If I run:  sudo apt-get dist-upgrade   It upgrades all the packages on my system, including LibreOffice, Chrome & Firefox, which for me is undesirable.  How can I tell Ubuntu to only install system patches, whilst allowing me to manually upgrade my applications?  I am using Ubuntu 14.04 x64

Because of  I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package.   How can this be achieved?


If I'm on , and I open the achievements dialog in the top bar (*I know there's a given name for this, but I don't recall it), the badge icon used will be from the sprite image of the current site. e.g., if on Programmers SE, you get the badge icon from  for a badge earned on Stack Overflow, which uses . Another example is the , which also uses significantly different icons for badges.  Perhaps each site's badge icons could be in a common file, such as the ? You would not need to include icons for all sites, since most use the common bronze, silver, and gold circles found in the .

It's so cool that the notification reminds you of the colour of badge you've earned. But I am a little puzzled by the symbols:      Is it feasible to use the symbol from the earned site? At the moment it uses the symbol from the site I happen to be on (as you can see by looking to the left of the dropdown in each case.)


My mother is going on a flight with United Airlines. I'm sort of nervous for her because she hasn't really been on a airplane since she gained much weight. She's pushing 400 pounds, even if it doesn't seem that, (her body seems smaller then her actually weight). I don't want her go to the airport and be humiliated over the fact of some random employee making her buy an extra seat, or anything.  What's the cut off for being to big?  Do you think she will fit or should I buy her an extra seat in advance?

As I said in another question, I'm bringing my parents to visit me here in Sweden next year.  My mother is around 280-300 pounds and 5'6" (130-135kg, 1.67m). I am concerned that she might be asked at the airport to buy a second seat. If it's likely I would rather just buy the second seat in advance, because I don't want her to be embarassed/humiliated by some random employee. As well, I won't be there, they will be travelling alone and aren't used to dealing with airports and they won't know what their rights are.  In terms of how it will affect other passengers, it's not important, she will get a window seat and my dad will sit in the middle seat, so I don't see it affecting anybody.   She insists it's fine, "the last time I flew I fit easily!" but that was 20 years ago when she was half the size.   They will be flying BA or SAS, definitely not Ryanair.  So - where is the cutoff? Is a 300 pound 5'6" woman going to be too big to fit in a single airline seat? Or am I worrying about nothing?


When flagging a question on mobile view, the pop-up becomes unusable. After choosing the first option and the content changes you can't see the rest of the options or submit.   Happens when there are no answers/few comments and the answer textarea is visible. The pop-up is forced behind the textarea.

The "Your Answer" textbox seems to be eating the flagging dialog as shown in Figure A.


Bash scripts start with the following line  #!/bin/bash # Rest of script below ...   In bash the # character is the start of a comment, but #!/bin/bash is definitely not a comment, therefore  that interprets that statement.  So what exactly is that first line? Is it a specific language, or a special one-off case in the Linux kernel? Are there other commands or statements in this "language" that can be used when scripting?

This may be a silly question, but I ask it still. If I have declared a shebang  #!/bin/bash    in the beginning of my_shell_script.sh, so do I always have to invoke this script using bash  [my@comp]$bash my_shell_script.sh   or can I use e.g.  [my@comp]$sh my_shell_script.sh   and my script determines the running shell using the shebang? Is it the same happening with ksh shell? I'm using AIX.


When i created a cube that surrounds the whole scene it looked pretty however it decreased my sun lamp's emission effect on my bushes and doing so it decreased glossy level of my plants which its not a thing im comfortable with i tried to increase my sun's emission level but didnt do it

I have to have a spot lamp strength VERY VERY high to have these light rays come through 300000.0 and look good.  Sounds crazy doesn't it.  Maybe it doesn't matter but it doesn't feel right.  Will I start to have problems if add other elements?   Lamp Size: .2 Lamp Strength: 300000.0 World Volume: Volume Scatter World Volume Density: .05  World Volume: Homogeneous: True Render Sampling Settings Clamp Indirect: 3.0  Rendering No Caustics: True


Now I find that wc -c could show the size of file, then how to select them and list them? It should be a single pipeline of commands.

I have a linux server, which currently has below space usage:  /dev/sda3              20G   15G  4.2G  78% / /dev/sda6              68G   42G   23G  65% /u01 /dev/sda2              30G  7.4G   21G  27% /opt /dev/sda1              99M   19M   76M  20% /boot tmpfs                  48G  8.2G   39G  18% /dev/shm   As you can see. / is at 78%. I want to check, which files or folders are consuming space.  I tried this:  find . -type d -size +100M   Which shows result like this:  ./u01/app/june01.dbf ./u01/app/temp01.dbf ./u01/app/smprd501.dbf ./home/abhishek/centos.iso ./home/abhishek/filegroup128.jar   Now this is my issue. I only want the name of those files located in folders that are consuming space at / and not at /u01 or /home. Since / is base of everything, it is showing me every file of my server.  Is is possible to get big files that is contributing to 78% of / ?


The mass of nucleons is bigger than the sum of the masses of its constituent quarks. I understand that it's because you have to take into account the binding energy of these quarks.   What I don't understand is this: In a nuclear physics course I was tought that the mass of the nucleai is less than the sum of the masses of its constituent nucleons because the binding energy between them is negative in order to make it stable.   So, if the binding energy of nucleons is negative because its suppose to be an atractive force that keeps nucleons stable, why does the binding energy of quarks add to the mass of nucleons instead of reducing it if it's also an atractive force keeping quarks stable?  I understand that in the quark regime we have to deal with quantum chromodynamics and the concept of force and energy are not that simple but I was expecting the binding energy of any atractive interaction to be negative anyway...

We know that the sum of the masses of the quarks in a proton is approximately $9.4^{+1.9}_{-1.3}~\text{MeV}/c^2$, whereas the mass of a proton is $\approx931~\text{MeV}/c^2$. This extra mass is attributed to the kinetic energy of the confined quarks and the confining field of the strong force. Now, when we talk about energetically favourably bound systems, they have a total mass-energy less than the sum of the mass-energies of the constituent entities. How does a proton, a bound system of quarks with its mass-energy so much more than its constituent entities, remain stable? The strong force and other energetic interactions supposedly contribute this mass-energy by the mass-energy equivalence principle, but how exactly does this occur?


I have gedit-plugins installed for gedit on my previously broken system. On the new system, I want to restore gedit from my backed up home directory.  I will like to know! Where does gedit store it's configurations including plugins list, preferences etc.  Thanks for helping out.

I am a bit confused as to where I should put externally downloaded plugins. I have tried putting them in:   /usr/share/gedit/plugins ~/. Local/gedit/plugins ~/. Gnome2/gedit/plugins /usr/lib/gedit/plugins   The way I have checked whether the plugins show up or not is going to Edit -> Preferences -> Plugins and looking for the ones I have downloaded (clickconfig, gedit-developer-plugins-...). Since I do not see any new plugins appearing, I have to assume that I am doing something wrong.  None of these have worked. I am a bit tired of polluting my system. It's probably my own fault as it's written somewhere I have not thought to look. Please let me know how to add external plugins to Gedit properly. I am running Ubuntu 11.10. My Gedit version is 3.2.3    EDIT:   I am still not able to solve this problem. I have tried the following folder now as well, and it hasn't worked:  ~/. Config/gedit/plugins  EDIT 2:   I am trying to install the plugins in "gedit-developer-plugins" as well as the "clickconfig" plugin.


Hey I'm a noob to physics however after reading about black holes and Hawking radiation.  If a black hole made entirely out of negatively charged particles (say this black hole is made entirely of electrons) Then when it evaporates equal parts positive and negative particles (positrons and electrons for this example) are created. Doesn't this violate the law of conservation of charge?

Black holes evaporate (Hawking Radiation) acting as black bodies with the temperature inversely proportional to the mass.  No physical process, be it evaporation or any other "trick", can make a black hole "super-extremal", namely it can't make the square of the angular momentum or the charge too large compared to the mass. As the mass drops due to evaporation the charge and angular momentum must also drop.  Angular momentum can be shed with photons, because photons have spin and can be emitted in a non-radial direction.  Charge is trickier. There are three methods to shed charge:   Accrete oppositely charged particles. This can be stopped, hypothetically at least, by isolating the hole. Emit charged particles. There are no massless charged particles, so a temperature << 511keV strongly suppresses this positron and electron generation, so making the hole large enough should stop this. Break down the vacuum with the electric field (requires ~10^18 V/m). Again, making the hole large enough should suppress this because the electric field in the vicinity of a near-extremal charged hole scales as 1/M.   If all three of these are suppressed, we have a new candidate for the longest lived objects possible! So will a large enough black hole evaporate itself toward extremity after which there will be essentially zero Hawking radiation?


I've seen anonymous functions like:  @(eta) 30*eta^2;   but they mostly are one liners. Is it possible to have them have more than one line like:  @(eta) (x =eta^2; y=eta^3; return x+y; )   where one has more lines and variables defined in the anonymous function but let it remain as an anonymous function?

I'd like to do something like this:  >> foo = @() functionCall1() functionCall2()   So that when I said:  >> foo()   It would execute functionCall1() and then execute functionCall2().  (I feel that I need something like the )  EDIT:  functionCall1 and functionCall2 are not necessarily functions that return values.


I am trying to create a regex expression I can extract a name between a specific constant word and a period.   Test sentence:  Welcome Back Kumar. Your last login was April 10 2017.  Result: I want to extract the "Kumar" from the sentence.  I did create the following regex expression:  Back\s*(\w+)[^.]  And the result is as follow: "Back Kumar"  I can't find way to remove the "Back" word and the period at the end.

I want to match a portion of a string using a  and then access that parenthesized substring:  var myString = "something format_abc"; // I want "abc"  var arr = /(?:^|\s)format_(.*?)(?:\s|$)/.exec(myString);  console.log(arr);     // Prints: [" format_abc", "abc"] .. so far so good. console.log(arr[1]);  // Prints: undefined  (???) console.log(arr[0]);  // Prints: format_undefined (!!!)   What am I doing wrong?    I've discovered that there was nothing wrong with the regular expression code above: the actual string which I was testing against was this:  "date format_%A"   Reporting that "%A" is undefined seems a very strange behaviour, but it is not directly related to this question, so I've opened a new one, .    The issue was that console.log takes its parameters like a printf statement, and since the string I was logging ("%A") had a special value, it was trying to find the value of the next parameter.


