m = 1e3;
bs = ‘\b’;
sp = ‘ ‘;
msg = ‘%d iterations…\n’; % carriage return included in case error interrupts loop
msglen = length(msg)-3; % compensate for conversion character and carriage return
fprintf(1,sp(ones(1,ceil(log10(m+1))+msglen)));
for i=1:m
fprintf(1,[bs(mod(0:2*(ceil(log10(i+1))+msglen)-1,2)+1) msg],i);
pause(0.01);
end

This can be modified a bit if you don’t want the progress digit at the beginning:

m = 1e3;
bs = ‘\b’;
sp = ‘ ‘;
msg = ‘Iteration %d…\n’; % carriage return included in case error interrupts loop
msglen = length(msg)-3; % compensate for conversion character and carriage return
fprintf(1,sp(ones(1,msglen)));
for i=1:m
fprintf(1,[bs(mod(0:2*(ceil(log10(i))+msglen)-1,2)+1) msg],i);
pause(0.01);
end

Note that it’s a good idea to include a carriage return at the end of your message because any error message from a loop whose progress you’re monitoring doesn’t start with a new line.

Also, maybe it’s obvious, but as long as the code whose progress you’re monitoring takes a nominal amount of time to execute, don’t forget to remove any pause() statements from your loop. All they do is slow it down and I haven’t seen any problems with the command window not updating. …Except… I have however seen what looks like a race condition when the schemes above are called in a sufficiently tight loop and the first character or two don’t get written (R2011b, Mac OS X 10.6.8). It’s most noticeable when the loop increment is a power of ten. The non-updating of those characters in the command window persists even after the code has finished executing.

Can you please tell us exactly what version of MATLAB you are running on PC and linux? Thanks.

–Loren

http://blogs.mathworks.com/loren/2007/08/01/monitoring-progress-of-a-calculation/#comment-16357

to the following:

tic;
for i = 1:1000000;
   if (mod(i,1000) == 0);
      disp(i/1000000)
   end
end
toc

and I found the latter 10x faster than the fastest waitbar.

Gianluca- I don’t know. But I think you need to start WITH the desktop instead of -nodesktop. That’s just a guess based on the warnings. Otherwise, I suggest you contact technical support (link on right of the blog).

–Loren

    progress.text = sprintf( 'Completed: %%3.0f%%%%%%s' );
    progress.clear = sprintf( '%s', ...
        sprintf('\b')*ones(1,length(sprintf(progress.text,0,''))) );
    N = 100+400*rand();
    for n = 0:N
        fprintf( progress.text, n/N*100, progress.clear );
        pause( 0.01 );
    end
    fprintf( progress.text, n/N*100, sprintf('\n') );

Do you know what the reason is?
Cheers
Gianluca

You CAN but it’s not necessarily a good idea. A better idea is to write myfprintf and call that. Put your extra code in there and then call myfprintf. Otherwise, the version of fprintf will have your modifications even for applications that aren’t expecting it – perhaps code from other people that you have downloaded, etc.

To change fprintf, you need to find a directory on your path in which to create a subdirectory called @char NOT on your path. Inside that @char directory, create the version of fprintf that you want, and then, use the builtin function to call the version of fprintf from MATLAB from your own. Again, I REALLY DISCOURAGE you for doing this! The different name scenario is much safer.

–Loren

Good suggestion. Please use the support link at the right to make the request (it counts more if it comes from you than if it comes from me).

–Loren