How to align container to body center?
How to horizontally center an element
Can command substitution be nested in variable substitution? "In back of'' vs. "back of" vs. the spatial sense of "behind" in AmE How to iterate through array combinations with constant sum efficiently? I always thought of current as the time derivative of charge, $\frac{dq}{dt}$. However, I found out recently that it is the ampere that is the base unit and not the coulomb. Why is this? It seems to me that charge can exist without current, but current cannot exist without charge. So the logical choice for a base unit would be the coulomb. Right? I am very confused about the probability formula $E[\min(X,k)]=\int_0^kxf(x)dx+k(1-F(k))$ I understand the proof of this first formula.  I am confused about where he got the first E[min(X, k)] formula. It seems to have just come out of nowhere. And also, can someone explain why the two formulas are correct please? All my properties are zero, and my array is zero, even though I have populated them with numbers and objects Is there a way so that I make make it when I left click/right click with a certain item it applies an effect? I know that you can apply attributes to wearing armor and things but I want it so when you use the item it applies an effect on your player.  For example, let's say I want something so that when I right click with a certain item (let's say an iron ingot that was given to me) I'll then have a jump boost for 10 seconds. So kinda like a potion in a way.  Is this possible with command blocks/commands/any mods? Is it possible that galaxies' redshift is caused by something else than the expansion of space? I was thinking that maybe photons loss energy naturally when they travel great distances.  Or maybe the mass of all matter is increasing over time and therefore photons emitted in the past are necessarily less energetic.  Or is the expansion of space backed up by so much other evidences that trying to find another explanation is completely foolish? How to play DVDs in Ubuntu 16.04? My question might appear the same as the question , but actually I did read all the answers and none of them helped me with the details I need.  I am new to cryptography and my problem is with two time pad attacks on OTP. The problem I had in my course was that I have 10 ciphertexts encrypted with the same key $K$. I am then given another ciphertext that I should decrypt.  I know that XOR-ing two ciphers gives me the XOR of their original messages.  My question is what is the correct thing to do after that?  I tried to take 3 ciphertexts $C_1, C_2$ and $C_3$.  Then get $S_1 = C_1 \oplus C_2  \oplus $' ', also get $S_2 = C_1 \oplus C_3 \oplus$ ' '.  After that I compared all corresponding characters in $S_1$ and $S_2$,  and if $S_1[i] = S_2[i]$ then I calculate $S_1[i] \oplus C_2[i]$ to get $K[i]$.  I tried this on paper before coding and it worked, but I might be missing something.  Is this the right approach? Why does it work? Roman numerals become “too wide” in table of contents What is there to do after beating the Elite Four/Champion (Post-Game)? I've defeated the Elite Four and the Champion. The credits rolled and I've been teleported to my home in Vaniville Town. What is there to do now? Any specific events/features that are unlocked now?  I already know of and caught Mewtwo and Zyrgarde. "Open in Terminal" in Ubuntu 18.04 This option seems to have gone away after upgrading from Ubuntu 16.04. I tried installing nautilus-open-terminal but it is unable to locate the package for 18.04. Also trying to install nautilus-actions gives:  Package nautilus-actions is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source     How to fix this? include svg images with the svg package Shell Type:  &gt;echo $SHELL /bin/ksh   Cronjob :   15 * * * * /bin/ksh /wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh &gt; /wls_domains/resMGT/logs/bea/data/script.log  The script is as below:  ##log files and lookup file "wlr3queue.txt" are in the same path of the script ##/wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh  Script :  #!