Somewhere I read that the  pulsar can not differentiate between competing theories assuming different speeds of gravity. Is it mathematically true in general, that the orbital decay of two orbiting bodies cannot possibly favor certain speeds of gravity over others? If so, why is it the case? Any references would be much appreciated! Edit: I found  where I read it:  The speed of gravitational radiation ($C_{gw}$) depends upon the specific model of Gravitation that you use.  There are quite a few competing models (all consistent with all experiments to date[~1992]) including of course Einstein's but also Brans-Dicke and several families of others.  All metric models can support gravitational waves.  But not all predict radiation travelling at $C_{gw} = C_{em}$.  ($C_{em}$ is the speed of electromagnetic waves.)  So, is it possible to construct a metric theory of gravitation with arbitrarily chosen $C_{gw}$, so that it will be consistent with orbital decay experiments to date? If not, what is the possible range. I believe it must have been discussed in scientific literature, but I can't find anything. I know that it can be a very hard question to answer with mathematic rigor, but a non-technical overview should be sufficient.

In replying to a  I stated:     Gravitational waves have not been yet experimentally observed so as to have their velocity measured.   Which after the fact prompted me to try and verify it. I found a "speed of gravity" claimed measurement, which has been in a controversial discussion. In the last paragraph of  I found:     In September 2002, Sergei Kopeikin and Edward Fomalont announced that they had made an indirect measurement of the speed of gravity, using their data from VLBI measurement of the retarded position of Jupiter on its orbit during Jupiter's transit across the line-of-sight of the bright radio source quasar QSO J0842+1835. Kopeikin and Fomalont concluded that the speed of gravity is between 0.8 and 1.2 times the speed of light, which would be fully consistent with the theoretical prediction of general relativity that the speed of gravity is exactly the same as the speed of light.[18]   There has been criticism, described in the paragraph.   Has this matter been resolved ? is the measurement valid?  The speed of gravity has also been  calculated from observations of the orbital decay rate of binary pulsars and found to be consistent to the speed of light within 1% ( same link).  This is the speed that gravitational fields transfer information, and though the number itself depends on the theoretical framework solving for the system parameters it is true that just the existence  of gravitational damping in the binary system would imply that the speed cannot be infinite.  Along these lines I was wondering whether studying the second star in a binary system where the first has gone nova would not give a cleaner and model independent measurement of the speed of transfer of information gravitationally. In this day and age where everything is digital one should be able to have data on this from now on.     (Feb 11,2016) announced the observation of gravitational waves , at the same time  consistent with the speed of light being c, and thus measuring it. See the  for a summary.


Does time really exist? or is it a human invention and convention? What is the truth? are there time particles? please remember, I'm looking for constructive answers, not condescending and void ones.

It seems to me that there is no such thing as time. There  is only movement in the universe and we compare our own movement to a different object to have a sense of time. It can be a clock or a atomic vibration.  Does this view of time work within the current framework of phsics?  Do physicists have an explanation/proof about time's existence?


How do I get the 3d manipulator widget to appear on a selected object in Blender 2.8. When I select any object in the scene the widget does not appear with it. Is there a menu item that makes it appear?

I would like the local coordinate system of an object to be drawn on the object, just like with empties. Is there a way to enable this?


Suppose the a system has a Hamiltonian $H = H(q,p)$, and suppose $H$ does not depend explicitly on time. If $H\neq E$ the total energy of the system, does this necessarily say that $E$ is not conserved? Why?

I'm looking for an example of a Hamiltonian $H$, where $H\neq T+V$, but the total energy in the system, $E=T+V$, is still conserved.   While I'm at it, I might as well add that I'd be most interested in an example from a classical field theory. Furthermore, I am looking for a nontrivial example, e.g. where $H$ doesn't just differ from $E$ by some gradient function that integrates to 0 in the action.   In particular, I am trying to get a better understanding of the physical implications of $H$ being conserved when nontrivial variables are used, i.e. physically, what does $H$ this correspond to. Conversely, can one have a system where $E = H$ in one frame, and is conserved, while in another frame $E'\neq H'$, and $H'$ is conserved while $E'$ is not?


In my case, it seems as if LD_LIBRARY_PATH is set to the empty string. But all standard system tools still work fine, so I guess the dynamic linker checks for that case and uses some default for LD_LIBRARY_PATH in that case.  What is that default value? I guess it at least includes /usr/lib but what else? Is there any good systematic way in figuring out the standard locations where the dynamic linker would search?  This question is slightly different from what paths the dynamic linker will search in. Having a default value means, that it will use the value of LD_LIBRARY_PATH if given, or if not given, it will use the default value - which means, it will not use the default value if LD_LIBRARY_PATH is provided.

I understand how to define include shared objects at linking/compile time. However, I still wonder how do executables look for the shared object (*.so libraries) at execution time.  For instance, my app a.out calls functions defined in the lib.so library. After compiling, I move lib.so to a new directory in my $HOME.  How can I tell a.out to go look for it there?


The Narrator on my computer (Windows 7 version) turned on somehow and won't turn off. I have already been to the Ease of Accessibility section and unticked all the options that tell it to use the Narrator, and I have tried the Windows + Enter shortcuct . . . nothing works.

I hate narrator. I realize it can be helpful for people that can't see well but I don't have that problem. I keep accidentally pressing whatever keys open it (I still haven't found out what it is) and losing focus on whatever program I had open. Is it possible to remove narrator from my computer forever?


After deleting something on my Samsung n150 netbook, I am now trying to reboot. Grub rescue cannot go over the “normal mod not found” error.  Any suggestions?

error: file '/grub/i386-pc/normal.mod' not found. grub rescue>   What can I do? I just sit and stare at it.   I found my old netbook (Dell Inspiron 1010) which I have not used for about four years. I replaced Windows XP with Ubuntu 12.10. I used my bootable USB drive. I installed and rebooted. I got the message that normal.mod is not found.   What should I do? Type exit, reboot, or quit? Should I re-install?


I am attempting to run this find command to match files with a camelcased name, with the goal being to put a space between adjacent lower and upper case letters, but it's not matching anything:  find -E . -regex "([a-z])([A-Z])"   An example of a file I'm trying to match is  ./250 - ErosPhiliaAgape.mp3   I've tested this regex on this file  and it matches successfully.  What is it I'm doing wrong with my find command?

I wrote a regular expression which works well in a certain program (grep, sed, awk, perl, python, ruby, ksh, bash, zsh, find, emacs, vi, vim, gedit, …). But when I use it in a different program (or on a different unix variant), it stops matching. Why?


I am new to stack overflow and I would appreciate feedback. I am creating a template graph class and have split it into two files graph.h and graph.hpp, but everytime I compile I get this error:      In file included from graph.h:97:0,                      from main.cpp:2:     graph.hpp:4:26: error: expected unqualified-id before ‘)’ token      typename graph<T>::graph(){                           ^ makefile:2: recipe for target 'executable.x' failed   Here is my graph.hpp file so far:  #include "graph.h"  //template <typename T> typename graph<T>::graph(){    numVertices = 0;    graphWeight = 0; }   And my graph.h file looks something like:  template <typename T> class graph{     public:       graph(); . . .    private:    };   Also, my main.cpp is just simply:  #include "graph.h"  int main(){    graph<int> g;  }   What could possibly be wrong? I know it's probably something simple that has to do with the template.  Thanks

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


Could you explain the magic behind (1+3)[a] indexing as in the following code? ()  #include <iostream>  int main(int argc, const char * argv[]) {     int a[] = {1, 2, 3, 4, 5, 6};     std::cout << (1 + 3)[a] - a[0] + (a + 1)[2]; }   Is this indexing some relic of C language? I thought indexing operator [] cannot take an array in it. Would the same work for e.g. std::vector?

As Joel points out in , in  (aka: K & R), there is mention of this property of arrays in C: a[5] == 5[a]  Joel says that it's because of pointer arithmetic but I still don't understand. Why does a[5] == 5[a]?


I need to change the caption Figure to Fig. for a journal. I am currently using:   \usepackage[font=small,labelsep=period]{caption} and  %Caption display style \captionsetup{figurename=Fig.,tablename=Table}   to rename the caption. The \autoref however, is still showing a Figure 1 instead of Fig. 1. Can someone tell me the alternative to the code \addto\extrasngerman{\renewcommand\figureautorefname{Abb.}} used in , applicable for Caption package.

in this example, how can I customize \autoref. ie instead of printing table 1, it puts Tab.1 same question with Figure = Fig. and equation = Eq.  \documentclass{article} \usepackage[T1]{fontenc} %\usepackage[francais]{babel}  \usepackage{graphicx} \usepackage[font=footnotesize,labelfont={bf,sc,small},figurename=Fig.,tablename=Tab.]{caption} \usepackage[colorlinks=true,linkcolor=blue]{hyperref}   \begin{document}  change the writing of \autoref{tab} to Tab.1  \begin{table}[htbp] \begin{center} \begin{tabular}{|l|l|} \hline table & Tab. \\ \hline figure & Fig. \\ \hline equation & Eq. \\ \hline \end{tabular} \end{center} \caption{Exemple d'environnement table} \label{tab} \end{table}  \end{document}


Running Arch Linux Arm on my Beagleboad xM I'm trying to set up a web server to listen for commands, however whenever I try to compile a program that requires "netinet/in.h" it outputs the following errors:  netTest.cpp:(.text+0x14c): undefined reference to `__cxa_end_cleanup' /tmp/ccaJk7mW.o:(.ARM.extab+0x0): undefined reference to `__gxx_personality_v0'   Am I missing something? Can you compile on ARM? Any help is greatly appreciated, thanks!

I've been getting this undefined symbol building with this command line:  $ gcc test.cpp Undefined symbols:   "___gxx_personality_v0", referenced from:   etc...   test.cpp is simple and should build fine.  What is the deal?


