saveas won't save my figure when in a for cycle

Dear Matlab comunity,

I run into a problem with a command saveas. I have a for loop in which I create a set of surf plots, which I would like to save independently and for each cycle. When I run just the part with the surf plots, it saves just as intended. But when I run the whole for loop, it does not. Any suggestions?

The surf plot is a part of a one big for loop, so I post just the code that applies to surf plots. In this part 3 different surf plots are ought to be plotted and there is one more just like these 3 couple dozens lines earlier.

%% Plotting error surface plot  
% In this section the distance between the points is plotted

figure('units','normalized','outerposition',[0 0 1 1]);
surfPlot = surf(X_grid,Y_grid,delta_x,'FaceAlpha',0.9);
    colorbar
    zlim([4.5 5.5])
title('Vzdialenosti medzi bodmi v x smere')
    xlabel('Šírka snímky')
    ylabel('Výška snímky')
    zlabel('\Delta x medzi bodmi')
surfPlot.EdgeColor = 'none';

outputBaseFileName = sprintf('Frame %d.jpg',i);
  outputSaveFile_sumX = fullfile('C:\Users\Adam\Documents\Škola\Uniza\Diplomová práca\8. Finálne meranie auta\Zabery\calibration images 50mm\Kalibracia 50mm side to side\Results\delta_x',outputBaseFileName);
  saveas(gcf,outputSaveFile_sumX)
  close all

figure('units','normalized','outerposition',[0 0 1 1]);
surfPlot = surf(X_grid,Y_grid,delta_y,'FaceAlpha',0.9);
    colorbar
    zlim([4.5 5.5])
title('Vzdialenosti medzi bodmi v y smere')
    xlabel('Šírka snímky')
    ylabel('Výška snímky')
    zlabel('\Delta y medzi bodmi')
surfPlot.EdgeColor = 'none';

outputBaseFileName = sprintf('Frame %d.jpg',i);
  outputSaveFile_sumY = fullfile('C:\Users\Adam\Documents\Škola\Uniza\Diplomová práca\8. Finálne meranie auta\Zabery\calibration images 50mm\Kalibracia 50mm side to side\Results\delta_y',outputBaseFileName);
  saveas(gcf,outputSaveFile_sumY)
  close all
  
figure('units','normalized','outerposition',[0 0 1 1]);
surfPlot = surf(X_grid,Y_grid,delta_sum,'FaceAlpha',0.9);
    colorbar
    zlim([6.5 7.5])
title('Absolutne vzdialenosti medzi bodmi')
    xlabel('Šírka snímky')
    ylabel('Výška snímky')
    zlabel('\Delta sum medzi bodmi')
surfPlot.EdgeColor = 'none';

outputBaseFileName = sprintf('Frame %d.jpg',i);
  outputSaveFile_sum = fullfile('C:\Users\Adam\Documents\Škola\Uniza\Diplomová práca\8. Finálne meranie auta\Zabery\calibration images 50mm\Kalibracia 50mm side to side\Results\delta_sum',outputBaseFileName);
  saveas(gcf,outputSaveFile_sum)
  close all

[Cris LaPierre]

What does it or does it not do when this is placed inside a for loop?

Ignoring the saving part for a minute, does your code even create the figures you want to save when inside a for loop?

[Adam Rajcan]

Yes, everything works fine except for saving. When in a loop, the whole calculation works well, I get all the plots, each of them closes before the next one appears and it goes like this for the whole cycle. Everything seems to work fine, except the saving part.

[Image Analyst]

Give us the whole for loop. You probably have the for loop setup so that the iteration counter has no loops, maybe something like

for k = 1 : 0

or something that evaluates to 0.

[Adam Rajcan]

Edit: It actually works for the first plot, but not for the later 3, which are shown. For these it saves only the first frame, but instead of i (which is the for cycle count) it saves under number 56 and then it does not do anything.

Here is the code for the first one that actually works.

figure('units','normalized','outerposition',[0 0 1 1]);
surfPlot = surf(X_grid,Y_grid,Z_grid,'FaceAlpha',0.9);
    colorbar
title('Ochýlka rozložená na plochu obrazu')
    xlabel('Šírka snímky')
    ylabel('Výška snímky')
    zlabel('Projekčná odchýlka')
surfPlot.EdgeColor = 'none';

outputBaseFileName = sprintf('Frame %d.jpg',i);
  outputSaveFile_Error = fullfile('C:\Users\Adam\Documents\Škola\Uniza\Diplomová práca\8. Finálne meranie auta\Zabery\calibration images 50mm\Kalibracia 50mm side to side\Results\error',outputBaseFileName);
  saveas(gcf,outputSaveFile_Error)
  close all

[Adam Rajcan]

Just as I was about to post the whole for loop I spotted that I have another for loop in the middle of it using the same iteration counter i=1:56, which resulted into saving all the later plots under frame number 56 instead of using the correct iteration count. That was the reason.

Sorry for posting such a mistaken script, but thank you for your help. Now it works fine.

for i=1:boardSize(1,2)-1-StepSize           % Coloumns
    for k=1:boardSize(1,1)-1-StepSize       % Rows        
            delta_x(k,i) = X_me(k,i+StepSize) - X_me(k,i);              % Distance between the points along the x axis
            delta_y(k,i) = Y_me(k+StepSize,i) - Y_me(k,i);              % Distance between the points along the x axis
            delta_sum(k,i) = sqrt(delta_x(k,i).^2 + delta_y(k,i).^2);   % Absolute distance between the points
    end
end

Answer 1

[Veronica Taurino]

Something like this within each loop?

FolderName='path to save your figures here'
FigList = findobj('Type', 'figure');
for iFig = 1:length(FigList)             
    FigHandle = FigList(iFig);             
    FigName   = get(FigHandle, 'Name');
    saveas(FigHandle, fullfile(FolderName, [FigName '.jpg']));             
end