Can't export my plot to any format

I have a 3d scatter plot I've generated and using either saveas() or export_figure found on the file exchange simply doesn't work. I get the same symptoms if I use .bmp or .png

I receive no error message, and Matlab seems to just enter an endless loop as it says Busy in the bottom left of the window.

Is there some limit to how many points I can plot and still be able to save/export the figure?

My current plot has somewhere around 150,000 triplets....

   A = csvread('ALL_MARKS.csv');               %Open CSV with position and area data
  A = A(:,1:4);
  x = A(:,1);
  y = A(:,2);
  z = A(:,3);
  zavg = mean(z);
  zstdev = std(z);
  SIZE = zeros(length(z),1);
  for i = 1:length(z);
      SIZE(i)=(z(i)-zavg)/zstdev;
  end
  SIZE = abs(SIZE);
  cmap = z;
  figure('color','white');
  %colormap(jet(256));
  set(gcf, 'Position', get(0,'Screensize')); % Maximize figure
  scatter3(x,y,z, SIZE, cmap, 'fill');

currentDirectory = pwd
[upperPath, deepestFolder, ~] = fileparts(currentDirectory)

Tfontargs = {'FontName','Arial','FontSize',12,'FontWeight','bold'};
Lfontargs = {'FontName','Arial','FontSize',12};
title(deepestFolder,Tfontargs{:});
xlabel('X-Position [mm]',Lfontargs{:});
ylabel('Y-Position [mm]',Lfontargs{:});
%zlabel('Area [mm^2]');
axis equal;                                 %Square and set axes to tested area
axis([-2500 2500 -400 12000 0 10000]);
view(90,90);                                %Change plot view to 'overhead view'

load('BWMap','mycmap')                      %Load and set a custom colormap
set(gcf,'Colormap',mycmap)

hcb = colorbar('Location','SouthOutside');
set(hcb,'XTickMode','manual');
xlabel(hcb,'Area [mm²]',Lfontargs{:});
saveas(gcf, 'test.png')

Answer 1

[Walter Roberson]

It looks plausible to me that the saveas() might be the first point in your code that forces the points to be rendered. If so then it might not be the save but rather the rendering. You could find out by tossing in a drawnow() before the saveas, and display a message after that: if the message does not appear then the rendering is the problem.

150,000 triplets is a lot. That is roughly the equivalent to painting every pixel in a 387 x 387 square. On a 1280 x 1024 screen, about one pixel in 8 would be filled if each marker was only 1 pixel (but by default markers are about 18 pixels). It sounds unlikely that the plot would be readable.

Have you considered reducing the density, or rendering the coordinates yourself into an array and then drawing the array? I notice that you set the marker size according to a deviation, but you also set the color according to deviation, so possibly you could combine the two, such as by using color-coded fixed-size markers? The marker to plot would be the one corresponding to the highest z at the pixel.

[Kai]

Thanks for your insight. I see what you are getting at vis a vis being too much data, but the plot does appear onscreen when I call the scatter3 command. It's not smooth and it takes a moment to render, but the plot looks alright and I'd like to export it. I would have expected that actually rendering the plot would be the hard part, not simply saving it as an image file...

Thanks again

[Walter Roberson]

Perhaps if you used getframe() and saved that? With saveas() you are probably getting higher resolution