Many game allows the player to save progress at any time and load the save back at any time (like Minecraft and Doom 3).  I would like to implement it in Unity.  I think I will need to put the value of every variable in every script into a save file, but how? Or maybe not?

I am making a game using the Unity game engine. I want to save the player's progress including level, experience points, chosen character, etc. Presently I am using playerprefs but I want to know whether this will work for gamers who will run this game on their mobile devices (Android/iOS) as well as desktops (OSX/PCs)? If not, then how should I save this information? I want to auto-save player progress after clearing each stage.


Let $\phi:\mathbb{R} \rightarrow \mathbb{R}$ be a ring homomorphism onto. Prove or disprove: $\phi(r)=r$ for all $r\in \mathbb{R}.$   Attempt: I believe it is true! Since $\phi(1)=\phi(1\cdot 1)=\phi(1)^2$ we get  $\phi(1)=1$, since $\phi$ is onto. Then quite easily we get $\phi(m)=m$ for $m\in \mathbb{Z}$ and $\phi(q)=q$ for $q\in  \mathbb{Q}$. How do we go on from this point, to conclude for $\mathbb{R}$?

Is an automorphism of the field of real numbers $\mathbb{R}$ the identity map? If yes, how can we prove it?  Remark An automorphism of $\mathbb{R}$ may not be continuous.


all, I am new to blender, so sorry if my question seems dumb. I just animated a camera to follow a bezier path. Now, I need to keep animating the camera, but I would like to either free the camera from the path or to follow a different path. So, this is my question: is it possible to animate camera alternating among different bezier paths? Thank you!

I currently use a Track to Constraint to make the camera automatically point to an empty.   In an animation the camera is moved along a bezier curve (follow path).   How could I change the curve and track to constraint at a certain frame to focus on another aspects of the scene?


If a user asked a question and got an answer which was not helpful.  After sometime the answerer edits the answer with some good content. How the OP will get to know that?  Is it necessary to add comment check my edited answer?  We can say that the OP should refresh the page to find the helpful answer.  Consider if the OP finds the answer as helpful and accepted that. After sometime if the answerer/anyother user edit the answer to change the content which may not solve the issue.   How will it be notified to OP?  currently we are notifying the OP when there is any comment to the queation or any new answers or any comments with the name of OP with @ to any answer.  This will lead the future visitors to confuse and reduce the quality of post.  Can we have a notification to the original poster when the answer to any of his/her question got edited?

Seriously, I had not noticed e.g. Jeff's edit  had he not also retagged my question.


In bash, when you source a file with dot:  . /some/script   you can pass positional arguments to that script:  . /some/script hello world   and then access them in the script with $1, $2, ... etc as usual.  However, if they are omitted the script gets the positional arguments of the enclosing script, that is, if you have:  #!/bin/sh #--------------script1 . ./script3 hello world  #!/bin/sh #--------------script2 . ./script3   #--------------script3 echo $1 $2   and then do:  ./script1 ./script2 bonjour monde   Your results are:     hello world   bonjour monde   So, is there any way as the author of script3 to tell if your positional arguments were passed explicitly to you (as script1 does) or just got copied from the outer script (as in the script2 example)?  [EDIT] Per the suggestion in the comments, I added printing of the values in the BASH_ARGV array so script3 is now:  echo ===========script3====== echo dollar-number args: 0=$0, 1=$1, 2=$2 for i in ${!BASH_ARGV[@]} ; do         echo BASH_ARGV[$i]: ${BASH_ARGV[$i]} done echo ""   But the results are confusing:  ./script1   script1 calling script3 with args: hello world   ===========script3======   dollar-number args: 0=./script1, 1=hello, 2=world     ./script2   script2 calling script3 with no args:   ===========script3======   dollar-number args: 0=./script2, 1=, 2=   BASH_ARGV[0]: ./script3     ./script1 bonjour monde   script1 calling script3 with args: hello world   ===========script3======   dollar-number args: 0=./script1, 1=hello, 2=world   BASH_ARGV[0]: monde   BASH_ARGV[1]: bonjour     ./script2 bonjour monde   script2 calling script3 with no args:   ===========script3======   dollar-number args: 0=./script2, 1=bonjour, 2=monde   BASH_ARGV[0]: ./script3   BASH_ARGV[1]: monde   BASH_ARGV[2]: bonjour   Why is BASH_ARGV[0] sometimes the script name and sometimes missing and sometimes the last argument?  Also the arguments are in reverse order?  What a mess.

A script on AIX which checks the number of parameters passed and complains if they are not correct:-  if [ "$#" -ge 1 ]; then   ... else   echo 'Usage: myscript <a> [b] [c]' fi   The script sets some environment variables so it is sourced. By that I mean I type the following on my command line. There is no second script, I am not sourcing a script from within another script.  . ./myscript.sh   If I pass it no parameters, I expect it to print out the usage statement but instead it runs using the parameters passed to the previous command that was sourced (not necessarily even this script!).  To double check this I added this line at the beginning of my script to prove that this was the case.  echo $# $@   If I pass it no parameters, it prints out the number and the list of parameters from a previously sourced script.  How do I get it to say $# is zero when I pass it zero parameters and source it?  The smallest possible recreate is a script thus:-  myscript.sh  echo $# $@   and then run it thus:-  . ./myscript.sh a b c   which prints out  3 a b c   then run it again without any parameters thus:-  . ./myscript.sh   which prints out the same  3 a b c   when you would expect it to print out  0   If you don't source the script and just run it thus:-  ./myscript.sh   then it works as expected and prints out  0   I hope that clarifies the issue at hand.  Since I seem to be getting lots of answers to explain why the above doesn't work and no answers to tell me what I should do instead, I thought I would have one more attempt at trying to explain what I am trying to do.  Requirement  I need to write a script that expects at least one parameter and complains if it is not invoked with a said parameter (see the first block of code in my question above), and this script needs to set some environment variables. Because of this second requirement I have assumed that I need to source the script so that the environment variables are still set when the script completes. How can you write a script that can tell when it has not been passed parameters that is also able to set an environment variable?


I have a universal laptop adapter with listed voltage that i can set 12v/15v/16/18/19/20/24v.. i want to try it on my asus laptop with battery rating of +10.8v 4400mah, 27wh.. it's an li-ion battery. But i'm not sure if it's safe or not..  This is the universal adapter i have   Input: 110v-240v - 50/60hz 1.5A Max Output: 12/15/16/18/19V 4.5A Max 20/24V 4A Max

Possible Duplicate:        I have the opposite problem outlined in   My AC adapter (19 V, 3.95 A, 75 W, 3-pin) Part No. PA3468E-1AC3 for Toshiba Laptop L40 18Z is now useless. I am currently risking using an IBM Thinkpad adaptor (my old laptop) after checking the specification. The centre pin polarity is the same, I cannot currently find any references to Wattage output for the IBM adaptor - but the only difference I can find is in current and voltage.  The defunct Toshiba adapter is rated 19 V and 3.95 A. The IBM adapter is rated 16 V and 4.5 A.  I've used the IBM for several hours with no ill effect - risky I know! The lower voltage means that the battery isn't charging - but my concern is the higher current - 0.55 more.   Could this damage the sensitive internal electrics in the longer term - or is it unlikely to make a difference. If it works, which it does - could I confidently continue to use this until I've sourced a proper replacement?


Not a duplicate. This deals with sets that are elements of other sets. In other words, sets of sets. The other question deals with elements of sets and subsets of sets. The key difference in here is that the sets are the elements. Besides the other question only asks if $A \subset A$ which is trivial.   When it comes to sets of sets, $ \subset$ and $\in$ always confuse me in set theory. Could someone explain in detail with an example? I greatly appreciate it.  In other words, when do we say $\mathbb{A} \in \mathbb{B}$ and when do we say $\mathbb{A} \subset \mathbb{B}$ (besides the definition that every element in  $\mathbb{A}$ ought to be in  $\mathbb{B}$)  Thank you

This is a total noob question.  I am reading , and I'm having difficulty to understand something which seems to be trivial.  In the first chapter he writes:     If $x$ belongs to $A$ ($x$ is an element of $A$, $x$ is contained in $A$), we shall write      $x\in A$   I understand this.  Then, he write:     If $A$ and $B$ are sets and if every element of $A$ is an element of $B$, we say that $A$ is a subset of $B$, or $B$ includes $A$, and we write:      $A \subset B$   I understand this too.  Then he says:     The working of the definition implies that each set must be considered to be included in itself ($A \subset A$); this fact is described by saying that set inclusion is reflexive.   I understand this too.  But then:     Observe that belonging ($\in$) and inclusion ($\subset$) are conceptually very different things indeed. One important difference has already manifested itself above: inclusion is always reflexive, whereas it is not at all clear that belonging is ever reflexive. That is: $A \subset A$ is always true;  is $A\in A$ ever true? It is certainly not true of any reasonable set that anyone has ever seen.   And this is where I don't think I understand anything.  There is not more elaboration on this point in the text.  I tried to skip this but it seems it is quite fundamental for understanding what follows in the book.  Could someone explain what is meant here?


