the first four points (i.e. X=[0,3]) and plot this function (e.g. the red dashed line in the desired output below).  \RequirePackage{luatex85} \documentclass{standalone} \usepackage{pgfplots, pgfplotstable} \pgfplotstableread{% X Y 0 0 1 1 2 4 3 9 4 12 5 15 }\datatable  \begin{document}     \begin{tikzpicture}     \begin{axis}[xmin=0,xmax=5,ymin=0,ymax=20]     \addplot [only marks, mark = *] table {\datatable};     \end{axis}     \end{tikzpicture} \end{document}     Desired Output


Let's say I have a c# class which can be subscribed to like so:  public class Emitter {   public delegate void EmitAction(Emitter emitter);   public event EmitAction OnEmitted;    public void DoEmit() {      if(OnEmitted != null)        OnEmitted(this);   } }   ...and another class that makes use of it:   public class EmissionUser {     public void SomeFunction() {       Emitter em = new Emitter();       em.OnEmitted += HandleIt;       em.DoEmit();    }     public void HandleIt(Emitter em) {       //I could just do em -= HandleIt, but is there any point?    } }   I know that for code cleanliness and avoiding memory leaks, it's always good have one unsubscribe for every subscribe when using events.  However in a case like this, the Emitter instance is created locally in SomeFunction(), and not held in memory for too long, so I'm guessing the event subscription is destroyed with the local instance.  Is it still a good idea to unsubscribe in the handler?  If so why?


We have a need for equipment to post status updates to salesforce. Unfortunately the equipment lives on a secure network that will not allow return communication The methods I see all require a request for an auth token and then use that token to post to the rest method.  Is there a way to do this in one shot just straight post to the rest method with a preset token or a combo password api token?


I installed my Ubuntu in vmware, no I need install vmware tools, I got error:  Searching for a valid kernel header path... The path "" is not valid. Would you like to change it?[yes]  In CentOS, I run the following commands to resolve this issue: yum install gcc-c++ yum install kernel-devel yum install kernel-headers yum -y update kernel  But I don't know how to do in Ubuntu. I have tried the following commands but nothing changed sudo apt-get update  sudo-get install build-essential linux-header-$(uname -r) sudo ./vmware-uninstall-tools.pl sudo ./vmware-config-tools.pl sudo ./vmware-install.pl  Issue Changed: Ran sudo ./vmware-uninstall-tools.pl  and deleted the folder of /etc/vmware-tools then I ran  sudo ./vmware-install.pl  Now I can successfully install vmware-tools. After restart, I can see the folder /mnt/hgfs, but can't see my shared folder.


Why a backslash displays as "W"+strikethrough in Netbeans?

I'm facing a strange problem with Netbeans. In the editor, when I type a backslash(), I see a W with a strikethrough (as shown in the attached image).  So the c:\\abc is displaying as:    But, when I copy and paste that string into notepad, it gets pasted normally (i.e. c:\\abc).  Has anyone faced this problem before? How to fix it?


How to define a command that takes more than 18 arguments

This question is based on . It is a continuation of my previous qestion regarding  in latex.  According to first link there is a limitation on the number of arguments I have faced with.  I tried to use specified approach and it works well.  But what if I want to have more than 18 arguments?  Is it possible to use such approach recursively?  For example I want to define a function with 25 arguments. Is it possible to use next:    \newcommand\ParseOptMenuItemStoreA[9]{%     \def\tempa{#1}%     \def\tempb{#2}%     \def\tempc{#3}%     \def\tempd{#4}%     \def\tempe{#5}%     \def\tempf{#6}%     \def\tempg{#7}%     \def\temph{#8}%     \def\tempi{#9}%     \ParseOptMenuItemStoreB }  \newcommand\ParseOptMenuItemStoreB[9]{%     \def\tempj{#1}%     \def\tempk{#2}%     \def\templ{#3}%     \def\tempm{#4}%     \def\tempn{#5}%     \def\tempo{#6}%     \def\tempp{#7}%     \def\tempq{#8}%     \def\tempr{#9}%     \ParseOptMenuItem }  \newcommand\ParseOptMenuItem[7]{%     % Access to arguments #1-#18 via \tempa-\tempr and to argument #19-#25 via #1-#7. }   I tried to compile it but I got an error:  ! Missing number, treated as zero. <to be read again>                \protect l.40 }     So what I do wrong?  UPDATE 19.08.2015:  I have used next construction to achieve my goals:  \newcommand{\ParseOptMenuItemList}[1] { \def\tmplist{#1}% \@tempcnta=\z@ \@for\tmp:=\tmplist\do{\advance\@tempcnta\@ne \expandafter\let\csname temp\@roman\@tempcnta\endcsname\tmp }% \makebox[\linewidth][r]{%     \begin{tabular}{lc}         Possible values: \ifthenelse{\equal{\tempi}{}}{}{& \tempi\\}         \ifthenelse{\equal{\tempii}{}}{}{& \tempii\\}         \ifthenelse{\equal{\tempiii}{}}{}{& \tempiii\\}         \ifthenelse{\equal{\tempiv}{}}{}{& \tempiv\\}         \ifthenelse{\equal{\tempv}{}}{}{& \tempv\\}         \ifthenelse{\equal{\tempvi}{}}{}{& \tempvi\\}         \ifthenelse{\equal{\tempvii}{}}{}{& \tempvii\\}         \ifthenelse{\equal{\tempviii}{}}{}{& \tempviii\\}         \ifthenelse{\equal{\tempix}{}}{}{& \tempix\\}         \ifthenelse{\equal{\tempx}{}}{}{& \tempx\\}         \ifthenelse{\equal{\tempxi}{}}{}{& \tempxi\\}         \ifthenelse{\equal{\tempxii}{}}{}{& \tempxii\\}         \ifthenelse{\equal{\tempxiii}{}}{}{& \tempxiii\\}         \ifthenelse{\equal{\tempxiv}{}}{}{& \tempxiv\\}         \ifthenelse{\equal{\tempxv}{}}{}{& \tempxv\\}         \ifthenelse{\equal{\tempxvi}{}}{}{& \tempxvi\\}         \ifthenelse{\equal{\tempxvii}{}}{}{& \tempxvii\\}         \ifthenelse{\equal{\tempxviii}{}}{}{& \tempxviii\\}       Default value: & \tempxix\\     \end{tabular} } }   \ParseOptMenuItemList takes values as a comma separated list.


Need help after accidentally deleting partition!

I had Ubuntu on a partition with important files and I accidentally deleted the partition with Ubuntu and installed Windows on that partition.  I used disktest in live Ubuntu to get files from different partitions back but the one with Windows currently installed I had no luck. Should I uninstall Windows and then try to get files from the partition back that had Ubuntu installed?  Please help, these files are really important! The Windows installation is on the drive I need to return!


Combinatorial proof or meaning of the identity

I have to give a combinatorial proof and the meaning of the following identity.  $$\sum_{k = 1}^n (-1)^k k !S(n,k) = (-1)^n,$$ where $S(n,k)$ is the Stirling number of the second kind.  Could anyone give me a hint on how to go about this? I suspect it has something to do with surjective maps, since I know that $k!S(n,k)$ is the number of bijective maps from $n$ to $k$.


Mentally-linked clones soldier pairs fight wars and nearly destroy the Earth

This was a trilogy about a future earth where double clones were made to fight wars and they nearly destroyed the earth. They were good fighters because they were mentally linked. All were supposedly destroyed but a few were found by this reporter type.  I believe the USA version were called Jeeks.  In the second book a space ship containing a bunch of them returned.  In the final book one clone of a command 3 person clone fought them (the other 2 in the triad were killed and somehow this one did not go insane).  I have looked for this book for 30 years.


I have a connection through Microsoft SQL Server management studio that allows me to connect to a cluster database with a display name of the server and username along with password...  I have tried to connect my perl script to this database but keep getting this error in my IDE  DBI connect('ntcasdg3-db2\ntcafde4-db1','helping',...) failed:  [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified (SQL-IM002)  at C:/Users/harry/workspace/DataEx/DexDatabaseConnect.pl line 9 couldn't open database: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified (SQL-IM002);  stopped at C:/Users/harry/workspace/DataEx/DexDatabaseConnect.pl line 9.   Does the management studio use a different method to connect to the database that isn't available within Perl?  This is my current code:  #!c:\perl\bin\perl.exe -w  use DBI;  $db_user = "helping"; $db_pass = "helper"; $dsn_name= 'dbi:ODBC:ntcasdg3-db2\ntcafde4-db1';  my $dbh = DBI->connect($dsn_name, $db_user, $db_pass) or die "couldn't open database: $DBI::errstr; stopped";  my $sth = $dbh->prepare(<<End_SQL) or die "Couldn't prepare statement: $DBI::errstr; stopped"; SELECT vendor FROM dbo.dex_vendor_info End_SQL  $sth->execute() or die "Couldn't execute statement: $DBI::errstr; stopped";


Hilbert space of a free particle: Countable or Uncountable?

This is obviously a follow on question to the Phys.SE post   So I thought that the Hilbert space of a bound electron is countable, but the Hilbert space of a free electron is uncountable.  But the arguments about smoothness and delta functions in the answers to the previous question convince me otherwise. Why is the Hilbert space of a free particle not also countable?


How do I unnest a tuple with mixed types?

