Photo distorts terribly on Facebook
Facebook: Ways to preserve image quality of uploaded images?
The following code uses the etoolbox package to convert a list a,b,c into an internal list (called \mylist) and then typesets that with colons: a:b:c:.  However, when I load the etextools package (by uncommenting the second line), I get no list output.   \documentclass{minimal} \usepackage{etoolbox} %\usepackage{etextools} \begin{document} A list: \def\mylist{} \forcsvlist{\listadd\mylist}{a,b,c} \def\do#1{#1:} \dolistloop{\mylist} \end{document}   I suspect it is is a bug since etextools claims to depend on etoolbox.  Is this a bug or am I doing something wrong?  In either case, how can I use \dolistloop with  etextools (which I want for goodies like \expandnext)?  Notes   \show\mylist produces the same output a|b|c| in both cases, so the problem is with \dolistloop which expands to \forlistloop\do The \forlistloop command becomes substantially more complicated when etextools is used.  might be relevant (but not obviously). A Question On Euler's Proof Of the Basel Problem I've studied the proof that Euler gave for the famous , and it would seem that while it is technically correct, he does not justify all of his steps properly. Namely, he assumes that   $$\frac{\sin(x)}{x}=\left(1-\frac{x}{\pi}\right)\left(1+\frac{x}{\pi}\right)\left(1-\frac{x}{2\pi}\right)\left(1+\frac{x}{2\pi}\right)\dots$$  simply because they have the same roots, which is really not a strong enough condition. How do you really show that the equality holds?  He then notices that if you use the above equality, and consider it against the Taylor expansion for $\frac{\sin(x)}{x}$, then you can equate the coefficients of the two infinite expansions at each order, and the result of the Basel problem follows. But how do you know that if you have two different expansions for a function, then their coefficients at each order must be equal?  I would really appreciate if someone could show me how to make these two intuitive, yet informal, steps rigorous. .NET String.Format() to add commas in thousands place for a number I want to add a comma in the thousands place for a number.     String.Format()? I'm testing an application which opens its own ports (acts as a server for these ports, hence listens at that ports) and where the same application connects to ports bound by other applications (acts as client for these ports).  I would like to get an overview as to which ports the application creates and to which applications and ports it connects to.  How can I do this? Should 'using' directives be inside or outside the namespace? I have been running  over some C# code, and it keeps reporting that my using directives should be inside the namespace.  Is there a technical reason for putting the using directives inside instead of outside the namespace? What should we do with old, very popular closed questions? Motivated by the deletion of     On one hand, I disagree with these closures, because:  These questions were (and still are) very popular They have some good information in them (or at least the first one does) and it feels like bad sportsmanship to remove good information from the internet, particularly when it was contributed by your fellow users  Number 2 in particular bothers me. A lot. On the other hand, I do agree that:  The community of 10k users should be able to decide which closed questions they wish to delete on their own without me intervening These questions should definitely remain closed, because they either have an absurd # of answers, or are duplicates (though some duplicates ). Which means they are eligible for deletion … forever. These questions wouldn't survive more than 10 minutes if asked today on Stack Overflow, so in some ways they are artifacts from the past, like dinosaurs in an era of mammals.  There is some related discussion in:   While I normally favor code solutions here, I am not sure I like the idea that once a question gets 400 upvotes it should become extremely difficult to delete. It feels like mob rule. Official policy on the blog: Hint:  $a^2 -ab +b^2 = (a+b)^2 -3ab.$  I know we can say that there exists an $x,y$ such that $ax + by = 1$.  So in this case, $(a+b)x + ((a+b)^2 -3ab)y =1.$  I thought setting $x = (a+b)$ and $y = -1$ would help but that gives me $3ab =1.