I've been reading threads here on how to format the string date probably, however it wont add the date. Instead it just adds 0000-00-00. How come it wont format the string date?  the $date variable could for instance be equal to 10/10/2014      $date = str_replace('.', '-', $undate);     $timestamp = strtotime($date);     $newdate = date("Y-m-d", $timestamp);     $wpdb->query("INSERT INTO " . $your_db_name . "         (date, time, hometeam, awayteam, score)          VALUES ($newdate, '$time', '$opp1', '$opp2', '$score')");

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I try to run tkz-fct in drive D with location  D:\latexrun but it can not work. Then I notice that package only run well in drive C as my Miktex location in C:\Program Files\MiKTeX 2.9 and in C:\Users\user\AppData\Roaming\MiKTeX .  In drive D the message show :  ! Undefined control sequence. l.10 \tkzSetUpColors ! Undefined control sequence. l.17 \tkzAxeY !  Undefined control sequence. l.19 \tkzDefPoint Undefined control sequence. \pgfutil@reserved@c ->\tkzActivOff ! File ended while scanning use of \pgfkeys@code.   This is sample I got from     which is run well in drive C but not in drive D.  \documentclass{scrartcl} \usepackage[utf8]{inputenc}   \usepackage[upright]{fourier} \usepackage[usenames,dvipsnames]{xcolor} \usepackage{fullpage,amsmath,tkz-fct} \definecolor{fondpaille}{cmyk}{0,0,0.1,0} \pagecolor{fondpaille} \color{Maroon} \tkzSetUpColors[background=fondpaille,text=Maroon] \thispagestyle{empty}  \begin{document}  \begin{tikzpicture}[scale=3] \tkzInit[xmax=3,ymax=2]; \tkzAxeX \tkzAxeY \tkzGrid(0,0)(3,2) \tkzFct[color  = red, domain = 1./3:3]{0.125*(3*\x-1)+0.375*(3*\x-1)/(\x*\x)} \tkzDefPointByFct[draw](2)  \tkzDefPointByFct[draw](3) \tkzDrawTangentLine[color = blue,line width = .8pt](1)  \tkzFct[color   = green, domain  =  1./3:3]{0.125*(3*x-1)} \tkzSetUpPoint[size=8,fill=orange]  \tkzDefPointByFct[draw](3)  \tkzDefPointByFct[draw](1/3)  \tkzDefPoint(1,1){f} \tkzDrawPoint(f) \tkzText[draw,fill = red!20,text=red!50!black](1,1.5)% {$f(x)=\dfrac{1}{8}(3x-1)+\dfrac{3}{8}\left(\dfrac{3x-1}{x^2}\right)$} \tkzText[draw,fill = green!20,text=green!50!black](2,0.4){$g(x) = \dfrac{3x-1}{8}$}     \end{tikzpicture} \end{document}   I have no problem calling gnuplot or another packages in drive D previously. I use Windows Vista Japanese Version SP2. Please help what should I do to make tkz-fct can run in another drive.

I'm new to LaTeX, investigating using it for some work projects.  I'm using MiKTeX on Windows.  My employer's locked-down network blocks the application's automatic installation function.  I can take my laptop home and successfully install from there, but if I need a package in the middle of the day I'm stuck.  I am able to access the CTAN website and download the package files (.dtx or .ins?), but I don't know what do do with them.  How can I do a manual package installation?


Exercise: Let $E$ be a finite extension field of $F$, and $D$ an integral domain such that $F \subset D \subset E$. Show that $D$ is a field.  Attempt: All of the field axioms for D are inherited by the inclusion relationship and ring axioms except for the existence of multiplicative inverse. $\alpha \in D \cap F \implies \alpha^{-1} \in F \implies \alpha^{-1} \in D$, so consider $\beta \in D \backslash F$.  Since $E/F$ is finite it's also algebraic, but then $F[\beta] = F(\beta)$ and so $\beta^{-1} \in F(\beta) \subset D$.  I'm not really sure this proof is correct, but in case it is there are two things that bug me:   If we just ask $D$ to be a ring then from $D \subset E$ follows $D$ is an integral domain. We only used the fact that $E/F$ is an algebraic extension in the proof.   Thanks for your help.

This is an exercise in some textbooks.     Let $E$ be an algebraic extension of $F$. Suppose $R$ is ring that contains $F$ and is contained in $E$. Prove that $R$ is a field.   The trouble is really with the inverse of $r$, where $r\in R$. How to prove that $r^{-1}\in R$, in apparent lack of a characterization of $R$.  It occurred to me to use the smallest field containing $R$ ($R$ is easily shown to be an integral domain), that's the field of quotients, and proving that it's $R$ itself, but I don't really know how to proceed.  A not-too-weak, not-too-strong hint will be much appreciated.   Beware $ $ Readers seeking only hints should  beware that there is now a complete answer.


Let $d\in\mathbb N$, $U\subseteq\mathbb R^d$ be open, $v\in C^1(U,\mathbb R^d)$ and $K\subseteq U$ be compact.  Can we show that $\left.f\right|_K$ is Lipschitz continuous?  Since $f$ is differentiable, there is a $(\delta_x)_{x\in U}\subseteq(0,\infty)$ with $$\left\|f(x)-f(y)\right\|\le\underbrace{\left(\left\|{\rm D}f(x)\right\|_{\mathfrak L(\mathbb R^d)}+1\right)}_{=:\:c_x}\left\|x-y\right\|\;\;\;\text{for all }y\in B_{\delta_x}(x)\tag1.$$ And since $K$ is compact, there are $k\in\mathbb N$, $x_1,\ldots,x_k\in K$ with $$K\subseteq\bigcup_{i=1}^kB_{\delta_{x_i}}(x_i)\tag2.$$ I would like to conclude from that, but I guess it will not work.

Let $f: \Omega \subseteq \mathbb{R}^N \to \mathbb{R}^M$ be $C^1$, and $K \subseteq \Omega$. Prove that $f \mid_K$ is Lipschitz.    Letting $x,y \in K$, I know that $f$ is loccaly Lipschitz, I thought about taking a finite subcover of $K$ by  the open cover of the balls which makes $f$ locally Lipschitz, and then take a sequence of $x_k, k=0,\dots, n$ in such that $x_0 =x$ and $x_n=y$, $x_k =y$ and $(x_i)$ are aligned, then try to use $|f(x)- f(y)| \le \sum_{i=1}^{n}|f(x_{i=1})- f(x_i)|$. But the very first problem is to take this sequence as $K$ is not necessary convex.  Again, if $K$ was convex I would make use of the Mean Value Innequality and that $K$ is compact to limit the value of $||Df_{p}||$, but as it is not the case I don't know how to procede.   So how can I avoid that? Does it hold for a general $K$ compact?  Finally, I am aware of this , but his question ,at the end, was only concearning the continuity, which I already know how do deal with there was no useful answer, nor comment for me, I apologise if I acted wrong by oppening a new one.


Using the allowframebreaksoption on a Beamer frame to split it up with the \framebreak command, the title gets an automatic counter.   This is a very handy feature, but I have a few concerns about the default appearance of the counter:   It gets typeset in roman numbers. With sans serif fonts usually used in presentations, this means the title on the first slide looks very odd. It gets appended to the title and typeset as part of the title, while it would often be more appropriate to typeset it as a subscript and/or aligned on right (if the title is aligned on the left) I'd prefer the number to appear only from the second frame Sometimes it is better to replace the counter with a simpler  "(continued)" mark or similar   Are there general options to control this behavior, or is it totally in the hand of how the theme typesets the frame title?  In particular, how can I switch to arabic numbers and make it a subscript? Avoiding the counter on the first slide would also be great.

I would like to change the numbering of allowframbreaks frame, for instance, from I II III to (1/3) (2/3) (3/3)， but fail to find out a command to get the total continuation count. Here is the MWE.  \documentclass[compress]{beamer} \usetheme{Warsaw}   %allowframebreaks numbering in the title \setbeamertemplate{frametitle continuation}{(\insertcontinuationcount/)} %\setbeamertemplate{frametitle continuation}{(\insertcontinuationcount/\inserttotalcontinuationcount)}  \title{title} \author{author}  %%%%% \begin{document}  \begin{frame}[allowframebreaks]{allowframebreaks title} frame 1 \framebreak  frame 2 \framebreak  frame 3 \framebreak \end{frame}  \end{document}


My son just received a "Disney Junior" DVD as a birthday present. It won't play in Ubuntu - in fact, Ubuntu only sees an empty disc! This is on 2 separate computers at home running Ubuntu 13.x and 14.x, respectively. The player is VLC but the built-in media player doesn't see any content either.  I loaded the DVD in a Windows computer and it plays just fine there, using VLC. I tried using handbrake to make a backup of it but Handbrake doesn't see any content.  Is it normal that Ubuntu can't play Disney DVDs? How can I get around this?  I'd like to rip the DVD to my harddisk; that's how we view all our other DVD's. Failing that, I'd at least want to be able to play the DVD on Ubuntu...

My machine can't play encrypted DVDs on a fresh install.  How do I add this capability?  Another useful bit of information would be what programs are best for playing DVDs, once I'm able to do so.  See the .  Will I be able to play DVD movies from ?


I was meeting a lot of people while I was working in London.  I met a lot of people while I was working in London.  What is the difference between them?  I'm not sure about these sentences.  How to clear them?  Please, explain it easily.

Non-native speakers often get confused about what the various tenses  and aspects mean in English. With input from some of the folk here I've put together a diagram that I hope will provide some clarity on the matter.  I offer it as the first answer to this question. Consider it a living document. Input is welcome, and good suggestions will be  incorporated into the diagram.    Nota bene: What this is not is a discussion of whether there are  more than two tenses in English. , to which this question is not intended to supply arguments one way or the other.  Here, the aim is to provide an overview of what constructions English-speaking people use for conveying information about actions referring to past, present, and future, and to provide it first and foremost to precisely the people who are likely to use "tense" as a catch-all term in their search, rather than to linguists who know better.  Breaking News There is now an excellent ELU blog article titled  . It is highly recommended reading.


i have an iMac 2020 and a late 2015 iMac. I wish to know if it’s possible to use the latter as target display monitor. and if yes, which cable should i buy? thanks

I have a Surface Pro 4 and an iMac (late 2019). I would like to connect my Surface Pro to the iMac to use the iMac screen as a second monitor.  Is that possible?  What are the requirements to use an iMac as a second screen?


All I remember is that the premise is that these old people put their consciousness into younger bodies, and they all have different symbols on their bodies denoting their role in society. I think the main character is a girl who has the "empty" symbol. At some point they all wake up from their pods (they're in space but they don't find out until later in the book). I wanna say that there's one character named O'Malley who is the politician/diplomat role. The kids take over the ship at some point and land it on some planet (I think this is where the first book ends and the second begins?) It is a series and sorry that this is all I remember, it's bits and pieces but hopefully someone knows what it is...

My dad read a book series that he recommended to me last year. Now that I am ready to start it, neither of us can recall the title. He said there were several in the series but he can't recall how many.   The book is about traveling to a new planet, presumably with the goal of colonizing it. The crew are clones who have no memory. I think the goal was for the older original versions of the clones to transfer their consciousness into the clone bodies to be able to live on the new planet but something goes wrong.   There is an indigenous species on the planet who are humanoid but have kangaroo like tails.   The clone crew has markings on them that they don't understand until late. Apparently they are markings to indicate status or role on the new world. The person who they voted as there leader, it turns out, is marked as a servant or slave class.