I'm trying to flatten a tuple with mixed types into a list. The following function does not produce the desired output:   a = (1, 2, 3, ['first', 'second']) def flatten(l):  return flatten(l[0]) + (flatten(l[1:]) if len(l) > 1 else []) if type(l) is list else [l]  >>> flatten(a) [(1, 2, 3, ['first', 'second'])] >>> flatten(flatten(a)) [(1, 2, 3, ['first', 'second'])] >>> [flatten(item) for item in a] [[1], [2], [3], ['first', 'second']]   the output should be:  >>> [1, 2, 3, 'first', 'second']


This is very annoying. I don't want to sound like a drag or anything to you security people but I switched over from windows and everytime I install or do something I need to type a password. Is there anyway to disable this?  (And please don't try to talk me out of it. Its legitly annoying.)  Edit: I'm going back to windows. This is just too annoying. First removing of Gnome and then forcing this garbage. What is this? NSABuntu?


I have a new MacBook Pro 2017, running OS 10.13.6 and I am afraid to shut down because I don't remember my password.  How do I find it or make a new one?


A word for when you just learned a new word and suddenly you notice it everywhere

You're watching TV or something, and you hear a word1 that you've never heard before. You look up the meaning of this word. This new word is suddenly popping up everywhere!   You're now seeing the word on social media People you know are now saying it It suddenly seems like its popping up everywhere but didn't even exist a day ago!    Is there a word for that?    1 "word" - it can be a word or a phrase (etc.)


m trying to write a super simple piece of code which asks "are we nearly there yet" if the user inputs yeah they get the answer "finally" if the user says anything other than yeah the computer keeps asking are we nearly there yet? for some reason when I run the code below even if I type "yeah" after the first prompt the computer just keeps printing are we nearly there yet? and can't get through the loop.     import java.util.Scanner;      class FirstAttempt {      public static void main(String args[]) {          Scanner s= new Scanner(System.in);     String a ="  ";          System.out.println("are we nearly there yet?");     a  = s.next();                  while ( a != "yeah" & a != "Yeah")                 {System.out.println("are we nearly there yet?");            s = new Scanner(System.in);         a = s.nextLine(); }                  System.out.println("finally");              } }


I have a logo on a cream background that I need to delete the cream from so I can make it match the documentit will go on.  In photoshop I would just use the magic wand tool, but I need to know how to do this in illustrator so I can keep it a vector image.


Why does SCP hang on copying files larger than 1405 bytes?

I'm trying to copy a file from one of my local machines to a remote machine. Copying a file with size upto 1405 bytes works fine. When I try to scp a larger file, the file gets copied but the scp process hangs up and doesn't exit. I have to hit Ctrl-C to return back to the shell.  I have observed the same behavior with FTP as well. Any ideas about what might be causing this?


Is it possible to make a file that has full permissions for everybody but is impossible to delete?


Bug in Stack Exchange's "top questions" page

It seems like if Stack Exchange has not registered correctly how many votes my Stack Overflow question has. From my  I see my question to have 7 votes  When if I go to the  it only has 4. Feature or bug?


Why is this javascript expression evaluated to false?

I have written a simple function that nullifies itself after its first call:  var nullify = function(){     nullify = null;     return 1;      };   If I call it two times, like this:  console.log(nullify()); console.log(nullify);   Then the 1st expression will return 1, and the other will evaluate to null. All clear up to this point.  If I however do it in a single expression and wrap it in a function:  var fun = function(f){     return f() && !f; }   Then, for some reason:  console.log(fun(nullify));   evaluates to false, while I would expect it to be true, since 1st operand will return 1 and the other, as a negation of null, true.   The evaluation of the right-hand operand occurs when the nullify functiion has already called nullify = null, is that right? What am I missing?


How can a script add a little icon overlay on files' icons

Just like Dropbox does, I'd like to show if a file is backed up using the icon overlay. How could this be done, without human intervention and regarding a specific computer so it doesn't have to be distributable.  This question regards only how to add/change this icon small overlay, not how to check if the files are backed up.  I am aiming at Windows 7 at the moment.


Why are partial derivatives of a harmonic function also harmonic?

I've tried manipulating some expressions but still can't quite get my head around why the partial derivatives of $u(x,y)$, a harmonic function, are also harmonic.


Displacement current in charging capacitor

In the classic example of a charging capacitor I can see how an Amperian loop with a surface going between the capacitor's plates would feel a changing electric flux, as the electric field between the plates changes with time.  However, considering the same Amperian loop but with a flat surface crossed by the wire leading to the capacitor, there is no displacement current, only conducting current.  The fact that there is no displacement current tell us that there is no change in the electric field across that flat surface.  Can someone elaborate more to me why there is no changing electric field across the flat surface too? I can't understand it...


Wirtinger derivatives and Cauchy integral

Suppose a complex valued function $f$ is of class $C^1$ defined on the disk $|z-z_0|<R,$ and let $C_r$ denote the circle $|z-z_0|=r$ with $0<r<R$. Prove that  $$\lim_{r \to 0}\frac{1}{2\pi i r^2} \oint_{C_r} f(z)\mathrm{d}z={\frac{\partial f}{\partial \bar{z}}(z_0)}.$$ My idea is to estimate $\oint_{C_r} \frac{1}{r^2}f(z)\mathrm{d}z-\oint_{C_r}\frac{\partial f}{\partial \bar{z}}/(z-z_0)dz$ by writting in a parametric form. But I got stuck when I tried to estiamte $f(z)(z-z_0)-r^2\frac{\partial f}{\partial \bar{z}}.$ Can you give me some hints to estimate that quantity? Like can I use talor expansion in polar coordiante?


If $K \leq H \leq G$, show that $[G:K] = [G:H][H:K]$.

This is not for homework. (I am a grader for a class.)  The case in which $G$ is finite is trivial. (That is, use a corollary to Lagrange's Theorem, and set $[G:H] = \dfrac{|G|}{|H|}$, and similarly for $[H:K]$.) How do you prove this for when $G$ is infinite?   The proof of this statement that I know well tries to show that $[G:K]$ is finite iff $[G:H]$ and $[H:K]$ are finite, but I am not a fan of that proof. For pedagogical purposes, I'm looking for a better proof. (The course uses right cosets by convention.)  The course has just started covering normal subgroups, so things like the Isomorphism Theorems are not known yet.


Show "this question has an active bounty and cannot be closed" earlier, when it applies

If a bounty is active on a question, that question . However, attempting to vote to close works just fine until the "Vote to close" button is pressed. Only then does the "this question has an active bounty and cannot be closed" message pop up.  There may be a technical reason for this, but there's no workflow reason for it. Please show the message as soon as the "close" link is clicked.


JK Rowling and women's situation in magical society

In the Harry Potter books, women in the magical cover very important roles, and  are equal to men from this point of view. This emancipation is similar to what has been quite recently achieved in our times (in UK, at least)  What is remarkable is that, when describing ancient magical society, JK Rowling seems to remark that this equality was real also in those times. Even when speaking about a century ago or before, women with powerful roles are cited.  I am also thinking about quidditch, which is the main magical sport and is played by both men and women on equal basis (at Hogwarts, at least).  I tend to believe this is a JK Rowling's specific choice. Are there any sources where she talks about this?


I have seen two ways to wire an event:  <input type="button" onclick=" printGrid() " value="Print" />   $(document).ready(function () {       $("#printGrid").click(function () {         printGrid();     });  });   Is there a difference or benefit for one over the other (besides the fact that the second is using JQuery)?  Note that this question is only about the wireup, not using inline javascript.


I am making a game where i have items or blocks stacked on top of each other.  What i would like to do is, when the first item(or the item at the bottom of the stack) is removed, i would like to shift all the blocks above, down into the next position below it and add another block to the top of the stack.  Sort of like in a match 3 game.   Could someone provide instructions for doing this? or some type of psuedocode?  Thanks guys


The number of divisors of 9600 including 1 and 9600 are??  Is there any other way of doing this rather than manually finding the divisors?


How would you calculate the Tangent without a calculator?

I was just curious as to how you would calculate it without a calculator. I don't care if it's in radians or degrees, but I just would like it to be specified.


Select values that meet different conditions on different rows?

This is a very basic query I can't figure out....  Let's say I have a two column table like this:  userid  |  roleid --------|--------    1    |    1    1    |    2    1    |    3    2    |    1   I want to get all distinct userids that have roleids 1, 2 AND 3.  Using the above example, the only result I want returned is userid 1.  How do I do this?


Number of permutations of AAABBBCCC such that no two A's or B's or C's together


Can't maximise Minecraft after toggling Fullscreen with F11?

I accidently pressed F11 for PC minecraft and now the screen's all messed up.  When I turn Fullscreen OFF, it minimises, but the button to maximise is not working anymore.  How do I reverse it to normal?


Prove an entire function is a constant under an inequality

f is an entire function, suppose $|f(z^{2})| \leq  2|f(z)|$ for all C, then f is a constant. I 'm trying to use Liouville's theorem, but it seems that it isn't helpful.


Exception Handling vs manually checking the condition

I am coding in java since long, However I am confused in Exception Handling. I have to check the valid user.  One way is the if the user is not in db throw no user found exception and then catch the exception and then show the message to the client.  Another way is to check whether the user is in db with if condition and then respond back with message.. Instead of exception  which one is better and why? When to use If and when to catch an exception


Design patterns for effects between actors and technology

I'm working on my first game, and taking the opportunity to brush up my C++ (I want to make as much of it as portable as I can.)  Whilst working on the technology tree and how it affects actors (spaceships, planets, crew, buildings, etc) I can't find a pattern that decouples these entities enough to feel like a clean approach.  Just as an idea, here's the type of effects these actors can have on one another (and techs too)   An engineer inside a spaceship boosts its shield A hero in a spaceship in a fleet increases morale A technology improves spaceships' travel distance A building in a planet improves its production   The best I can come up with is the Observer pattern, and basically manage it more or less manually (when a crew member enters a spaceship, fire the event; when a new building is built in a planet, fire the event, etc etc.) but it seems to be too tightly coupled to me.  I would love to get some ideas about how to approach this better.