$  Any suggestions? Google Maps Location History is showing an incorrect location I have a major problem that I hope someone can help with. On my Google Maps feature under my Location History it shows a location that I was never at at any point, but when my wife happened to see that location she doesn't believe me that the GPS could be wrong and pinpoint that location if I was never there.  I was first wondering myself how could that could be possible if I was never there or my phone was never at that location that was 35 miles away from me and second is there any way I could prove the GPS being wrong? Can I contact Google Maps and can they give an official printout of that certain day and every location I was? I really need to prove my honesty to her and hope there is a way. How can I take a picture with my webcam in Windows 7? I know it existed as sort of a folder in Windows Explorer in at least Windows XP, but I just can't seem to find it in Windows 7...  How can I take a picture with my webcam in Windows 7 without using any 3rd party tools? How can I make environment variables "exported" in a shell script stick around? I have multiple Amazon EC2 accounts and want to quickly be able to switch variables, such as $EC2_HOME, using a script.  I have have a shell script set up like this:  #!/bin/sh export EC2_HOME=/home/me/.ec2 echo $EC2_HOME   When I run the script I know that EC2_HOME is set, but I thought that using export would make the variable stick around after the script completed. It does not, as running echo $EC_HOME does not show anything.  I know this must be very rudimentary Linux scripting knowledge, but I don't know it. I tried looking for related questions without luck - so my apologies if this is a duplicate. Difference between if () { } and if () : endif; Are there any differences between...  if ($value) {  }   ...and...  if ($value):  endif;   ? TP-LINK TL-WN823N Unable to connect to network I have purchased a TP-LINK TL-WN823N (EU) V2.0 device, which is a USB device that should work as a Network Interface Card, allowing me to connect my computer to wireless networks. Unfortunately, I am unable to find any wireless networks using this device using either wicd or network-manager (no networks appear in the list of networks supplied by either application).  A CD came with the device claiming "Linux support". The CD contained a URL to a corrupted archive file for downloading installation resources. I try to mask my immense frustration.  Here is the additional dmesg output I receive when I connect the device to my computer (similar content is present when I boot the computer with the device connected):  [17096.009912] usb 2-1.2: new high-speed USB device number 4 using ehci-pci [17096.103501] usb 2-1.2: New USB device found, idVendor=2357, idProduct=0109 [17096.103513] usb 2-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [17096.103527] usb 2-1.2: Product: 802.11n NIC [17096.103529] usb 2-1.2: Manufacturer: Realtek [17096.103530] usb 2-1.2: SerialNumber: 00e04c000001   This is my lsusb, where the offending device corresponds to Bus 002 Device 004:  Bus 002 Device 003: ID 0a5c:5800 Broadcom Corp. BCM5880 Secure Applications Processor Bus 002 Device 004: ID 2357:0109   Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 0c45:6433 Microdia  Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub   As lsusb -v:   It seems the device is working to me, but no new interface is found in 'ifconfig':  docker0   Link encap:Ethernet  HWaddr 02:42:6e:bf:92:16             inet addr:172.17.0.1  Bcast:0.0.0.0  Mask:255.255.0.0           UP BROADCAST MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)  enp0s31f6 Link encap:Ethernet  HWaddr 30:5a:3a:e1:96:b1             UP BROADCAST MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)           Interrupt:16 Memory:df200000-df220000   lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:65536  Metric:1           RX packets:412 errors:0 dropped:0 overruns:0 frame:0           TX packets:412 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1           RX bytes:31876 (31.8 KB)  TX bytes:31876 (31.8 KB)   Running 'lshw -class network' as root contains only information about the 'enp0s31f6' interface.  Additionally for sanity, my 'uname -a':  Linux home-z170a-ubuntu 4.4.0-22-generic #39=Ubuntu SMP Thu May 5 16:53:32 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux   I am using Ubuntu 16.04.  