Good Morning   I need to decrease an object on edit mode so it gets to 60cm height, but when I use the scale tool, it is proportionally decreased. How can I solve this?  Thank you.

Im new to Blender but have some experience with 3dsmax. In blender, when i select some polys and try to scale them, i have no control on the amount and especially relative axis on which the scale would happen, where as with 3ds max i could scale restricted to x, y, z or any combination of using the handy widget. Is there a way to replicate this, or to get any control over the scale ?  thanks,


I know that when dealing with polymorphism in Java, you can have a different declared type for an object than the object type. For example:       Parent foo = new Child();    I mostly see it when the declared type is an interface such as:      Map<Integer,BigInteger> memo = new TreeMap<Integer,BigInteger>();       I see this a lot in peoples Java code. What is the benefit of declaring foo as a Parent when it is a Child object? I also understand that if we do this, foo can no longer call any methods that are not declared abstract or defined in Parent. What puzzles me is I see this done when we can have both the declared and actual type Child and still pass as an argument to methods which require a Parent parameter object. For example:      Child fooNew = new Child();     public void showObj(Parent o){         System.out.println(o); }     showObj(fooNew);   So what gives? In what circumstance would it be beneficial to have different declared and actual types for an object? My book says its important for generic programming but doesn't explain. I see it consistently used but with no clue why. And it even seems to have some drawbacks of its own.

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


I want to play Minecraft against my son with us each on a different PC where we can create our own worlds without any other interference from other users.  Is that possible, what do we need (I assume 2x PC minecraft accounts) and how do I do it?  Thanks

I would like to create a minecraft server for me and and my boyfriend to play on.  How do I set it up? Do I need any additional software? Do you have some links to walkthroughs or tutorials?  I have tried to set this up a few times but have failed every time.


So, here we have how my new prison currently looks. However, I ran into issues when it comes to keeping the prisoners to where they belong.  I have 3 cell blocks, the grey ones are currently open to min sec and med sec while i placed all the max sec into another block. I've built them a seperate canteen, a yard, common room, laundry and placed a shower head into each cell. I didn't want to build all these classrooms, chapels and so on just for the max secs, so I want them to be able to leave their block to enter them. But for some reason, the max secs can walk around the prison freely since I don't have a chance to restrict them to specific areas. I've tried to create small areas and make them minsec only or medsec only, but i need both, min and med, to be able to pass through those areas.  Basically, in the image, you can see where the max secs should be able to go, but not further. How can I do that?

How can I make sure that only low and medium security inmates are in a specific area? Is it possible to reverse the overlay you can set? It seems like you are only able to clear areas for low OR medium security prisoners, but sharing is not possible. The thing I want here is to make sure that max security prisoners are not in certain areas.


I have had a old partition of Ubuntu running 17.04 that I haven't booted to in ages. I finally booted back into it the other day and wanted to know how do I upgrade? The software updater doesn't work anymore. I assume because the software sources are taken down. How do I update the sources? And which one should I update them to to have a safe upgrade? Perhaps I could set my sources to 18.04 first and do that upgrade?  christopher@Chris-Gaming-Linux:~$ sudo apt-get update [sudo] password for christopher:  Ign:1 http://security.ubuntu.com/ubuntu zesty-security InRelease Err:2 http://security.ubuntu.com/ubuntu zesty-security Release   404  Not Found [IP: 91.189.91.38 80] Ign:3 http://us.archive.ubuntu.com/ubuntu zesty InRelease Ign:4 http://us.archive.ubuntu.com/ubuntu zesty-updates InRelease Ign:5 http://us.archive.ubuntu.com/ubuntu zesty-backports InRelease Err:6 http://us.archive.ubuntu.com/ubuntu zesty Release   404  Not Found Err:7 http://us.archive.ubuntu.com/ubuntu zesty-updates Release   404  Not Found Err:8 http://us.archive.ubuntu.com/ubuntu zesty-backports Release   404  Not Found Reading package lists... Done E: The repository 'http://security.ubuntu.com/ubuntu zesty-security Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://us.archive.ubuntu.com/ubuntu zesty Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://us.archive.ubuntu.com/ubuntu zesty-updates Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://us.archive.ubuntu.com/ubuntu zesty-backports Release' does no longer have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


According to electrodynamics, accelerating charged particles emit electromagnetic radiation.  I'm asking myself if the electron in an hydrogen atom emits such radiation. In , Murod Abdukhakimov says the total momentum of the electron is zero, hence it does not emit radiation. Could someone prove this statement ?  It may be an obvious question, but I can't figure out why the total momentum of the electron should always be zero, in any energy state.

I'm having trouble understanding the simple "planetary" model of the atom that I'm being taught in my basic chemistry course.   In particular,    I can't see how a negatively charged electron can stay in "orbit" around a positively charged nucleus. Even if the electron actually orbits the nucleus, wouldn't that orbit eventually decay?  I can't reconcile the rapidly moving electrons required by the planetary model with the way atoms are described as forming bonds. If electrons are zooming around in orbits, how do they suddenly "stop" to form bonds.     I understand that certain aspects of quantum mechanics  to address these problems, and that there are  of atoms. My question here is whether the planetary model itself addresses these concerns in some way (that I'm missing) and whether I'm right to be uncomfortable with it.


I've been using C# for three years to make games and I've played with various simulations where numbers sometimes get big and Int32 is not enough to store the value. Eventually even Int64 became insufficient for my experiments, it took several such fields (actually an array of variable length) and a special property to correctly handle such big numbers. And so I wondered: Is there a way to declare a numeric variable with unlimited (unknown beforehand) length so I can relax and let the computer do the math?  We can write any kind of number we like on paper without needing any special kind of paper. We can also type a lot of words in a text file without needing special file system alterations to make it save and load correctly. Isn't there a variable to declare a who-knows-how-long-it-will-be number in any programming languages?

When doing calculations on very large numbers where integral data types such as double or int64 falls short, a separate class to handle such large numbers may be needed.    Does anyone care to offer an efficient algorithm on how best to do this?


Context  So I am playing with the code related to  by adding some method references to it. The modified code is below  /**  * [https://stackoverflow.com/questions/299068/how-slow-are-java-exceptions]  *   * The original code is credited to   * [https://stackoverflow.com/users/15809/mecki] &  * [https://stackoverflow.com/users/581994/hot-licks]  *   */ public class ThrowableCost {     int value;      public int getValue() {         return value;     }      public void reset() {         value = 0;     }      // This one will regularly throw one     public void method3(int i) {         value = ((value + i) / i) << 1;         // i & 1 is equally fast to calculate as i & 0xFFFFFFF; it is both         // an AND operation between two integers. The size of the number plays         // no role. AND on 32 BIT always ANDs all 32 bits         if ((i & 0x1) == 1) {             throw new RuntimeException();         }     }      // Similar to {@link #method3} but not throw the newly created exceptions.     public void method5(int i) {         value = ((value + i) / i) << 1;         // i & 1 is equally fast to calculate as i & 0xFFFFFFF; it is both         // an AND operation between two integers. The size of the number plays         // no role. AND on 32 BIT always ANDs all 32 bits         if ((i & 0x1) == 1) {             new RuntimeException();         }     }      private RuntimeException e = new RuntimeException();      // Similar to {@link #method3} but throw the pre-created exception.     public void method6(int i) {         value = ((value + i) / i) << 1;         // i & 1 is equally fast to calculate as i & 0xFFFFFFF; it is both         // an AND operation between two integers. The size of the number plays         // no role. AND on 32 BIT always ANDs all 32 bits         if ((i & 0x1) == 1) {             throw e;         }     }      public static void main(String[] args) {         System.out.println("Running...");         ThrowableCost t = new ThrowableCost();          invokeWithTryCatch(t, t::method3, "method3");         invokeWithTryCatch(t, t::method5, "method5");         invokeWithTryCatch(t, t::method6, "method6");          System.out.println("Done!");     }      private static void invokeWithTryCatch(ThrowableCost t, Consumer c, String label) {         long l = System.currentTimeMillis();         int i;         t.reset();         for (i = 1; i < 100000000; i++) {             try {                 c.accept(i);             } catch (Exception e) {                 // Do nothing here, as we will get here             }         }         l = System.currentTimeMillis() - l;         System.out.println(String.format("%s took %d ms, result was %d", label, l, t.getValue()));     }  }  /**  * Similar to {@link java.util.function.Consumer} but avoid auto-boxing in our case.  */ interface Consumer{     void accept(int i); }   The output is  Running... method3 took 30088 ms, result was 2 method5 took 29948 ms, result was 2 method6 took 6298 ms, result was 2 Done!   As you can see the execution time of method6 is around 6000 ms.   However, if I    invoked the method6 alone (by commenting out other invokeWithTryCatchs) OR invoked the method6 first (by swapping order of invokeWithTryCatchs) OR invoked the method6 via instance t instead of  c inside of invokeWithTryCatch   then the execution of the method6 is much shorter (i.e: around 700 ms)   Question Why does the order of invokeWithTryCatchs impact on the execution time of method6 in this approach ?  Note I tried with both JDK8 and JDK11.

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


I was wondering is there a limit to the amount of reputation points one question can receive and if not, what the highest you have ever seen or heard of?

On Stack Exchange, users may gain a certain level of reputation.  What does reputation do? How can a user gain or lose reputation?   See also   in the Help Center  - Maximum amount of votes a user can use in a day and reputation requirements to vote.  - How to get an exact overview of the actions that got you your reputation.  - A full list of all privileges granted at each reputation level on all sites.


Does anybody know of any physicists or mathematicians who have put forward a theory to everything, for which this mathematical theory would explain all physical phenomena in the universe in one equation?