Is it possible to SCP from a remote to local whilst logged into the remote and without knowing the local's IP address?

I regularly find myself wanting to copy a file from remote terminal session to my local machine. Usually I log out of the remote session and call an scp transfer from local to copy the file from remote to local. But this feels a little long winded. I would like to transfer the file whilst logged into the remote over SSH to save time. My local machine is connected to the internet from a dynamic IP range so I'm never quite sure how to connect to it remotely. But surely, as the remote session originates from my laptop, there must be a shortcut in scp to get back to my laptop... Right?


Error: Illegal parameter number in definition of \reserved@a

When I am using \caption{$\E_\A(D)$ where $\ora{UF}\!_n$} inside a table environment there shows some errors.  Error :   Only one # is allowed per tab. ...crcr }}}_n$\relax }}{95}{table.caption.41}   Error :   Illegal parameter number in definition of \reserved@a. \caption{$\E_\A(D)$ where $\ora{UF}\!_n$}   Here \E stands for \mathscr{E}, \A stands for \text{\k{A}}, \ora for \overrightarrow.  Please help resolving this problem.


Why does exclamation mark within double quotes cause a Bash error?

Please look at these commands:  $ notify-send SYNC TIME! $ notify-send 'SYNC TIME!' $ notify-send "SYNC TIME!" bash: !": event not found $   The first two commands produce a notification bubble as expected. The third gives the error shown.  and  $ echo SYNC TIME! SYNC TIME! $ echo 'SYNC TIME!' SYNC TIME! $ echo "SYNC TIME!" bash: !": event not found $   Here as well, the echo works for first two commands but not in the third.  More problems here (although I was not planning on using this): both notify-send "SYNC!TIME" and echo "SYNC!TIME" give bash: !TIME": event not found.  But both notify-send and echo work with "SYNC! TIME"  Can someone please explain why the bash: !": event not found error appears?


What is the difference or value of these block coding styles in Ruby?

Which style is preferred? Is there a good reason for one vs. the other?  Thanks in advance!  1) cmds.each do |cmd|    end  2) cmds.each { |cmd|    }   Example code:  cmds = [ "create", "update", "list", "help" ]  # Block style one # cmds.each do |cmd|   puts "loop1, cmd: #{cmd}" end  # Block style two # cmds.each { |cmd|   puts "loop2, cmd: #{cmd}" }


Solving an equation over the reals: $ x^3 + 1 = 2\sqrt[3]{{2x - 1}}$

Solve the following equation over the reals:$$ x^3  + 1 = 2\sqrt[3]{{2x - 1}} $$ I noticed that 1 is a trivial solution, then I tried raising the equation to the 3rd, then dividing the polynomial by $(x-1)$.. But I can't see the solution, how do I go from here?


How do I put a stencil-like texture across a sectioned object?

I have a rough wood board crate I want to apply (UV map) a stencil on, but only on one side of the face AND I want it to disappear in between the boards --just like the attached example image (created in Photoshop). Any suggestions?    UPDATE: Secondary Problem in attempting the 2nd answer below: Following the answer below I could duplicate the nodes as outlined to get the decal on the bars however it still wraps around the edge of the bars and does not show just on the one side as I want it too. What am I doing wrong? (Please note: there is a follow up to this in the 2nd answer below) As you can see I applied the answer / solution  on test bars until I can figure out how to move that to the main wood shelf object's middle section.     UPDATE 2: For a 3rd very good answer please refer to this link


Advantages of creating Python Toolbox over Custom Toolbox?

I enjoy making different geoprocessing tools to practice Python and to become more familiar with the arcpy modules. I've just been using a Custom Toolbox and then importing the Python script and setting the parameters, but I'm wondering if I should be using a Python Toolbox instead.  Are there any distinct advantages of one Toolbox over the other?


Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?

I'm curious as to whether or not there is a real difference between the money datatype and something like decimal(19,4) (which is what money uses internally, I believe).  I'm aware that money is specific to SQL Server. I want to know if there is a compelling reason to choose one over the other; most SQL Server samples (e.g. the AdventureWorks database) use money and not decimal for things like price information.    Should I just continue to use the money datatype, or is there a benefit to using decimal instead? Money is fewer characters to type, but that's not a valid reason :)


I have Ubuntu downloaded on a usb and when I start it up, I cannot get my wifi to turn on. I have already been to system settings to try to turn on the Broadcom but it just stays on do not use selection after applying.


A reference which justifies "The use of Philosophy"

Recently I've got into an argument with a friend of mine about a cliché, "What is the use of philosophy?". Well we didn't discuss it that much but I want to keep the argument based on some philosopher's reasoning rather than my own.  I actually really like the introduction of "History of Western Philosophy by Russell:     “ Science tells us what we can know, but what we can know is little,   and if we forget how much we cannot know we become insensitive to many   things of very great importance. Theology, on the other hand, induces   a dogmatic belief that we have knowledge where in fact we have   ignorance, and by doing so generates a kind of impertinent insolence   towards the universe. Uncertainty, in the presence of vivid hopes and   fears, is painful, but must be endured if we wish to live without the   support of comforting fairy tales. It is not good either to forget the   questions that philosophy asks, or to persuade ourselves that we have   found indubitable answers to them. To teach how to live without   certainty, and yet without being paralyzed by hesitation, is perhaps   the chief thing that philosophy, in our age, can still do for those   who study it.”   But I thought considering the fact that the book has been written in 1945, there might be better and more up to date counter-arguments against this question and maybe even more elaborated ones. I have already browsed , but answers there are either personal opinions (which as I said, I am looking for a reference) or improper from my point of view; Take Delouse's answer; he basically insults the person who asks such a question. I'd rather prefer a more disinterested argument as Russel's.  I am not asking for a book on the subject. But maybe a book that discusses the topic as part of its objective, like Russel's. Does anybody know any reference for it?


Is there a closed formula for the sum $q+q^2+q^4+\dots+q^{2^n}$?

I was trying to create closed formulas for certain iterated sequences, and came across this sum: $$A := \sum_{k=0}^n q^{2^k} = q+q^2+q^4+\dots+q^{2^n}, \quad q\in\Bbb{R},n\in\Bbb{N}^+$$ I'm trying to find a closed formula for this expression, or a formula where you can obtain the value of the sum by using much fewer arithmetic operations.  I know that the sum  $$S := \sum_{k=0}^n q^k = 1+q+q^2+\dots+q^n$$  has a closed form, since  $$\begin{align} S &= 1+q+q^2+\dots+q^n \\ qS &= q+q^2+q^3+\dots+q^{n+1} \\ qS-S &= q^{n+1}-1 \\ (q-1)S &= q^{n+1}-1 \\ S &= \begin{cases} \frac{q^n-1}{q-1} \quad \text{ if } q \ne 1\\[2ex] n+1 \quad \text{ if } q = 1\end{cases} \end{align}$$  But when trying to use a similar method to determine the value of $A$, we just get a tautology:  $$\begin{align}A = q+q^2+q^4+\dots+q^{2^n}\end{align}$$  Multiplying with $q^c$ won't result in any sort of simplification, so it makes the most sense, to square both sides:  $$\begin{align} A^2 &= \begin{matrix}q^2+q^4+q^8+\dots+q^{2^{n+1}} + q(q^2+q^3+\dots+q^{2^n}) + \\ + q^2(q+q^3+\dots+q^{2^n})+\dots+q^{2^n}(1+q+\dots+q^{2^{n-1}})\end{matrix} \\ A^2 &= A-q+q^{2^{n+1}}+q(A-q)+q^2(A-q^2)+\dots+q^{2^n}(A-q^{2^n}) \\ A^2 &= A-q+q^{2^{n+1}}+qA-q^2+q^2A-q^4+\dots+q^{2^n}A-q^{2^{n+1}} \\ A^2 &= A-q+q^{2^{n+1}}+A(q+q^2+\dots+q^{2^n})-(q^2+q^4+\dots+q^{2^{n+1}}) \\ A^2 &= A-q+q^{2^{n+1}}+A^2-(A-q+q^{2^{n+1}}) \\ A^2 &= A^2 \dots \end{align}$$  I also tried writing up $A$ in the $q$-number system, such that:  $$A = \left(\stackrel{q^{2^n}}{1}\ \underbrace{00\dots 0}_{n-1}\ \stackrel{q^{2^{n-1}}}{1}\ \underbrace{00\dots 0}_{n-2}\ \stackrel{q^{2^{n-2}}}{1} \ \dots \ \stackrel{q^{2^2}}{1}\underbrace{\stackrel{q^3}{0}}_{1}\stackrel{q^{2^1}}{1}\stackrel{q^{2^0}}{1}\stackrel{q^0}{0}\right)_{q}$$  And tried to use formulas to fill up the $0$'s, and relate $A$ to $(11\dots 1)_{q}$, but I just got even more complicated equations that would be more difficult to write up in a closed formula than $A$.  I'm doubtful of there being such a formula, but maybe we can actually obtain one using a different approach.  WolframAlpha also couldn't simplify it, however, that still doesn't mean that such a closed formula doesn't exist.  I'm aware of the trick that  $$A = q+q^2+q^4+\dots+q^{2^n} = q(1+q(1+q^2(1+q^4(1+\dots(1+q^{2^{n-1}})\dots),$$  which involves fewer arithmetic operations to calculate, however I'm only satisfied with a closed formula if it doesn't include dots and/or sum/product/etc. notations. If you could help me find one or show that it doesn't exist using our basic arithmetic notations, that'd be highly appreciated! Thank you in advance.