/bin/ksh  dt=`date +%Y-%m-%d` xy=`date|awk '{print $4}'|awk -F":" '{print $1}'` yz=`expr $xy - 1` if [ $yz -le 9 ] then yz=0$yz fi  if [ $xy -gt 0 ] then  for i in `cat wlr3queue.txt` do  sum=0  count=`gzgrep -i "$dt" admin_resMGT_access.log* | grep "$yz:[0-5][0-9]" | grep "$i" | wc -l`  if [ $count -gt 0 ] then name=`echo $i | cut -d'/' -f3`  gzgrep -i "$dt" admin_resMGT_access.log* | grep "$yz:[0-5][0-9]" | grep "$i" | awk '{print $8}' &gt; consumed_time.txt  for j in `cat consumed_time.txt` do j_ms=`echo "$j * 1000" | bc` echo $j_ms &gt;&gt; consumed_ms_time.txt done  for k in `cat consumed_ms_time.txt` do sum=`echo "$sum + $k" | bc` done  avg=`echo "scale=2; ($sum/$count) "| bc`  min=`cat consumed_ms_time.txt | sort -n | head -1`  max=`cat consumed_ms_time.txt | sort -n | tail -1`  else  avg=0  min=0  max=0  fi ( echo $yz","$count","$avg","$min","$max )&gt;&gt;/wls_domains/resMGT/logs/bea/data/$name$dt.csv   rm -f consumed_ms_time.txt  done  else  echo "script won't execute at this hour" &gt; temp.txt  fi   I have executed the following commands and the script ran successfully.  ./wlr3queuetransaction.sh sh -x wlr3queuetransaction.sh /bin/ksh /wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh  /bin/ksh/ wlr3queuetransaction.sh.   How to debug? What to do? Radio antenna producing waves in the visible spectrum If a radio could produce waves in the visible light spectrum, what would the result be?  This is a thought experiment that I've pondered for a few years now.  I realize there are a few/many real-world constraints, but if we lifted these constraints for the sake of thought, what could we expect?  Personally, I don't see why we wouldn't observe visible light emitting from the antenna, disregarding any light from Blackbody Radiation. I'm working with some code that widely uses the idiom of returning a pointer to a static local variable.  eg:  char* const GetString() {   static char sTest[5];   strcpy(sTest, "Test");   return sTest; }   Am I right in thinking that this is safe?  PS, I know that this would be a better way of doing the same thing:  char* const GetString() {   return "Test"; }   Edit: Apologies, the function signature should of course be:  const char* GetString(); Recent feature changes to Stack Exchange This is an unofficial list/changelog of new features and various changes to Stack Overflow and the Stack Exchange network.  It is maintained by the community, while a Stack Exchange employee changes the accepted answer to ensure that the latest changes remain on top (given default user settings).  To see the list in reverse chronological order (latest entry on top), .  For those adding new features here: please post only feature changes that affect the whole network and have some global impact. i.e. bug fixes don't belong here, nor do mobile app updates. Intuition behind logistic regression Recently I began studying machine learning, however I failed to grasp the intuition behind .   The following are the facts about logistic regression that I understand.   As the basis for hypothesis we use . I do understand why it's a correct choice, however why it's the only choice I don't understand. Hypothesis represents the probability that the appropriate output is $1$, therefore the domain of our function should be $[0,1]$, this is the only property of sigmoid function I found useful and appropriate here, however many functions satisfy this property. In addition, sigmoid function has a derivative in this form $f(x)(1-f(x))$, but I don't see the utility of this special form in logistic regression.   Question: what so special about sigmoid function, and why we cannot use any other function with domain $[0,1]$? The cost function consists of two parameters ${\rm Cost}(h_{\theta}(x),y)=-\log(h_{\theta}(x))$ if $y=1, {\rm Cost}(h_{\theta}(x),y)=-\log(1-h_{\theta}(x))$ if $y=0$. In the same was as above, I do understand why it's correct, however why is it the only form? For example, why couldn't $|h_{\theta(x)}-y|$ be a good choice for the cost function?  Question: what is so special about the above form of cost function; why cannot we use another form?   I would appreciate if you could share your understanding of logistic regression. Merge two unadjacent partitions I have three partitions on my drive, arranged something like the following:   ___________ | 1 |  2 | 3| -------------   I wish to merge partitions 1 and 3.  Is there a way to do this, or do I have to manually "slide" partition 2 over to partition 3, and then merge the newly open space where partition 2 used to be?  Note: I do not have the space to copy partition 2 to partition 3 (2 is 200GB and 3 is 65GB).