Some time ago, I read something like this about the issue of "a final theory" in Physics: "Concerning the physical laws, we have several positions as scientists  There are no fundamental physical laws. At the most elementary level, the Universe/Multiverse is essentially chaotic and anarchical. There are no such laws.  There are a continuous sequence of more and more precise theories, but there is no a final theory. Physics will be always evolving from one approximate theory to another bigger and more accurate. In the end, we will be also able to find a better theory and additional levels of complexity or reality.  There is a final theory explaining everything, and we will find if and only if: i) We are clever enough to find such a theory. ii) We make good and sophisticated enough mathematics. iii) We guess the right axioms/principles/ideas. iv) We interpretate data correctly and test the putative final theory with suitable instruments/experiments. "   Supposing 3) is the right approach... Question: How could we prove the mere mathematical existence of such a theory? Wouldn't it evade the Gödel's incompleteness theorem somehow since, as a Theory of Everything, it would be explain "all" and though it should be mathematically self-consistent? How could a Theory of Everything be a counterexample of Gödel's theorem if it is so, or not? Note: The alledged unification of couplings in supersymmetric theories is a hint of "unification" of forces, but I am not sure if it counts as sufficient condition to the existence of a final theory. Complementary: Is it true that Hawking has changed his view about this question? SUMMARY: 1') Does a final theory of physics exist? The issue of existence should be tied to some of its remarkable properties (likely). 2') How could we prove its existence or disproof it and hence prove that the only path in Physics is an infinite sequence of more and more precise theories or that the Polyverse is random and/or chaotic at the most fundamental level? 3') How 1') and 2') affect to Gödel's theorems? I have always believed, since Physmatics=Physics+Mathematics (E.Zaslow, Clay Institute) is larger than the mere sum that the challenge of the final theory should likely offer so hint about how to "evade" some of the Gödel's theorems. Of course, this last idea is highly controversial and speculative at this point.


Suppose that the series $\sum_{n=1}^\infty a_n$ is conditionally convergent. Prove that the series $\sum_{n=1}^\infty n^2a_n$ is divergent.    How should I start to prove this? I have absolutely no idea how to go about solving this problem. Thanks in advance!

Ratio and root tests won't help. And I can't use the comparison test because $ |a_n| $ is not necessarily smaller than $ n^2a_n $.   Can I use limits? We know:    $\lim\limits_{n \to \infty} a_n = 0 $ $\lim\limits_{n \to \infty} |a_n| \ne 0 $   And we need to prove:    $\lim\limits_{n \to \infty} n^2a_n \ne 0 $   Any ideas/hints?


I know this has probably been beaten to death, but there really needs to be a way to remove yourself from posted content. I understand deleting content has its issues, but certainly you should be able to transfer something you posted to an Anonymous account.   I'm really going to open myself up to trolls here, but not being able to delete things you posted is a major issue for the new careers feature. I'm not talking about stupid questions / answers I've posted so much as smart ass remarks / troll posts. You will probably say that one deserves to have their inflammatory comments stay attached to their name. I think that everyone has bad moments though, and there should be a way to publicly delete it. Not having delete forces people to create new accounts just to use the careers feature.  Edit: I just want to make it clear that I agree you shouldn't post anything you don't stand by. I'm saying though there should be some recourse for when you did.

The Creative Commons FAQ      Third, if the licensor does not like how the material has been modified or used, CC licenses require that the licensee remove the attribution information upon request [...]  in 4.0, this also applies to the unmodified work.   How do I remove / dissociate my name from a post, in accordance with this clause?  Also, what are the effects of having my post dissociated from my account?  Finally, how will dissociation requests be handled for posts licensed under earlier versions of the license, which do not require dissociation upon request in all cases?


I'm studying the chapter $10$ of Gathmann's note on algebraic geometry and there is a proposition that I don't understand.  Proposition 10.11. (Affine Jacobi criterion) Let $a \in X$ be a point on an affine variety $X \in \mathbb A^n$, and let $I(X) = \langle f_1, \ldots, f_r\rangle$. Then $X$ is smooth at $a$ if and only if the rank of the $r \times n$ Jacobian matrix $$\left(\frac{\partial f_i}{\partial x_j}(a)\right)_{i,j}$$ is at least $n - \text{codim}_X(a)$. (...)  The thing that bothers me is that the generators of the ideal $I(X)$ are not necessarily unique (right?), how can we conclude this statement? Could the Jacobian matrix of some generators satisfy the property while that of other generators does not?

This is a statement made in Hartshorne Chpt 1, Sec 5.  Let $Y\subset A^n$ be an affine variety. Let $\{f_i\}$ be a set of generators of ideal $I(Y)\subset k[x_1,\dots, x_n]$. Let $p\in Y$. Define $r=\mathrm{rk}(\frac{\partial f_i}{\partial x_j}|_p)$. Then $p$ is smooth iff $r=n-\dim(Y)$.   Q: How does one see this definition of rank is independent of the choice of generators? I guess he did not mention tangent space is isomorphic to $m_p/m^2_p$ at this part and I cannot use this intrinsic definition.


tldr :ok so I have a mix shader between glossy bdsf and principled bsdf on a mesh, and there is a part of the mesh I do not want glossy bdsf on, is there a way to control which parts of a mesh a shader is applied on? more details : i have a hair particle system on the object, and i do not want the glossy bdsf to show up under the hair, and i think there is enough hair and do not want to add more to "fix" the problem.

How do you add more than one material to a mesh?   I have tried adding two materials to the object, and then assigning one of the materials to a vertex-group, but I could not find a place to assign it.  I am making a striped bouncy ball that I want to deform, so adding a different material by separating the mesh into different objects would not be ideal.


I'm just starting to create new theme and i'm new to code. I'm stuck in customizing the post thumbnail code, i tried add   <?php previous_post_link(get_the_post_thumbnail(get_previous_post(), array(                         'class' =>  'rounded-lg object-cover'            )) . '
%link
',            '%title',false    ); ?>   but it doesn't seem to work. did my array mistakenly placed in the code?

I'm using post thumbnails to link to a page.  Is it possible to add a class name to the post thumbnail image.
<a href="<?php the_permalink(); ?>" ><?php the_post_thumbnail(); ?>


I have seen many cases where my possible question would automatically stand as a duplicate of an older one that seems to have answers, but these are bad, old, or just "no" answers providing a workaround, or trying to teach the OP about what it should be asked instead, etc.  Should I ask a new question and explain that it shouldn't be closed as duplicate although it looks like one?  Should I downvote all the answers I don't like?

I've come across this problem recently when trying to find a solution to a problem on Stack Overflow. It was a common question to which there were already literally dozens of highly rated answers.  In my view, these answers were not good, or did not address the question (in this case the solutions simply didn't work for me).  I have gone about this by posting my own question, outlining why the answers didn't work, and hoping for a response. Is this how things should be done? For anyone interested, here is my new question:


I making a digital sign for a restaurant in Blender. The theme is winter and I animated falling snow and make stacking snow on the ground/floor(plane) and the font. But I got the problem with the shadow catcher. I am using sun for the the lighting type and i rendered by Eevee but the shadow doesn't show in rendered as like in the view port. I tried to click every "shadow"- related boxes but it never worked. And I attached my file in this link.

I want to know is there a way to render Shadows only in Blender's new EEVEE Render Engine. I want my objects in a separate collection and a ground plane on a separate collection(to receive shadows from the objects collection).I want to render the shadows only and not the objects.


Are you sure the following is true or not.:  $(0.\overline{9}=1 )$  If proven true or false is not.Thank

I'm told by smart people that $$0.999999999\ldots=1$$ and I believe them, but is there a proof that explains why this is?


I want to replace a number with another number which is stored in a variable. How can this be done? Thanks in advance.

I want to replace the 5th line of multiple text files (file1.txt,file2.txt,file3.txt,file4.txt) with the string " Good Morning " using a single terminal command.  All the text files are located on my ~/Desktop.  Note: My desktop consists of 6 .txt files.I want to apply the change to above mentioned 4 text files only.


I want to overlay "top-container" div over "image" div, even though I used Z-index it is not working.   body {   margin: 0;   padding: 0;   text-align: center; }  .image {   background-image: url("pic/back.jpg");   z-index: -1;   height: 30rem;   background-size: 100%;   position: relative;   margin: 0; }  .top-container {   font-family: "Dancing Script", cursive;   z-index: 2;   position: absolute;   margin: 0; }  .top-container h1 {   margin: 0;   font-size: 3rem;   color: #00b894; }  .top-container h2 {   font-size: 2rem;   color: #0984e3; }  <link href="https://fonts.googleapis.com/css2?family=Dancing+Script:wght@600&display=swap" rel="stylesheet" />

Hi
There

I'am

Thiru

    I am just a beginner so, I need some explanation for the solution. please kindly provide me with the concept behind the solution to the above problem.

I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


I have a new computer with a Asus P5QL Pro motherboard and wanted to plug my old HP DeskJet 950C printer into it only to discover that the motherboard has no LPT/Parallel port.  What is the best solution for this?    is there a LPT-to-USB adapter? do I need to buy an LPT PCI board?

How do you install windows 10 drivers for an old designjet 430 hp plotter?  It has a parallels port (LPT port), no USB.   I haven't been able to find Windows 10 drivers for it.


I've found many questions here regarding this 'feature' and many answers explaining how it works, but none showing any 'philosophical' concept behind it. i.e., why is it here? Is it helping to make site better?  For example, just now I made a downvote, retracted it to think a bit more, left a comment with explanation and tried to downvote again. No game. And this is not the only real-life situation when value of this 'feature' is doubtful. There're plenty on this meta.  So, what was the primary reason to introduce it? A flow of people who change all their votes on daily basis?

I downvoted  and now really can't say why, so I wanted to remove my downvote. However, I get the message:  You last voted on this question yesterday Your vote is now locked in unless this question is edited  Why is this? I don't think I voted on it multiple times, and even when I did, I can change my mind, can't I?


Is there any difference between the use of double quotes to single quotes in Python?   "A string with double quotes" 'A string with single quotes'   Are they identical? Are there differences in how python interprets these strings?

According to the documentation, they're pretty much interchangeable.  Is there a stylistic reason to use one over the other?