My questions are:   Why are no networks present in the list for wicd or network-manager? Why is there no additional network interface created when I plug in the USB device? Is it possible to create this network interface?   Thanks for reading. Limit $c^n n!/n^n$ as $n$ goes to infinity Let $c&gt;0$ be a real number. I would like to study the convergence of $a_n := c^n n!/n^n$, when $n \to \infty$, in function of $c$.   I know (from  question) that $n!&gt;(n/e)^n$, so that $c^n n!/n^n&gt;1$ for $c ≥e$. But this doesn't imply that the sequence goes to infinity. And I'm not sure what to do for $c&lt;e$. I tried usual tests (D'Alembert...), without any success. I would like to avoid using Stirling approximation.  Thank you for your help! Number of combinations of dice having different number of faces that add to $10$ A function $\textbf{face}_{\mathrm{sum}}$ that takes a vector  $f$ that represents the number of faces of each die, and a positive integer  $s$ , and returns the probability that the sum of the top faces observed is  $s$ .  For example, if $f=[3,4,5]$  and  $s≤2$  or $s≥13$ , $\textbf{face}_{\mathrm{sum}}$ returns $0$, and if  $s=3$  or  $s=12$ , it returns  $\frac13*\frac14*\frac15=\frac1{60}$  $\textbf{face}_{\mathrm{sum}}([2,4,4,6], 10)$  I tried to solve this but I can't find the formula to calculate the number of combination of die faces that add to $10$, as the number of faces are different for each die.  Since max no of possible combination is $6*4*4*2=192$, all I need to find is the number of combination of die faces that add to $10$.  Thanks in advance. If $a$ and $b$ are consecutive integers, prove that $a^2 + b^2 + a^2b^2$ is a perfect square. Problem is as stated in the title. Source is Larson's 'Problem Solving through Problems'. I've tried all kinds of factorizations with this trying to get it to the form $$k^2l^2$$ but nothing's clicking. I tried Bézout but the same expression can be written as $$a^2 + (a^2 + 1)(a+1)^2$$ which would imply that there is no real root.  Would really appreciate some help, thanks. What should main() return in C and C++? Windows page file on multiple hard drives I cant find any documentation or articles online online for this...  how does Windows handle page files on multiple hard drives?  Does windows treat them as a concatenation, writing to one till its full then moving to the next?  Or does it treat them like a stripe, writing to each one incrementally?  Does it write to the first one free?  Or perhaps some other method? Reputation and inbox notification shows up again after refresh Mathematics for Quantum Mechanics What math should I study if I want to get a basic understanding of quantum mechanics and especially to be able to use the Schrodinger's equation. How to read from two input files using while loop I wanted to know if there is any way of reading from two input files in a nested while loop one line at a time. For example, lets say I have two files FileA and FileB.   FileA:  [jaypal:~/Temp] cat filea this is File A line1 this is File A line2 this is File A line3   FileB:  [jaypal:~/Temp] cat fileb this is File B line1 this is File B line2 this is File B line3   Current Sample Script:  [jaypal:~/Temp] cat read.sh  #!/bin/bash while read lineA     do echo $lineA      while read lineB         do echo $lineB          done &lt; fileb done &lt; filea   Execution:  [jaypal:~/Temp] ./read.sh  this is File A line1 this is File B line1 this is File B line2 this is File B line3 this is File A line2 this is File B line1 this is File B line2 this is File B line3 this is File A line3 this is File B line1 this is File B line2 this is File B line3   Problem and desired output:  This loops over FileB completely for each line in FileA. I tried using continue, break, exit but none of them are meant for achieving the output I am looking for. I would like the script to read just one line from File A and then one line from FileB and exit the loop and continue with second line of File A and second line of File B. Something similar to the following script -  [jaypal:~/Temp] cat read1.sh  #!/bin/bash count=1 while read lineA     do echo $lineA          lineB=`sed -n "$count"p fileb`         echo $lineB         count=`expr $count + 1` done &lt; filea  [jaypal:~/Temp] ./read1.sh  this is File A line1 this is File B line1 this is File A line2 this is File B line2 this is File A line3 this is File B line3   Is this possible to achieve with while loop?