Is there a way to access wifi in Zurich airport without a phone service?

I am traveling through Zurich and have a phone without any roaming there; I'm planning on picking up a SIM once I get to my final destination. Last time I was there, I couldn't access the airport wifi because it required a code sent via SMS.    In the event I need to contact someone or coordinate about flight delays, is there some alternate way to get wifi access?


Can I access my Android through ADB if the phone can only get to the fastboot menu?

I would like to recover message attachments from a Pixel 3 that died recently. (Yes, I should have had them saved and backed up, but I missed that option for message attachments.)  However, the phone is minimally functional. If the phone could turn on, I could sync those files and be done. It also appears that I need to turn the phone on to enable usb debugging for ADB. I can reach the fastboot menu by holding the power and volume down buttons, but if I try to go past that into "Start" or "Recovery Mode" or even "Rescue Mode," the phone powers off again.  While in the fastboot menu, I can see that a Pixel 3 device is connected by usb to my computer. I have installed Android Studio, Android SDK, and the Google USB drivers. The phone appeared as "LeMobile Android Device" at first, but after changing the driver to Google's it is now "Android Device"--"Android Bootloader Interface."  Running adb devices returns an empty list even while Device Manager shows it is attached (probably because I can't turn the phone on and enable usb debugging).  I'm out of ideas, and am looking for ADB tips to try. What can I try next? How can I get the phone to start or to get access to the phone without leaving the fastboot menu?  Thanks.


"Your flagging history" is broken when a user has only raised helpful spam flags

Take a look at this:    The "Your flagging history" summary is gone! On a site where I have more flags...    This is fine. It seems that whenever the first section has no data to show, nothing shows.


Where did the jet engine come from in the movie Donnie Darko?

In the film Donnie Darko, a jet engine lands on Donnie's room in the beginning of the movie. I thought that it was the engine of the plane in which his mother and sister were travelling, which gets crashed and was sent from the future by Donnie through the portal as an act of self sacrifice to save others. If this was the case, he had successfully altered the future and the crash should not have happened in the future. If the crash itself had not taken place, how did he send the engine? Or did he transfer that object from tangent universe to the primary universe (I think this is highly unlikely).


How do I make the photo brighter in manual mode?  When I prepare to take a photo in manual mode it is very hard to see the subject after I take the photo it is all black. Indoor and outdoor


How to know if one is suitable for pursuing academia or Research work their entire life?

I am a PhD student in engineering in an university in Canada. I am close to completion of my thesis but I am not very proud of my work. I have couple of publications from my work, all in decent journals. I feel that I have not utilized the opportunities available to me and wasted time in personal activities that did nothing to my CV.   Owing to my inadequate performance during PhD. I am constantly regretting my decision of pursuing higher studies. I was never a star student. My undergrad was from a very low ranking school where I had received very average grades. However, I somehow got into the top graduate school where too I struggled in getting average grades. My research there was very unimpressive and not a single professor urged me to pursue PhD. My master's advisor even expressed shock when I had asked for his recommendation for applying to PhD school.  However, luck struck again, and I got into a reputed PhD program. My advisor has had a lot of patience with me. She is a hands off kind of person, but she has never complained about my performance till date. Now as I am completing my thesis, I am confused about my future career trajectory.  I feel like I do not belong to academia or research industry as I don't possess the necessary skills (sound technical skills, exceptional analytical skills and focus). I feel like a failure who is in a wrong profession. I really don't know what to do now.  My only reason for pursuing PhD in my current field of study was that I loved the process of researching. I loved finding reason behind why a physical phenomenon occurs. But, I now feel that just love for research is not an adequate reason for doing PhD or master's degree.  In short; I have realized that I am not not suitable for academia or research industry as I don't possess the necessary skills for pursuing research. I should have taken the engineering job after my undergrad as I was never built for a life in research.


How to Add a Shader to a Specific Part/Area of an Object?

So let's say I create a material in Cycles and let's say, I load an image texture onto a sword. It perfectly fits, all good.  Now, the sword I would load in would only be one part, it's just one big mesh.  So how would I select an area of the sword, let's say one part would be steel, and the other part would be (leather)? I just need to know how to add more than one shader on different parts of the object.


How to use SVD for dimensionality reduction

After reading several "tutorials" on SVD I am left still wondering how to use it for dimensionality reduction.  Here is my confusion in an applied setting. If I limit svd to only considering the first two singular values / vectors and "recreate" the matrix, the dimensionality is still the same (4 columns). What should be done here to instead only use 2 columns?  data(iris) s<-svd(iris[,-5])  u<-as.matrix(s$u[,1:2])     v<-as.matrix(s$v[,1:2]) d<-as.matrix(diag(sing$d)[1:2, 1:2])  s2<-u%*%d%*%t(v)


How save Xrandr orientation change settings

Hello When I turn on my Lap Top the screen rotated 90 deg. (Both of login screen and desktop screen). So I use this code to rotate screen  xrandr -o normal   but the first problem is: this code is just for desktop (I need to login to computer and run this code and I can not change login screen rotation) and the second problem is: this code is temporary and I want save setting after restart  My lap top is: Asus Tp 550 LJ and has  touchscreen


I've seen many LaTeX Code Snippets like this one   \AddToShipoutPictureBG{%     \AtPageUpperLeft{%         {\color{red}%             \rule[-1cm]%offset PageBorder                 {\paperwidth}%{14.8cm}                 {1cm}%height         }%     }% }   where  most line endings - if not all - are escaped with %. I don't understand the reason, as % marks (per definition) text, which will not interpreted by the compiler. So What is the reason, people escape their line endings?


This question is asked on Dec 2014, 4 months ago? (Today is May 2015)

The question is  in Academia.    In my calculate, it's almost 5 months, so when rounding it, should the number be rounded to 5?  Suggest feature/discussion: instead of rounding down, should we round it to the closest number?


By adding use-ajax to a link we can open a modal using the Drupal ajax library as per the . E.g. <a class="use-ajax"      data-dialog-options="{&quot;width&quot;:400}"      data-dialog-type="modal"      href="/node/1">     First article displayed in modal dialog. </a>  This will use the ajax library to fetch node/1 and then display it in a modal. There is also a  which allows opening modals using JavaScript. E.g. var myDialog  = Drupal.dialog(ADOMElement, settings); myDialog.show();  The problem with this API is you need to pass in a existing DOM element. My question is can I trigger opening a modal with JavaScript and utalise the internal Drupal ajax library to actually fetch the content? E.g Can I do something like this? var myDialog  = Drupal.dialog('/node/1', {useAjax: true}); myDialog.show();  I could just create an html link as per my first code block, hide it with css, and then trigger a click on it with JS but this seems a bit hacky - there must be a way to trigger this action using pure JS.


jquery event on dynmically created table row

I have a code which has buttons to add and delete rows. I want to change the background as soon as mouse enters the table and back to normal when it leaves the table. I checked all the solutions on stackoverflow nothing is working for me.    Here is my html code for the table:

  First Name	  Last name	  Email	  Telephone

 <input type='text' name='first_name'>	 <input type='text' name='last_name'>	 <input type='text' name='email'>	 <input type='text' name='telephone'>	   <input type="button" value="Delete" class="delete"  onclick="delete_row('1')">

 <input type='text' name='first_name'>	 <input type='text' name='last_name'>	  <input type='text' name='email'>	 <input type='text' name='telephone'>	   <input type="button" value="Delete" class="delete"  onclick="delete_row('2')">

 <input type='text' name='first_name'>	 <input type='text' name='last_name'>	 <input type='text' name='email'>	 <input type='text' name='telephone'>	   <input type="button" value="Delete" class="delete"  onclick="delete_row('3')">

 <input type="text" id="new_fname">	 <input type="text" id="new_lname">	 <input type="text" id="new_email">	 <input type="text" id="new_telephone">	 <input type="button" class="add" onclick="add_row();" value="Add Row"  style="float:center;">

      And here is my script code:   $(document).ready(function()  {    $(".wrapper").on("mouseenter","td", function() {     $("input[type=text]").css("background-color", "lightblue");     }).on("mouseleave","td", function() {          $("input[type=text]").css("background-color", "");          });   });  function delete_row(no) {  document.getElementById("row"+no+"").outerHTML=""; };  function add_row() {  var new_fname=document.getElementById("new_fname").value;  var new_lname=document.getElementById("new_lname").value;  var new_email=document.getElementById("new_email").value;  var new_telephone=document.getElementById("new_telephone").value;    var table=document.getElementById("data_table");  var table_len=(table.rows.length)-1;  var row = table.insertRow(table_len).outerHTML="
  "+new_fname+"<input type='text'   name='first_name'>	"+new_lname+"<input   type='text' name='last_name'>	"+new_email+"<input type='text' name='email'>  	"+new_telephone+"<input   type='text' name='telephone'>	<input type='button' value='Delete'   class='delete' onclick='delete_row("+table_len+")'>
";   document.getElementById("new_fname").value="";  document.getElementById("new_lname").value="";  document.getElementById("new_email").value="";  document.getElementById("new_telephone").value=""; };   And thank you


Child meta sites mistakenly suggest user to acquire a badge which isn't avalable on that site

Check the following screenshot from CS meta:    It says,      Take the tour and earn your first badge   Clicking the button redirects to the tour page of the main site and scrolling it doesn't change anything in the meta. Which is obvious as the badge informed doesn't exist on meta, unlike the main SE sites. However, this phenomenon is true for other sites as well. Is it a developer oversight?