I looked over the "your question may already be answered" suggestions box and didn't see anything that fit, but I've been known to miss those before so apologies in advance if this has been asked before (I imagined it must have been, but see nothing). What is the correct action when something like this happens:   A question is posted to SO.  You see a few missing lines of code that are the problem, so you post an answer saying so.  OP takes the code you've suggested and copies it into their question, along with something like "EDIT: I added this new code and it fixed part of the problem but it still doesn't work."    At this point the answer doesn't fit the question anymore; on the surface the answerer looks pretty stupid for saying "add these lines" when the lines were already in the question (as far as new viewers can tell, anyway). I commented to the OP and asked a follow-up question to see if I could figure out the rest of the problem, but no dice on that just yet and in the meantime the answer is sitting there looking silly. So, what's the proper procedure in this case? Delete the answer? Rollback the question edit? Leave it sitting there as is until we get to the bottom of the problem? (What if it turns into one of those rabbit-hole questions where the problem keeps changing with every fix?) Just leave it alone and forget about it?

I'm not sure if there's already an existing term for this, so I'm inventing my own. (tl;dr: I call them "chameleon questions" because they change every time you submit or edit an answer.  If you're already intimately familiar with the phenomenon, please skip past the first set of bullet points to where I ask for recommendations.)  I think many of us have experienced this on occasion:  You open up a narrow-looking question, usually dealing with some specific error message.  The question probably contains a snippet of sloppy but not quite awful code; code indicating that the author, typically a new/low-rep user, possibly a , doesn't really know what they're doing.  I'm not trying to be condescending here, they're probably very intelligent and hardworking, but in this specific case, they're clearly in way over their head.  However, as a question, it's not really too bad.  The goal and problem are both clearly stated.  The code is formatted (sort of).  Mort was polite and checked their spelling.  The question looks answerable, although from a rep perspective* it's an obvious dead-end, it's had maybe 3 views in the past 30 minutes.  So you decide, you know what, this person took the time to write up the question properly, they deserve an answer, put on your good citizen hat and throw them a bone.  You slog through the ugly code, find the offending line, direct their attention to it and explain why it's wrong and how it needs to be fixed.  Later, they leave a comment saying that yes, that was indeed the problem and your answer helped them fix it (great!).  Oh, but, now there's another problem (uh-oh...). Something else is broken.  After letting out a long sigh, you read the comment and/or edited question, roll up your sleeves, and write up Take 2, hoping that's the end of it.  And of course it's not the end.  Now maybe the error is gone, but it's not doing what it's supposed to.  If you're anything like me, your patience is now starting to wear thin. It's lousy code and you didn't volunteer to help them rewrite their whole app.  And of course, the question still only has 12 views, and nobody has upvoted either the question or your answer, including the person you're helping, so this is turning out to be a genuinely thankless task in all respects.  Welcome to "Family Tech Support", Web 2.0 Edition.   * Which is of course just an arbitrary number that none of us care about. Not really, anyway. Not very much, at least.  So, here's where I get to my question.  At this point, do you:  Leave a comment, stating as politely as possible that you've done your best to help them answer the original question they asked, and if they have a new problem then they should start a new question?  (I did this once, and actually ended up with an accept, but I felt kind of guilty afterwards, I don't think anybody answered their 2nd question).  Bite the bullet and edit your answer a 3rd, 4th, 5th time, however many times it takes to resolve their issue, knowing full well that they may not even remember to accept the answer once you're done? (I may work for free on SO, but that doesn't mean my time is worthless.)  Just abandon the question, hoping that it will force Mort to start thinking for himself?  Something else?   I've tried all three of the above and none of them ever quite feel right. I do want to help, but at the same time there are a lot more "lucrative" questions I could be answering. And I don't mind spending a lot of time on an answer either, if the question is interesting or important to me, but debugging is dull work. I'd prefer not to reference specific questions here; I'm pretty sure that this is a shared experience, and my objective isn't to point fingers at "misbehaving" members.  I'm more looking for some practical advice on how to dig myself out of these pits of despair. Anybody have any other ideas?


I'm looking for a method to have bash colorize the output from a command based on what stream it was written to the terminal from. Is there any way to get it to colorize per stream?  Like for example  stdout -> regular color stderr -> red program created streams that write to the terminal -> blue

I want to set my terminal up so stderr is printed in a different color than stdout; maybe red. This would make it easier to tell the two apart.  Is there a way to configure this in .bashrc? If not, is this even possible?    Note: This question was merged with  that asked for stderr, stdout and the user input echo to be output in 3 different colours. Answers may be addressing either question.


I saw someone's iphone5 whatsapp notification pop up with only the whatsapp badge and the word "message" but I can't figure out how to do that on my iphone5

Today I updated to version 2.18.52 & I can’t see the names of the people who send me a message. The only thing I see is the WhatsApp logo and the word “message”.    I can’t also see the status my friends posts, they all look black. I uninstalled the app, reset my phone & nothing seems to work so far.


Light travels at its maximum speed in a vacuum. But when it enters a medium such as glass, air, water, etc. it slows down. What is actually happening to the photons as they pass through the medium? Are they being absorbed by the atoms, exciting the electrons and after some time somehow being re-emitted in the same direction? Are they travelling at vacuum speed between atoms?

So light travels slower in glass (for example) than in a vacuum. What causes light to slow down? Or: How does it slow down? If light passes through the medium, is it not essentially traveling in the "vacuum" between the atoms?


I want to use the following line in a poem:     Will he roll the dice, and follow it to Vegas?   A couple of things to note; firstly, obviously I'm using "roll the dice" in both a figurative/idiomatic sense (as in taking a risk), and in a somewhat more literal sense (painting the image of the person actually following the dice that have been rolled to Las Vegas).   That being said, my confusion here is if I can get away with using "follow it" or if I need to say "follow them" .... As I've read online "dice" traditionally refers to more than one die (i.e., the plural of die), but in the modern usage, "dice" can also be used to refer to the singular (i.e., just one die). So, it seems like if I was referring to the image of just one die, then the way I phrased it could be correct. However, the image I'm trying to paint is the one usually associated with the phrase "roll the dice" (i.e., rolling two dice)... So could "follow it" still be considered acceptable in this sense... or would I need to use "follow them"?... And if not referring to the dice themselves, could using, could the "it" be taken to refer to the act of rolling the dice, or would that not work either?

I want to use the following line in a poem: "Will he roll the dice, and follow it to Vegas?"   A couple of things to note; firstly, obviously I'm using "roll the dice" in both a figurative/idiomatic sense (as in taking a risk), and in a somewhat more literal sense (painting the image of the person actually following the dice that have been rolled to Las Vegas). That being said, my confusion here is if I can get away with using "follow it" or if I need to say "follow them" .... As I've read online "dice" traditionally refers to more than one die (i.e., the plural of die), but in the modern usage, "dice" can also be used to refer to the singular (i.e., just one die).   So, it seems like if I was referring to the image of just one die, then the way I phrased it could be correct. However, the image I'm trying to paint is the one usually associated with the phrase "roll the dice" (i.e., rolling two dice)...   So could "follow it" still be considered acceptable in this sense... or would I need to use "follow them"?... And if not referring to the dice themselves, could using, could the "it" be taken to refer to the act of rolling the dice, or would that not work either? Thanks so much in advance!!


I ran into some problem while doing some work... let num = 9.340 / 10;  console.log(num) // gives this number 0.9339999999999999, instead of 0.934  I know how to solve this problem with toPrecision() or some math library, but that is not the problem. I want to understand why this is happening... I know that mathematically this is correct, just as 0.9999999... can be proven to equal 1, but common sense tells me that it is more logical that 0.934 is displayed... And what is more mindblowing is that (0.934 == (9.34 / 10)) returns false?? Please, if someone can explain this behaviour to me I would be very thankful, cheers :)

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Hello guys i like to know what's the difference in the bash i used ls without ` ` in bash so my program did not work and when i add ` ` it  works, what's the object of it   for i in `ls` do     if [ -d $i ]     then         echo $i         let j=$j+1     fi     if [ -f $i ]     then         echo $i         let k=$k+1     fi     if [ -x $i ]     then         echo $i         let l=$l+1     fi done echo "Il y a $j répertoires, $k fichiers et $l exécutables dans $rep"

I saw the following syntax in a bash script:   >$(command) &   I know that the ampersand & at the end makes a command run in the background, but I have never seen it in combination with the dollar sign plus the brackets around the command.  What does it do?


Occasionally I receive an error report from Ubuntu with the option to send in the details of the error. However, if the error was generated from a non-official package (local installation or PPA) I cannot just click submit to send in the error.  How can I copy all the error details so that I can manually submit them to the appropriate project?

An app just crashed and I want to copy the error message and paste it into a search engine to hopefully find a solution.  Unfortunately the error dialog does not allow me to copy/paste anything:    In particular the stack trace, which is very long. Typing manually is slow and unreliable.  Maybe the same details can be copied from somewhere else?  Note: Similar to  but with more details. If one must be closed as a duplicate, despite being newer I believe this one is more useful. It is de-facto more popular: 200 views there, 42k views here.


I need to extract out this text "start_time":"2018-08-05T17:41:29.933Z" form this string:  BLAH text BLAH text "start_time":"2018-08-05T17:41:29.933Z" blah TEXT BLAH text  I tried this: \[\"start_time\":\"(.*)\"\]  But it did not work. What am I missing here?  Thanks!

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


I have 2800 files, all of whose names start with a four-digit number followed by " - ", and I want to delete all those leading numbers from all the files, leaving only the alphanumeric file names1.  How can I do this? ________________ 1 Some of the filenames contain numerals after the " - ".

I've got a bunch of files named with a the pattern 99 - DescriptiveName.txt and I'd like to remove the number from the front so I just have DescriptiveName.txt.  How can I do this? Can I do it from the command line or is there a utility that can do this?


I just wish to confirm if my understanding is correct for the following problem:  if there are 5 women and 5 men, how many possibilities exist to form a committee of 3 women and 2 men. so i have computed this problem as below  5C3 x 5C2 = 100 possibilities.   is this correct?

