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How to abort a running program in MATLAB?
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Closed 7 years ago.
I write a long running script in Matlab, e.g.
tic;
d = rand(5000);
[a,b,c] = svd(d);
toc;
It seems running forever. Becasue I press F5 in the editor window. So I cannot press C-Break to stop in the Matlab console.
I just want to know how to stop the script. I am current use Task Manager to kill Matlab, which is really silly.
Thanks.
Matlab help says this-
For M-files that run a long time, or that call built-ins or MEX-files that run a long time, Ctrl+C does not always effectively stop execution. Typically, this happens on Microsoft Windows platforms rather than UNIX[1] platforms. If you experience this problem, you can help MATLAB break execution by including a drawnow, pause, or getframe function in your M-file, for example, within a large loop. Note that Ctrl+C might be less responsive if you started MATLAB with the -nodesktop option.
So I don't think any option exist. This happens with many matlab functions that are complex. Either we have to wait or don't use them!.
If ctrl+c doesn't respond right away because your script is too long/complex, hold it.
The break command doesn't run when matlab is executing some of its deeper scripts, and either it won't log a ctrl sequence in the buffer, or it clears the buffer just before or just after it completes those pieces of code. In either case, when matlab returns to execute more of your script, it will recognize that you are holding ctrl+c and terminate.
For longer running programs, I usually try to find a good place to provide a status update and I always accompany that with some measure of time using tic and toc. Depending on what I am doing, I might use run time, segment time, some kind of average, etc...
For really long running programs, I found this to be exceptionally useful
http://www.mathworks.com/matlabcentral/fileexchange/16649-send-text-message-to-cell-phone/content/send_text_message.m
but it looks like they have some newer functions for this too.
MATLAB doesn't respond to Ctrl-C while executing a mex implemented function such as svd. Also when MATLAB is allocating big chunk of memory it doesn't respond. A good practice is to always run your functions for small amount of data, and when all test passes run it for actual scale. When time is an issue, you would want to analyze how much time each segment of code runs as well as their rough time complexity.
Consider having multiple matlab sessions. Keep the main session window (the pretty one with all the colours, file manager, command history, workspace, editor etc.) for running stuff that you know will terminate.
Stuff that you are experimenting with, say you are messing with ode suite and you get lots of warnings: matrix singular, because you altered some parameter and didn't predict what would happen, run in a separate session:
dos('matlab -automation -r &')
You can kill that without having to restart the whole of Matlab.
One solution I adopted--for use with java code, but the concept is the same with mexFunctions, just messier--is to return a FutureValue and then loop while FutureValue.finished() or whatever returns true. The actual code executes in another thread/process. Wrapping a try,catch around that and a FutureValue.cancel() in the catch block works for me.
In the case of mex functions, you will need to return somesort of pointer (as an int) that points to a struct/object that has all the data you need (native thread handler, bool for complete etc). In the case of a built in mexFunction, your mexFunction will most likely need to call that mexFunction in the separate thread. Mex functions are just DLLs/shared objects after all.
PseudoCode
FV = mexLongProcessInAnotherThread();
try
while ~mexIsDone(FV);
java.lang.Thread.sleep(100); %pause has a memory leak
drawnow; %allow stdout/err from mex to display in command window
end
catch
mexCancel(FV);
end
Since you mentioned Task Manager, I'll guess you're using Windows. Assuming you're running your script within the editor, if you aren't opposed to quitting the editor at the same time as quitting the running program, the keyboard shortcut to end a process is:
Alt + F4
(By which I mean press the 'Alt' and 'F4' keys on your keyboard simultaneously.)
Alternatively, as mentioned in other answers,
Ctrl + C
should also work, but will not quit the editor.
if you are running your matlab on linux, you can terminate the matlab by command in linux consule.
first you should find the PID number of matlab by this code:
top
then you can use this code to kill matlab:
kill
example:
kill 58056
To add on:
you can insert a time check within a loop with intensive or possible deadlock, ie.
:
section_toc_conditionalBreakOff;
:
where within this section
if (toc > timeRequiredToBreakOff) % time conditional break off
return;
% other options may be:
% 1. display intermediate values with pause;
% 2. exit; % in some cases, extreme : kill/ quit matlab
end
Related
Getting started with Pascal here. I wanted to write a simple program that first clears the terminal window and then reads user input. The first result of searching for clearing the screen showed the ClrScr procedure. Using it gets the job done but ClrScr needs Crt which results in a new problem. Terminating the program using Ctrl + C does not work. Searching online again, I found that Crt takes over I/O. I have been looking for alternative to ClrScr but haven't really found anything so far.
So how can I clear terminal while still being able to terminate the program using Ctrl + C. Also how can I terminate the program in the current case using Crt?