Suggest the best way to take photos of flying birds

I am an amateur photographer and I have a Sony DSC HX400v bridge camera which has 50x optical zoom (quite helpful in taking close-up shots of wild animals). The effectiveness of the zoom lens is however negated when I try to focus on a swiftly moving subject such as an eagle or any other bird in flight. I also have a tripod with me. Can anyone please suggest ways/provide tips to capture a flying bird accurately?  Thanks in advance


Error BrokenCount > 0  Details refer to lib6 dependencies I had attempted to up grade from 12.04 to 14.04 but the upgrade package advised me not to because my graphics hardware might not be good enough. After I didn't continue the system upgrade, the Broken package message appears in Update Manager.


Is there a word to describe indecisiveness between two things?

Possible Duplicate:          Is there a word to describe indecisiveness, specifically between two things? I tried online dictionaries, but did not find anything.


Imagine that we could weigh antimatter on a scale. Would it have a negative or positive weight. EDIT: I see a similar question, but it dates from 2014. It mentions some experiments to be carried out. Any conclusive stuff?


Difference between various methods for producing text in math mode

What is the difference between \text, \textrm, \textnormal, and \mbox (and possibly other commands commonly used to produce text in math mode)?  Various (La)TeX tutorials teach different methods, and I am sure that there is either a best one or there are subtly different usage scenarios.


We define the relationship between the two sets $S_1≡S_2$ if and only if $|S_1|=|S_2|$.  How to show that $≡$ is an equivalence relation ?  sorry I'm from Iran and Basic my English is poor.


I was just wondering if they was an option for line correction on photoshop. In clip studio plant there is an option which is called post correction which can be adjust to make the lines actually straight. I am new in photoshop so I am not sure if there is a similar option like in Clip studio paint. Please let me know if anyone knows.


"Use Option as Meta key" with ability to type the # symbol

I am using Terminal version 2.5, where I have two requirements:  I need to be able to type the Meta key. I need to be able to type the # character, too (Option+3 for the UK keyboard layout)  How can I satisfy both of these? By default, (2) is satisfied, but (1) is not. I can then turn on "Use Option as Meta key", which satisfies (1), but breaks requirement (2). How can I have both? (It shouldn't be so hard for me to just be able to type.) Edit: what I'm looking for, for example, might be a way to just "Use Option as Meta key" for the left/right Option key, or a way to override the "Use Option as Meta key" for the sole exception of the # character.


If I missed my flight to Moscow in Amsterdam (Transit), can I book again while in transit to Moscow with transit in Copenhagen, Denmark? Thank you


Undefined reference error for template method

This has been driving me mad for the past hour and a half. I know it's a small thing but cannot find what's wrong (the fact that it's a rainy Friday afternoon, of course, does not help).  I have defined the following class that will hold configuration parameters read from a file and will let me access them from my program:  class VAConfig {     friend std::ostream& operator<<( std::ostream& lhs, const VAConfig& rhs);  private:     VAConfig();     static std::string      configFilename;     static VAConfig*        pConfigInstance;     static TiXmlDocument*   pXmlDoc;     std::map<std::string, std::string> valueHash;  public:     static VAConfig* getInstance();     static void setConfigFileName( std::string& filename ) { configFilename = filename; }     virtual ~VAConfig();      void readParameterSet( std::string parameterGroupName );     template<typename T> T readParameter( const std::string parameterName );     template<typename T> T convert( const std::string& value ); };   where the method convert() is defined in VAConfig.cpp as  template <typename T> T VAConfig::convert( const std::string& value ) {     T t;     std::istringstream iss( value, std::istringstream::in );     iss >> t;     return t; }   All quite simple. But when I test from my main program using  int y = parameters->convert<int>("5");   I get an undefined reference to 'int VAConfig::convert<int>...' compilation error. Ditto for readParameter().  Looked at a lot of template tutorials but coul not figure this out. Any ideas?


Why is ANOVA equivalent to linear regression?

I read that ANOVA and linear regression are the same thing. How can that be, considering that the output of ANOVA is some $F$ value and some $p$-value based on which you conclude if the sample means across the different samples are same or different.  But assuming the means are not equal (reject null hypothesis), ANOVA tells you nothing about the coefficients of the linear model. So how is linear regression the same as ANOVA?


How to prove this one? Let $f: R \longrightarrow S$ be a homomorphism of rings $R$ and $S$. If $M$ is a maximal ideal of $S$, then $f^{-1}(M)$ is a maximal iseal of $R$.


I am trying to propagate an array along a curve. The mesh that is being replicated as an array is an iconosphere. Attached is an image of the array and the curve. You can see that almost all the iconospheres are distended to various degrees. There are probably just 2 that are uniform in size. I am guessing the distortion is due to the intricate curve and number of vertices along the path. Is there anyway around this?


I have a little problem with a script of mine. I execute a command in background using sudo and I try to retrieve the PID of the command in a variable.  the code is the following:  #!/bin/bash  sudo badblocks -o $2 $1 &   PROCESSID=$(pgrep -P $!)  echo $PROCESSID   I executed every command one by one in a shell and it works fine but when i launch the script it doesn't work. I've other command to obtain the PID such as "ps --ppid $! -o pid=" but it doesn't work either.  if you have any idea why?


Is there a possibility for Iterm to always be on top?  I have seen some issues but don't know whether it's already implemented.


Book that starts with humanity narrowly escaping the death of the sun consuming the Earth

The book starts with humanity narrowly escaping the death of the sun consuming the Earth. All the humans are only allowed to bring few possessions with them so a little girl brings a notebook and starts a diary about the adventure.  Then they get to a planet with glass-like wheat and build huts and stuff. A large rock formation turns out to be eggs for an alien species and they hatch. By the end of the book the aliens come back to lay their eggs and many drown and the villagers forget all their stories and legends so they read the little girl's diary.


Even-spaced (two) columns in reference page using bibtex - automatically

I have a document I keep compiling, using latex and bibtex, and it automatically creates my reference page. My final page is references and I use two columns, so naturally, assuming the reference page is not full, I get a full left column and a less-than-full right column.  I need the reference page to be evenly spaced between the columns. I usually do the following: After compiling, I edit the .bbl file and insert \vfill\pagebreak after the 'middle' reference. The problem is that after each compilation I need to re-do this.  I'm sorry not to have an MWE but it would require uploading a complete library of references...   Appreciate any comments. Thanks, Ido.


"I want to come there" or "I want to go there"

When someone is away from you and wants to be where you are, do they tell you I want to come there or I want to go there?


Let $A$ be a bounded, nonnegative operator on a complex Hilbert space $H$. Prove that the spectrum $$\sigma(A)\subset[0,+\infty].$$ We say that an operator $A$ is nonnegative if it is self adjoint and  $$ \langle Au,u\rangle \geq 0 \ \ \  \forall u \in H.$$ It is exercise 9.5 page 240 from .  A more general question, there is a theorem that for a self-adjoint operator $$ \sigma(A)\subset\left[-\|A\|,\|A\|\,\right],$$ but is it true that  $$ \sigma(A)\subset[\underset{\|u\|=1}{\inf}\langle Au,u\rangle,\underset{\|u\|=1}{\sup}\langle Au,u\rangle ]?$$


I often use Cycles' built in Glass BSDF shader to achieve realistic refraction effects, but in many cases, it seems that Cycles' glass caustics creates an unfortunately large number of fireflies (pixels that are abnormally bright relative to their surroundings). In some models of mine, even when I render for 3000 or more samples/pixel, my final image is still covered in fireflies. While I can improve this in many cases by increasing the total amount of light available in the scene, this loses a lot of the potency of the refractive effects I'm looking for, especially in scenes with low light levels.  So my question is, how can I reduce the amount of fireflies while using Cycles' caustics without sacrificing the quality of the refractive effects?  Note: I am aware that Cycles' caustics will perform much better once Cycles has full support for bidirectional path-tracing, but it looks unlikely that that will become , unfortunately.


How to install software in terminal in one line and one time?

I want to create a code that I put my terminal to install few software at the same time.  For example, after a fresh install, I like to install this kind of software, but I have to line per line...  I want to do it in one time?   sudo add-apt-repository ppa:atareao/atareao sudo apt-get update sudo apt-get install my-weather-indicator  sudo apt-get install unity-tweak-tool  sudo add-apt-repository ppa:peterlevi/ppa sudo apt-get update sudo apt-get install variety   How I can put all this in the terminal in one shot?   How I can automatically set ENTER when I add the ppa and after set to Yes for the install?