A committee of 6 people is to be chosen from a group consisting of 7 men and 8 women. If the committee must consist of at least 3 women and at least 2 men, how many different committees are possible?  The answer given in the text is $\binom{8}{3} \binom{7}{3} + \binom{8}{4} \binom{7}{2} = 3430$. I understand this line of thinking--first count all the ways we can choose 3 of the 8 women and 3 of the 7 men. Then, add to this all of the we can choose 4 of the 8 women and 2 of the 7 men.  I thought about this question a bit differently, however, and am failing to see where my line of thinking is flawed. This is how I performed the calculation:  $$\binom{8}{3} \binom{7}{2} 10 = 11760$$  In other words, we choose 3 women and then 2 men. Then, we are left with 10 other choices, the gender of whom is irrelevant. What am I doing wrong?


I have 8 GB RAM and a 8 GB swap partition and I set vm.swappiness to 90 in /etc/sysctl.conf (and verified that it's used with the sysctl command at runtime). The system uses 50 % of RAM and 40 % of swap and this situation is approximately the same after running sudo swapoff -a && sudo swapon -a and a delay of minutes. Also I see that swapping of ca. 100 MB occurs regularily at runtime.  I don't understand why the memory isn't filled up to 90 % as suggested by vm.swappiness.  I experienced with issue with Linux 4.4.0-22 and 4.5.7 on Ubuntu 16.04.  $ cat /proc/meminfo  MemTotal:        8030020 kB MemFree:          220724 kB MemAvailable:    4418060 kB Buffers:           86456 kB Cached:          4090160 kB SwapCached:       184660 kB Active:          3779408 kB Inactive:        2730596 kB Active(anon):    1736480 kB Inactive(anon):   955376 kB Active(file):    2042928 kB Inactive(file):  1775220 kB Unevictable:       62848 kB Mlocked:           62848 kB SwapTotal:       8462332 kB SwapFree:        5576576 kB Dirty:             40332 kB Writeback:             0 kB AnonPages:       2312568 kB Mapped:           315084 kB Shmem:            351016 kB Slab:            1039608 kB SReclaimable:     937796 kB SUnreclaim:       101812 kB KernelStack:       15744 kB PageTables:        53896 kB NFS_Unstable:          0 kB Bounce:                0 kB WritebackTmp:          0 kB CommitLimit:    12477340 kB Committed_AS:   10436316 kB VmallocTotal:   34359738367 kB VmallocUsed:           0 kB VmallocChunk:          0 kB HardwareCorrupted:     0 kB AnonHugePages:    448512 kB CmaTotal:              0 kB CmaFree:               0 kB HugePages_Total:       0 HugePages_Free:        0 HugePages_Rsvd:        0 HugePages_Surp:        0 Hugepagesize:       2048 kB DirectMap4k:      369540 kB DirectMap2M:     7874560 kB

I need a step-by-step, simple and easy way to configure swappiness.


Often when I am writing an answer in the Android app I need to refer back to the question to confirm a point I have read, so I click the "back to question" button at top right.  When I go back to the question a button "edit your answer draft" appears at the bottom of screen as expected.   Clicking this button often takes me to an empty answer form with my draft work lost. A further "back" click takes me back to the question with no "edit answer draft" button.  Am I doing something wrong or is this a bug in the Android app?  Equipment: Samsung Galaxy S5 phone, Android 5.0

The Edit Answer Draft button is broken.    Press Back with text in an answer box. The Edit answer draft bar does not appear.     Seems like an onBackPressed() issue.  Also:   Press ← with text in the answer box The bar appears. Click the bar The answer box is blank.   Seems like the answer isn't properly carried between the Fragments.  Either way, you lost everything you wrote.  Can somebody test this? And especially without a confirm dialog, it is a brush of the finger to lose a long post of code or something.   I hope this report will help because I like the app (I'd say 4/5 stars) but the bugs are preventing a solid 5 stars.   Stack Exchange 1.0.73 Samsung Galaxy S II Skyrocket I727 Android 4.1.2


for(int i=0;i<n;i++)  {   }  vs for(int i=0;i<n;++i)  {   }  Both these loop run n times but we know that ++i and i++ are different. So can anyone explain what is happening in backend in gcc compiler using cpp? Thanks in advance

Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?


I have a problem with in-line code formatting here:  I want to make two different in line code in single comment. What I'm doing wrong? This is how it looks currently:  My green/red/blue markers shows what to focus on:  In edit mode without additional spaces:  In edit mode with additional spaces:

Tried to add a comment to a post today, which ended up looking rather weird. What I had typed was:  On windows I believe you need to use `\` instead of `/`   As you can see in the first comment to this question, I don't exactly end up with what I thought I would... What's going on here?  Tried various combinations of double \\ and double `` (which seems to be impossible to have in an inline code thing...?), but couldn't get a good result. Ended up putting a space after the slash, which at least made it readable. Problem then was that the space between the inline code and the word "instead" seems to disappear O.o


The problem is to find the number of binary words of length of $n$, with $m$ 1s and at least $k$ 0s between 1s.  I have been thinking about this for a few days now, but I am unable to simplify it thus far.  I tried to determine the positions of the first and last 1s, but that led me to a similar problem (although on a smaller scale, so perhaps this is a correct approach).  However I believe that there is a simpler approach. Could anyone provide some guidance?  EDIT: Maybe I should consider the 100... as a single unit, this makes it a lot simpler. Is it correct though?

Number of ways to select $K$ people from $N$ people (who are aligned in a line)  such that at least $r$ people are there in between them  Ex: I want to select 3 people from 10 people (who are aligned in a line) such that at least 2 people should be there between the selected people   May I know the resources for learning this type of problems , also what is the solution if people are arranged in circular manner


I'm having some trouble changing the colors of parts of an equation in Beamer, with "math text" being set. The following MWE demonstrates the example:  \documentclass{beamer} \usepackage{color} \setbeamercolor{math text}{fg=blue}  \begin{document} \begin{frame}{Frame}     $x \alert{\cong} y \alert{=} z$ \\     $x \textcolor{green}{\cong} y \textcolor{green}{=} z$ \\     $x {\setbeamercolor{math text}{fg=green}{\cong}} y {\setbeamercolor{math text}{fg=green}{=}} z$ \end{frame} \end{document}   I would expect both symbols in the first and second line to get colored. However, for some reason, \cong is not colored, but = is. Is there some way to make coloring work reliably with all math symbols?  I found another Stackexchange question () where people suggested the code I used in the third line - which, confusingly, works for \cong, but not for =.  For now, I replaced \cong by \stackrel{\sim}{=}, but really that's just a work-around, and if this ever happens with a symbol I cannot reconstruct otherwise, I'll be in trouble.

I have a presentation with the color for math changed to blue:  \setbeamercolor{math text}{fg=black!15!blue}   Everything looks nice, until I want to recolor part of an equation:  \begin{align*}    x\ y\ z &: A  \color{red}\longleftarrow \text{Assumptions}\\    \hline    x &\in \color{red}\underbrace{[x,y,z]}_{\text{Goal}} \end{align*}   Then it just goes bananas: half of the left arrow is printed in blue, and the brace is totally printed in blue.  Any help will be appreciated.  The entire code:  \documentclass{beamer} \setbeamercolor{math text}{fg=black!15!blue}  \begin{document} \begin{frame}    \begin{align*}       x\ y\ z &: A  \color{red}\longleftarrow \text{Assumptions}\\       \hline       x &\in \color{red}\underbrace{[x,y,z]}_{\text{Goal}}    \end{align*} \end{frame} \end{document}


Is there a simple way to  move a point to an exact coordinate (do not intend to create a new point but move an existing point)?  Something like, write the coordinates and move a selected point for that coordinate.

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000).   How should I do it using QGIS?


Googling didn't help in this case, I'm posting here. I was wondering if there is a way to find how much memory a module takes when imported into Python?   Thanks

I want to know how to get size of objects like a string, integer, etc. in Python.  Related question:   I am using an XML file which contains size fields that specify the size of value. I must parse this XML and do my coding. When I want to change the value of a particular field, I will check the size field of that value. Here I want to compare whether the new value that I'm gong to enter is of the same size as in XML. I need to check the size of new value. In case of a string I can say its the length. But in case of int, float, etc. I am confused.


I am in undergraduate. I wish to apply for scholarship to do PHD in the USA. Will publishing a paper in this conference () help me get funding? It does not seem like a very reputable conference. However, I am not sure if my paper will be accepted in top tier conferences. So, is this conference 'better than nothing'? How much can a paper here help me? thank you.

I recently received an invitation to a conference and I'm trying to determine how reputable it is. Is there a good way to go about this?


Recently our scanner identified several vulnerabilities with Apache tomcat. The latest version in Ubuntu 20.04 is tomcat9 9.0.31-1ubuntu0.1 There are several CVE's that are fixed only in higher versions  9.0.35: CVE-2020-9484 -  9.0.36: CVE-2020-11996 -  9.0.37 - Apache Tomcat 9.0.0.M1 < 9.0.37 Multiple Vulnerabilities (didn't find CVE) 9.0.38 - Apache Tomcat 8.5.x < 8.5.58 / 9.0.x < 9.0.38 HTTP/2 Request Mix-Up (didn't find CVE) 9.0.40 - Apache Tomcat 9.x < 9.0.40 Information Disclosure (didn't find CVE)  Unfortunately, I can't upgrade due Ubuntu 20.10 due to client requirements Please advice when we should expect newer version with Focal repositories. Thanks.

Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical


My understanding of complex numbers is that it is the use of an extra axis of dimension. By plotting a signal on polar axis, the real number, x, is the sine of the signal, and the imaginary number, y, is the cosine of the signal. This understanding is derived from its use in the fourier transform. (By this understanding, one could take the cosine of a value to get its imaginary component, so my understanding it limited as it doesn't explain the logic behind √(−1)=i.) So, I have the question, is it possible to have three value complex numbers?

Since there are  complex numbers (2 dimensions) and quaternions (4 dimensions), it follows intuitively that there ought to be something in between for 3 dimensions ("triernions").   Yet no one uses these. Why is this?


Can anyone could point me in the right direction for installing Ubuntu (the latest version...14.something) to dual boot alongside my existing  MAC OS 10.9.2?  I just want to make sure I do it right. Thanks!

On my Macbook Air 10.9.2 without crashing the current setup, how can i install as dual boot: Ubuntu 14.04 LTS ? (can anyone please advise some step by step please)