MATLAB: Looping a function m-file, figures not closing

figure closing

Hi,

I'm running a script which repeatedly calls a function I wrote (using a for loop). In this function there is a command to plot some data, save it to a .jpg, save the workspace to a .mat, then close the figure.

If I run the function on its own it does all this perfectly, but when I run the script, the function plots the image, saves it, but doesn't close it. The figure hangs there until it's time to plot it again in the next iteration.

I can't work out why MATLAB is not processing this command.

side question: is there a way to plot an image, save it, but not actually have it pop up? This code takes hours to run and it keeps minimising my screen when I'm watching the TV!

Thanks,

Mike

Best Answer

I assume a DRAWNOW after closing the figure might solve the problem.

Opening new figures needs a lot of time. It is much faster to open one figure only and update the axes only, or even better the drawn object:

tic;
for i = 1:100
  FigH = figure;
  plot(1:10, rand(1, 10));
  drawnow;
  delete(FigH);
end
toc;
% >> Elapsed time is 15.660328 seconds.
tic;
FigH = figure;
LineH = plot(1:10, rand(1, 10));
for i = 1:100
  set(LineH, 'YData', rand(1, 10));
  drawnow;
end
toc;
% >> Elapsed time is 0.914224 seconds.

Related Solutions

MATLAB: Is there a way to save snapshots of figures in a LiveScript without keeping the figure objectss open in a for loop

use saveas() to save the figure image.

test1.mlx, file size is 753k. 20 figures are saved. Each contains individual figure objectives.

for k=1:20
    h=figure;
    plot(rand(3));
end

test2.mlx, file size is 666k. 20 figures are saved but each is an image.

for k=1:20
    h=figure;
    plot(rand(3));
    saveas(h,'test.png');
    imshow('test.png');
end

When your data is really large and complex, maybe the .mlx file with image could be much smaller.

MATLAB: M-file function

Your function is calling itself without approaching any convergance or something that will allow it to end. Therefore it will run forever and eventually out of memory (hence the error). Try splitting it up into a script and a function as so:

Script:

 %creating window of plot from -5 to 50 using stepsize 0.25 for t x-axis
 %t should be on the x axis, v should be on the y axis
 k=0; 
for i= -5:.25:50
    k = k+1;
    t(k)=i;
    v(k)=vPieceWise(t(k));
end 
plot(t,v);
 
figure
plot(t,v);
hold on

Function:

%Part A: Mfile function to compute v as a function of t
function v = vPieceWise(t)
 if (t < 0)
        v = 0;
    elseif (0 <= t)&&(8<=16)
        v = -5*t+10*t.^2;
    elseif (8<=16)&&(t<=16)
        v = 624 - 3*t;
    elseif (t<=16)&&(t<=26)
        v = 12*(t-16).^2+36*t;
    elseif (26<t)
        v = 2136*exp(-0.1*(t-26));
 end

Best Answer

Related Solutions

MATLAB: Is there a way to save snapshots of figures in a LiveScript without keeping the figure objectss open in a for loop

MATLAB: M-file function

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