Hamiltonian cycles in associahedron graphs

Let two distinct fully parenthesized products of $n$ symbols be called adjacent provided one of them may be obtained from the other by a single application of the associative law. Such graphs may be viewed as "associahedrons", though my question doesn't involve the graph theory approach so much, and in my case I assume for fixed $n$ that the graph contains as vertices all the parenthesized products. For example, for $n=4$ there are five vertices, each adjacent to $2$ others, and so essentially two possible Hamiltonian cycles. I found that in the case of $n=5$ it was possible to find a Hamiltonian cycle going through all $14$ vertices. (Here I think there are more than one such cycle...)  My question is what happens for larger $n.$ I tried $n=6$ and got close, proceeding by using cycles from previous cases and "sewing them up" into a complete cycle. However I got lost in the details. So I'm curious about the $n=6$ case, and in general for higher $n$ is there a known cutoff beyond which it is known no Hamiltonian cycle exists.  Associahedron reference at Wiki is   Here's the list I found for the $n=5$ case: $$ (((12)3)4)5 \\ ((1(23))4)5 \\ (1((23)4))5 \\ (1(2(34)))5 \\ ((12)(34))5 \\ (12)((34)5) \\ (12)(3(45)) \\ 1(2(3(45))) \\ 1(2((34)5)) \\ 1((2(34))5) \\ 1(((23)4)5) \\ 1((23)(45)) \\ (1(23))(45) \\ ((12)3)(45)  $$  Each is adjacent to the one below in the sense of one use of associative law, including the final one back to the first, to complete the cycle.


TSQL to get the list of associated users from all databases for SQl server Login

I am looking for tsql query to get all the associated users in all dbs for a login. Tried below SQL, but this is not giving right result set. If I execute this query under the Database context where the user is present, it gives output as if user is present in all DBs. Same query executed under the Database context where the user is absent, gives 0 rows as if user is not present in any of the DBs. exec sp_msforeachdb 'select  ''?'' AS DBName,dp.name as username from sys.database_principals dp join sys.server_principals  srp on dp.sid=srp.sid where srp.name=''domain\account'''  Thanks


I would like to random sort a List<MyObject>. Is it possible ?     I though about another solution, using specific random number: I mean, if I could do something like that : random.next(1, 2, 3, 4, 5, 6)  If this call return 3, I could set the next call random.next(1, 2, 4, 5, 6) without the 3 which could return me anything excepted 3, etc...  Then I could finish to disordered my own List.  Thanks


Is it possible to change the natural order of columns in Postgres?

Is it possible to change the natural order of columns in Postgres 8.1?  I know that you shouldn't rely on column order - it's not essential to what I am doing - I only need it to make some auto-generated stuff come out in a way that is more pleasing, so that the field order matches all the way from pgadmin through the back end and out to the front end.


Differentiability implies continuity - A question about the proof

I have a question, to aid my understanding, about the proof that differentiability implies continutity.$\mathstrut$    Differentiability Definition  When we say a function is differentiable at $x_0$, we mean that the limit:  $$f^{\prime} (x) = \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0}$$ exists.  Continuity Definition  When we say a function is continuous at $x_0$, we mean that: $$\lim_{x\to x_0} f(x) - f(x_0) = 0$$  Theorem: Differentiability implies Continuity: If $f$ is a differentiable function at $x_0$, then it is continuous at $x_0$.  Proof:  Let us suppose that $f$ is differentiable at $x_0$. Then $$ \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0} =  f^{\prime} (x) $$  and hence  $$ \lim_{x\to x_0} f(x) - f(x_0) = \lim_{x\to x_0} \left[ \frac{f(x) - f(x_0)}{x-x_0} \right] \cdot \lim_{x\to x_0} (x-x_0) = 0$$  We have therefore shown that, using the definition of continuous, if the function is differentiable at $x_0$, it must also be continuous.  My Question  The proof seems to execute the following steps:   Assume the function is continuous at $x_0$ Show that, with little algebra, we can change this into an equivalent question about differentiability at $x_0$. With this little bit of algebra, we can show that if a function is differentiable at $x_0$ it is also continuous.   What I am slightly unsure about is the apparent circularity. In my mind it seems to say, if a function is continuous, we can show that if it is also differentiable, then it is continuous. Rather than what I was expecting, namely, if a function is differentiable, we can show it must be continuous.  Hopefully my confusion is clear. Any help will be greatly appreciated.


Pingdom error: "No delegation could be found at the parent" when analyzing subdomain

I have a subdomain dramarsarin.crimsonandcyan.com which i wanted to point to another server. I added an A record in the zone file for crimsonandcyan.com with the host 'dramarsarin' and pointed it to the server's ip address.  Now when i do a dns check on pingdom.com for my subdomain, i get this:  No delegation could be found at the parent, making your zone unreachable from the Internet.   How can i fix this? I do see that sometimes it takes too long to resolve the subdomain. That is why i think the analysis of pingdom.com is pretty valid.


How to make sure whenever User is updated or created a contact is too?

I'm new to salesforce so please don't kill me. I'm working on setting up a communities site with an external facing registration. When a user registers, a contact is automatically created. I'm not sure where the code for this is. I'm just trying to update extra fields automatically when that user is created or if the user information is updated. This is my code I have in the CommunitiesSelfRegController.apxc. A contact is created but most of the fields are empty.  /**  * An apex page controller that supports self registration of users in communities that allow self registration  */ public class CommunitiesSelfRegController {               public String firstName {get; set;}     public String lastName {get; set;}     public String email {get; set;}     public String password {get; set {password = value == null ? value : value.trim(); } }     public String confirmPassword {get; set { confirmPassword = value == null ? value : value.trim(); } }     public String communityNickname {get; set { communityNickname = value == null ? value : value.trim(); } }               public CommunitiesSelfRegController() {         String expid = ApexPages.currentPage().getParameters().get('expid');                     if (expId != null) {             Site.setExperienceId(expId);          }         }          private boolean isValidPassword() {         return password == confirmPassword;     }      public PageReference registerUser() {                 // it's okay if password is null - we'll send the user a random password in that case         if (!isValidPassword()) {             ApexPages.Message msg = new ApexPages.Message(ApexPages.Severity.ERROR, Label.site.passwords_dont_match);             ApexPages.addMessage(msg);             return null;         }              String profileId = null; // To be filled in by customer.         String roleEnum = null; // To be filled in by customer.         String accountId = ''; // To be filled in by customer.         String userName = email;                          User u = new User();         u.Username = userName;         u.Email = email;         u.FirstName = firstName;         u.LastName = lastName;         u.CommunityNickname = communityNickname;         u.ProfileId = profileId;                                                     String userId;                  try {             userId = Site.createExternalUser(u, accountId, password);         } catch(Site.ExternalUserCreateException ex) {             List<String> errors = ex.getDisplayMessages();             for (String error : errors)  {                 ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, error));             }                          // This message is used for debugging. Do not display this in the UI to the end user.             // It has the information around why the user creation failed.             System.debug(ex.getMessage());         }                           //I ADDED THIS          try{                          Contact c = new Contact();             c.FirstName = u.FirstName;             c.LastName = u.LastName;             c.Verified__c = false;             c.Username__c = userName;             c.AlternateEmail1__c = communityNickname;             c.Citizenship__c = u.Citizenship__c;             c.Organization__c = u.Organization__C;              c.Company__c = u.Organization__C;                          insert c;             update c;                      } catch (DmlException e){             System.debug('A DML exception has occured: ' +                         e.getMessage());                      }                       //Authentification         if (userId != null) {              if (password != null && password.length() > 1) {                 return Site.login(userName, password, ApexPages.currentPage().getParameters().get('startURL'));             }             else {                 PageReference page = System.Page.CommunitiesSelfRegConfirm;                 page.setRedirect(true);                 return page;             }         }                  return null;     } }


I have a .xal document which can be opened with notepad just fine. Below is the part of it that is important to me:     ...   magV=1   invert=0   text=01000000237843141114052693183714        [Pri1]   enabled=0   ...   I would like to create a script, which would auto replace part of text 140526 in line 128 (it is some old date - 26.05.2014) and replace it with the current date. For example: today it should be 160816, tommorrow there should be 160817, etc.  As said before text is in line 128, characters are from 24 to 30.  If searched around (SED for WIN, VBA, Powershell,...) but i didn't find anything that could work.  Thank you all in advance!


simple, energy efficient circuit to make single IR LED blink

I'm using a 850nm IR LED (), and in order to extend my battery life, I'd like to make the LED blink (UF 1.9 V, IF 100 mA).   I found a couple of links , ,  but they either a) require two LEDs that blink in alternation, or a bunch of resistors that will most probably just drain my battery even quicker (will they?).  Therefore my question:  What's the    most simple energy efficient  smallest possible (ideally not bigger than the battery & LED) ideally operated with 3V or less.   circuit to make an IR LED blink?  EDIT:   I'd like to blink the LED 10 to 30 times per second. But We can start with 2 to 5 times. the LED should be on for 10ms (at least) or 100ms (at most). Depending on blinking frequency. I'm trying to make the circuit as small as possible (size and complexity) cause I wanna use it for a tracking device. I'm powering the LED with a 3V CR2032 battery and I was hoping I could extend the battery life by making the LED blink instead of having it on all the time. I can currently run the IR LED with the CR2032 battery for 4 hours. Extending that time to 8 or maybe even 12 hours would be great.


So I have 2 processing units, one runs on Python and the other runs of C++. The first one will generate a set of data of around 3 - 5 values, either as a list of ints or a string. I want this value to be passed to C++, what is the best method? Like do I have to create a file in python then load it in C++? or there are an another way? This process would repeat every second， so I wish the transmission to be fast enough.


How to find whether root means square error (RMSE) value obtained is good or bad?

I have a dataset having values ranges from 200 to 300. After the data are processed by an algorithm (output will be correlated to input), RMSE is calculated between the input values and the output values obtained from the algorithm. The RMSE value obtained is 23.33. How can I say/find the RMSE value obtained is good or high? Is the RMSE result has a relation with the amplitude of the data?