Current Code:
program Test;
uses Crt;
var
x : integer;
begin
read(x);
end.
So far the solutions I have seen online and the ones suggested in the comments for keeping CRT just make it troublesome and unnecessary makes the program complex. So for now I have decided just to discard it totally.
The workaround I have found now is to use unix.fpsystem with the clear command which gets the job done just fine.
I have a problem which I think might be solvable with a batch file, but I've only used batch files once or twice and don't know enough to try and solve this on my own. For context I'm running Windows 10 Home Edition, and have some programming experience, though it is primarily mathematical, i.e. R and MATLAB.
The problem is this: I have two programs, in this case Spotify and Toastify, which run together, with Toastify running in the background. I'll refer to them as S and T, respectively. If I run T, S runs as well, but if I close S, T remains running in the background. For reasons of convenience, I would rather that closing S also close T, so that when I want to use them again later I need only reopen T rather than checking if it's still running in the background, because T doesn't let you run multiple instances.
I'm wondering if there is an easy way to write a batch file (or something else if this isn't a good approach) that will open T (and so also S), and then 'listen' for S to close, at which point it closes T as well.
You need to use a Job Object. See Working example of CreateJobObject/SetInformationJobObject pinvoke in .net? and Kill child process when parent process is killed
Do not try 'monitoring for one process', that leaves zombies when the monitoring crashes.
I'm running a process that will take, optimistically, several hours, and in the worst case, probably a couple of days.
I've tried a couple of times to run it and it just never seems to complete (I should add, I didn't write the program, it's just a big dataset). I know my syntax for the command is correct as I use it all the time for smaller data and it works properly (I'll spare you the details as it is obscure for SO and I don't think that relevant to the question).
Consequently, I'd like to leave the program unattended running as a fork with &.
Now, I'm not totally sure whether the process is just grinding to a halt or is running but taking much longer than expected.
Is there any way to check the progress of the process other than ps and top + 1 (to check CPU use).
My only other thought was to get the process to output a logfile and periodically check to see if the logfile has grown in size/content.
As a sidebar, is it necessary to also use nohup with a forked command?
I would use screen for this purpose. see the man for more reference
Brief summary how to use:
screen -S some_session_name - starts a new screen session named session_name
Ctrl + a + d - detach session
screen -r some_session_name returns you to your session
I want to check/improve some correction algorithm I use.
The whole thing is implemented in Matlab and goes something like this
for ii = 1:nn
... % Prepare some input files
parfor i = 1:n
system('...'); % simulation code
end
... % Use the output and prepare some stuff that can be used to prep the next iteration
end
Wherey n is a bigger number than the #Treads I can use. This normaly takes a while to run and in the meantime I would like to use the computer for other (non cpu hungry) tasks. Therefore I would like to run the system calls with low priority.
I already tried to do this using new or start but then the call doesn't wait till it's finished and just proceeds. There would be a dirty hack over checking if the output files exist, but then again I was asking myself if there was not a better solution for that...
Any help would be greatly appreciated
yours
magu_
try using the /wait flag in start command:
>> system( 'start /LOW /WAIT matlab.exe' );
started a new matlab instance and resumed execution only after I closed the opened application.
Of course, you need to replace matlab.exe in my proposed solution with the simulation program name you want to run.
A colleague has a MATLAB startup.m file that contains interactive code (it calls the command questdlg to ask him which project directory he wishes to work in).
This works fine for him when running MATLAB directly. However, he also needs to run MATLAB code in parallel, having started up a matlabpool.
When starting up, the workers in the matlabpool are running his startup.m file, getting to the questdlg and then hanging (infinitely, or until Ctrl C).
An easy solution is to just get rid of the interactive code from his startup.m, as it's not really essential.
But is there a way to detect whether this startup.m is being run by a worker starting up - something similar to isdeployed or ismcc? Then he could keep the interactive code that he finds useful, but only execute it when not starting up a worker.
The command getCurrentWorker seemed like it might be what was needed, but I believe that only works during the execution of a task, rather than at startup.
You could use the usejava function to see if the interactive desktop is running, which is probably a good enough approximation unless you frequently use -nodesktop mode.
if usejava('desktop')
questdlg(...);
end
Take a look at labindex and, failing that, labSend and labReceive.
At least for my R2014b,
isempty(getCurrentWorker)
seem to do the job:
>> getCurrentWorker
ans =
[]
>> parfor i=1:2;disp(getCurrentWorker);end
Worker
Host: IMP.OIMRDS
ComputerType: WIN64
ProcessId: 15784
Worker
Host: IMP.OIMRDS
ComputerType: WIN64
ProcessId: 17220