I'm new to PDO, and I was wondering if my code is safe from SQL Injection, and if there's something I can improve to make it safer or even cleaner.  $statement = $pdo->prepare("INSERT INTO login_users (username, user_level, name, email, password, expires)         VALUES(:username, :user_level, :name, :email, :password, :expires)");     $statement->execute(array(         "username" => $_POST['username'],         "user_level" => $_POST['user_level'],         "name" => $_POST['name'],         "email" => $_POST['email'],         "password" => $_POST['val-password'],         "expires" => $_POST['expires'] . ' ' . $_POST['default-hours']     ));


I am new to Ubuntu, recently I installed it on my desktop (Lenovo), which was previously loaded with Windows. After trying it and comparing it with the previous OS, I definitely do not want to get back to Windows. I would also like to install it on my laptop Lenovo V330-14IKB, but surfing the web I found many commentaries reporting problems with Lenovo. Is it safe to install Ubuntu 20.04 on this laptop?


Convergence in probability and almost surely

Let $X_n$ be a sequence of independent random variable which converges in probability to $X$. Prove $X$ is a constant.  Can someone give me a hint how I should go about proving this? I tried proving this by contradiction by saying $X$ taking 2 different values, but this can still still happen because $X$ is only almost surely constant.


Increase word space between words in small caps

With tracking activated for small caps, it can be a little bit hard to detect interword spaces. Cf. below.  \documentclass{article} \usepackage{fontspec}     \setmainfont{Libertine Serif}[         SmallCapsFeatures = {Letters = SmallCaps, LetterSpace = 5}] \begin{document} The title of my article is \textsc{This is the moment your life changed forever}. \end{document}     I'd like to increase the space between words in small caps, therefore, but only when words on either side are in small caps (i.e. there should be no extra space before the first word written in small caps or after the last word).  I would've thought I could do this by adding WordSpace = <> to SmallCapsFeatures, but this will change the interword space everywhere.  \documentclass{article} \usepackage{fontspec}     \setmainfont{Libertine Serif}[         SmallCapsFeatures = {Letters = SmallCaps, LetterSpace = 5, WordSpace = 5}] \begin{document} The title of my article is \textsc{This is the moment your life changed forever}. \end{document}


I have the weird habit of really enjoying Business class flights while not wanting to spend all of my money on flight tickets.  As of now, I have always been using  or  to search for Business class connections from my hometown to an airport  close to my destination, and then book a cheap economy carrier to my destination, or book a cheap economy carrier to a close country in Europe and then take a business class flight to my destination.  For example:  Case 1:   ZRH (Zürich, Switzerland) -> PTY (Panama City, Panama) in Business.  PTY -> BOG (Bogota, Colombia) in Economy.  Case 2:  ZRH (Zürich, Switzerland) -> PRG (Prague, Czech Republic) in Economy.  PRG -> HND (Tokyo, Japan) in Business.  Is there any search engine that lets you search for this kind of combinations without entering manually all the stopover possibilities?  EDIT:  I don't think it's a duplicate, because  is asking for flight options in premium economy when possible, economy when not. I am specifically asking for the possibility to define business for the longer leg, and eco for the shorter, whilst not having to search every stopover destination by hand.


Partitioning the edges of $K_n$ into $\lfloor \frac n6 \rfloor$ planar subgraphs

Why is it impossible to partition the edges in $K_n$ into $\lfloor \frac n6 \rfloor$ planar subgraphs for $n \ge 6$? I'm just stuck at the beginning and can't figure out how to go about this problem.     Thanks in advance for the help!


Should we necessarily express the dimensions of a physical quantity within square brackets?

For example, should we write the dimension of mass, e.g. $\mathrm{kg}$  as $[M]$ or is it enough to write it as $M$?


Windows 10 Factory Reset: risk for Grub and dual boot partitions?

I just have a quick question. If I choose to factory reset my pc. (Lenovo Thinkpad Windows 10). Will Grub2 also be deleted, along with my Linux dual boot?


How do I find the files installed by a particular package? Where is the .deb file to look at?

I have installed pulseaudio-module-bluetooth using apt.  $ type pulseaudio-module-bluetooth bash: type: pulseaudio-module-bluetooth: not found $ which pulseaudio-module-bluetooth $ whereis pulseaudio-module-bluetooth pulseaudio-module-bluetooth:   Clearly, I'm looking for the wrong thing.  The package does not simply install a command that is the same name as the package.  Alright, then.  I want to find out what all commands (or executables) this package installed, and their locations.  The answers to "" tell me how to find the files installed by the package if I have a .deb file.  I'm not installing directly from a .deb file, though.  I'm using apt.  Where is the .deb file that that used?  Is there a copy on my system somewhere that I can query with the commands in the answers to that question?  Where?  If there isn't a local copy on my system, can I get one with apt?  How?  Is there some handy apt (or similar) command that wraps this up for me, so that I do not have to run dpkg-deb directly?  What is it?  Can I find the package's file list entirely on-line, without explicitly downloading any .deb files and before installing anything with apt?  How?


How many colors are needed to color an infinite grid so that no sqaure have the same color in all 4 vertexes?

Suppose on a 2 dimension infinite grid, all nodes, or equivalently, all $(p,q)$ points, where $p, q \in \mathbb Z$, need to be painted with a color.  Is there a way that, given enough kinds of paiting colors, e.g. $n$, all sqaures will have at least 2 colors? i.e we can avoid to have any square that all its 4 vertexes are painted in the same color?  Or... is this impossible?


Raised a flag and the very next moment it was rectified

I raised a flag on a question which was very poorly formatted. But soon after the flag was raised it was edit and nicely formatted. I feel bad about it. What can I do?


I'd like to use a different + symbol in addition to + in math mode, preferably one which is just bolder than the standard one.  I'm currently using \pmb{+} from the amsbsy package, but it's a bit too lean for my taste, and it looks a bit pointy to the ends.   I am aware of \ding{58} from the pifont package, as well as \Plus from bbding, both of which seem to be non-math mode symbols, and look really bad next to math symbols.  Am I missing some other option to produce a bold +, apart from drawing the symbol myself?


I get a "serious errors while checking the disk drives for /boot" error while booting

I have just set up my new system by creating three partitions on a whole hard disk (/boot, /home, swap and /). I saw  article and now I am getting those errors and the system provide me with some options: (I to ignore, S to skip mounting or M for manual recovery).   I am forced to choose skip mounting because I don't know what manual recovery is. Despite the error I get I think that the system boots okay because I can use the system but this error is very annoying.


how to get shell scripts to run at startup on Yosemite

There is a directory in System/Library for startup items I presume: StartupItems  I need to have a shell script that will configure ethernet interface at start up, with local network address and subnet mask. I need to do this because the network preferences for configuring the ethernet interface will NOT set it using manual settings. THIS appears to be a serious bug, or my installation is bad.  I was given the advice to use  networksetup from the command line but that will not configure the ethernet interface in such a way that the configurations will be there on reboot.  The script needs to do its work with root privileges, or with sudo, but I am assuming that if it uses sudo, there will be a password dialog presented at boot time when the boot process gets to that script.  (I have had enough experience with FreeBsd and Linux to find my way around in the terminal, but not necessarily as it applies to Mac OSX)


Do I need transit visa for Amsterdam Airport?

I am Palestinian with a Lebanese travel document, travelling from India to Bulgaria. I have a visit visa for Bulgaria and the layover in Amsterdam is 5 hours.  Do I need a transit visa?


If $n\ne 4$ is composite, then $n$ divides $(n-1)!$.

I have a proof and need some feedback. It seems really obvious that the statement is true but it is always the obvious ones that are a little trickier to prove. So I would appreciate any feedback. Thank you!  Here is what I am asked to prove:     If $n$ is composite then $(n-1)! \equiv 0 \pmod n$.   Proof:  $n$ is composite $\implies n=ab$ where $a,b \in \mathbb{Z}$ and $0<a,b<n$.  Case 1: If $a=b$ then $n=a^{2}$. Now $n \mid (n-1)! \implies a \mid (n-1)!$, so $$\begin{aligned} (n-1)! &\equiv 1\times 2\times \dotsb \times a \times\dotsb\times (n-a)\times\dotsb\times (n-1) \\ &\equiv 1\times 2\times \dotsb\times a \times\dotsb\times -a\times\dotsb\times -1 \\ &\equiv 0 \pmod n \end{aligned}$$  Case 2: $0<a<b<n$.  Then, since $a \mid n$, $b \mid n$ and $n \mid (n-1)!$ we have that $a \mid (n-1)!$ and $b \mid (n-1)!$.  So this implies $(n-1)! \equiv 1\times 2\times \dotsb\times a \times\dotsb\times b\times\dotsb\times (n-1) \equiv 0 \pmod n$, Q.E.D.


How can I search Outlook, ignoring all emails in a particular folder?

In my case, I need to search for an email from a specific person.  However, this individuals user account is also associated with an auto-email process I have 1,000's of emails from this person, because of this process.  All of these emails are being copied, and marked as read, into a folder that I mostly ignore.  When I attempt to search my email by this user's email address, I see these thousands of emails, and our former conversations are dispersed amongst these emails.  How can I search for this user, ignoring all emails within the folder that is catching all of the auto-emails that are being sent by this users email account?


If $n^c\in\mathbb N$ for every $n\in\mathbb N$, then $c$ is a non-negative integer?

Supposing that a real number $c$ is given, is the following true?  "If $n^c$ is a natural number for every natural number $n$, then $c$ is a non-negative integer."  Though this seems true, I can't prove that. Can anyone help?


Does topological closure operator distribute over set difference?

Consider tw0 sets $A, B$ from the topological space X. Is the following true: $$ \mathbb{cl} (A \setminus B) = \mathbb{cl}\, A  \setminus \mathbb{cl} \,B $$


Any suggestion to make the following c++ code precisely?

Consider the following instructor , I had to initialize treeItem and status anyway , but in a overloaded function , I can introduce the id variable as well.  But it looks silly , I shouldn't be doing this in both of the functions , any suggestions ?  Contact () {     treeItem = NULL;     status = offline; }  Contact (const QString & id) {     treeItem = NULL;     status = offline;      this->id = id; }


How does the scale factor depend on temperature?

So, I'm studying cosmology and my professor often uses the result $a=\frac{T}{T_0}$, but he never derived this relation and he just treates it as something intuitive... I think I can see how this would make sense, but I'd like to get a more formal understanding of it. Any light on this will be much appreciated. Thanks!


Why lambda take a constant value when use for loop?

i need make functions dict with for loop stringlist = ["A", "B", "C"] functions = dict()  for stt in stringlist :    functions[stt] = lambda: stt     functions["A"]()  # result-> # "C" functions["B"]()  # result-> # "C" functions["C"]()  # result-> # "C"


Is it possible to create custom AMPScript Function/Method

Is there any way to create a function or method which takes parameters in AMPScript which can be called anytime? Example would be a simple java function to called multiply (a,b) where the return would be result of a x b. Yes, i know i can multiply in ampscript but i explicitly need it within a function call because i will be calling it multiple times for that email. Thank you.


From command line on macOS, how to add a user group to the Sharing and Permissions list for a directory?

The macOS gui, as shown in the attached image, provides a way to add users and user groups to the permissions of a file system directory.  There are also lots of examples of how to create groups from the command line, etc (dscl, and so forth).  But I don't see anything on how - from the command line - to add user groups to the permissions of a file system directory.    PS: The answers in  covers network shares, but don't show how to do what the Finder does (on an unshared folder).


Proving that every graph that each vertex at degree 2 must contain a cycle

Prove that every graph in which each vertex has degree at least 2 must contain a cycle.  I know that a vertex is a node and the only way for it to have a cycle is that when there are three vertices and three edges and that the shape is of a triangle. However I dont know how to prove it.  Thanks in advance


Finitely generated ideals in a Boolean ring are principal, why?

The classical book on commutative algebra Introduction to Commutative Algebra, by Atiyah and Macdonald, has the following as exercise I.11.       A ring is Boolean if $x^2=x$ for any $x$ of $A$. In a Boolean ring $A$, show that     i) $2x=0$ for all $x\in A$;    ii) Every prime ideal of $A$ is maximal, and its residue field consists of two elements;   iii) Every finitely generated ideal of $A$ is principal.     I can but solve the first two of them; for the last one, I cannot even perceive the situation here, for it will not, generally speaking, be a Dedekind domain, whereof my knowledge is somewhat more. I have hitherto tried to find one element for each ideal of two generators which can stand the stead of them, and then proceed by induction. But even the first step fails to produce any result. Thanks for any hints and inspirations in advance.


Does Ubuntu need an Antivirus?  If so, could you recommend a good one? I am interested on the Ubuntu side only.


Struggling with Null Pointer Exception message when creating an array of objects from separate initialize lists

I have created three initializer arrays that must be used in the 'students' array, which should be an array of student objects. Every time it runs, a NullPointer error appears.   class School {    private Student[] students;    private int size;     public School (int s)    {size = s;}     public void addData()    {       String[] name = {"Tom", "Ann", "Bob", "Jan", "Joe", "Sue", "Jay", "Meg", "Art", "Deb"};       int[] age = {21, 34, 18, 45, 27, 19, 30, 38, 40, 35};       double[] gpa = {1.685, 3.875, 2.5, 4.0, 2.975, 3.225, 3.65, 2.0, 3.999, 2.125};        for(int i = 0; i < size; i++){           students[i] = new Student(name[i], age[i], gpa[i]);         }    }       public String toString()    {        String s = "";        for(int i = 0; i < size; i++){            s = s + students[i].toString();         }         return s;    } }   class Student {    private String name;    private int age;    private double gpa;     public Student (String n, int a, double g)    {       name = n;       age = a;       gpa = g;    }     public String getName() { return name; }      public int getAge()     { return age; }      public double getGPA()  { return gpa; }     public String toString()    {       String temp = name + "  " + age + "  " + gpa + "\n";       return temp;    } }   Where does the problem exactly begin and how would it be resolved?


Why doesn't rain fall down in streams (as opposed to drops)

Why is it that raindrops don't collide and 'stick together' on their descent to Earth, arriving in streams rather than separate drops?


After Brelyna in the College of Winterhold "experimented" on me, I became invisible. Now I am unable to see my character at all. Is this just a glich; is there anything I can do short of starting a new game?


I would love to put the images in logos related to the center of the boxes.    How can I affect this?


$\sqrt{x}=\sqrt{1\cdot x}=\sqrt{(-1)^2\cdot x} = \sqrt{(-1)^2} \cdot \sqrt{x} = (-1) \cdot \sqrt{x}=-\sqrt{x}$  The idea popped into my head while I was evaluating an integral. I have a feeling that I made some obvious mistake because the "proof" is so simple, but I don't see any flaw. Of course, there must be a flaw somewhere. What is it?


If I go to a certain location of my server in creative mode, I instantly die and spawn at my spawn point and then die again repeatedly for 8 more times. Then afterwards when I fly back to where I died I die again repeatedly. I don't die anywhere else except at that location.   I believe this happened because someone set down the command block that keeps killing me. I need help.


Is backpropagation required for optimizing MLPs?

In a neural network (MLP), we can define the error function during training the difference between the target output and the output for the current input. Now we use backpropagation like so:   Calculate the error of the current layer (starting with the output layer going back). Calculate the gradient of the current layer which is the derivative of the total error (from the output layer) derived by the weights of the current layer. Update the weights of the current layer by the gradient multiplied with a learning rate (here we use simple gradient descend). Calculate the gradient of the previous layer which is the derivative of the total error (from the output layer) derived by the weights of the current layer, where we fix the weights of the next layers (which are closer to the output). Update the weights of the current layer by the gradient multiplied with a learning rate (here we use simple gradient descend). ... Continue with 4.   Assuming each layer as N neurons, each layer has N^2 weights. Let's also assume we have L layers, then we have N^2*L weights. With backpropagation, each layer's gradient vector has the size of N^2 entries.  My question in this: The entire MLP is basically a big function containing matrix multiplications and functions of those (like softmax at the end and so on). We are able to calculate the error function by using this function (using relatively simple things like subraction, squaring etc.). This big error function contains the N^2*L weights. I would think we should be able to calculate the gradient of the entire network by deriving it from the error function derived by the N^2*L weights, which would result in a gradient vector of N^2*L entries and update all weights at once with each gradient descend step. Considering that we have far fewer layers than weights per layer, this is a vector space that is not that much larger than the N^2-dimensional gradient vectors that we calculated with backpropagation. So why don't we do this?  I suspect something keeps us from calculating the gradient of the entire MLP - is that so, but what exactly if the MLP is basically a functions which is so well formulated?  (If so, then we could at least use gradient-free optimization methods, and my follow-up questions would be, why we don't and why backpropagation is still so dominant. I read somewhere in the context of Tensorflow, we cannot do without backpropagation, period. But that seems strange to me.)


prove that for an idempotent matrix, trace=rank


In a simple battery + resistor circuit, what form of energy is lost from the electrons upon exiting the resistor?

I will give this question a little context. Firstly, as I understand it, as soon as I "close the switch" on a circuit, electric current pretty quickly establishes a steady state where, at any given cross section along a wire, the average kinetic energy of that slice is both constant and equal anywhere along the wire. (Please correct me if I am misunderstanding).   If the average kinetic energy is constant anywhere throughout the wire in the circuit (which confuses me, as I would think that the electrons should all accelerate after exiting the resistor since they are no longer being impeded as much), that means that the average velocity is constant. So, in the example of a simple circuit with a battery of v Volts and a resistor of o Ohms, my question is the following:  Because a 'voltage drop' is known to occur across the resistor, what type energy is being "traded" to generate the heat that radiates from the resistor? I would think that the reflexive answer is "electrical energy"...hence the VOLTAGE drop (the sacrificed energy is clearly not kinetic, as the velocity is constant everywhere). However, I find this confusing. Does this mean that if I had a positive test charge, it would be easier for me to bring it to the beginning of the resistor as compared to bringing it to the end of the resister?     Further, if the correct answer IS "electrical energy", why exactly DOES electrical energy get "dissipated" as the electrons pass through the resistor? I always here the comment Oh! It's because all the electrons are running into densely packed crap which impedes their flow but that to me sounds like a reason for their KINETIC energy to be reduced. However, clearly that's not the case. So, ultimately, I guess the real question is:  **What goes on in the resistor that is literally removing electrical energy **. I am sure that this is a quantum mechanics question, but my quantum mechanics knowledge is not terribly strong. If I could get an answer that is devoid of crazy wave function equations, I would greatly appreciate it. Thanks!


Upgrading from 19.04 to the next release version

Since 19.04 will only have support til January 2020, how would I upgrade to the next version (19.05 or whatever they label it)? Would I be able to run a terminal command or would I need to reinstall the whole OS from a bootable thumbdrive and save all my data to another storage device first?