Matlab locks up when saving figure with color map using scatter()

I have a Matlab program that generates 3 figures: 2 use the plot() function and the 3rd uses the scatter() function which color maps the points based on a 3rd dimension. The plot() types all display fine and the first 2 I save as jpeg files using print() with no issues; however, when I try to save the 3rd colormapped plot to jpeg using print(), the process is extremely slow (an hour vs. seconds for the normal plots) and I have to use windows task manager to close it if I don't want to wait. If I go to the File menu in the figure itself and try to save as jpeg it does the same thing. I attached the .fig file to this post (below). Using saveas() causes the same issue. The second to last line, "print('-djpeg', file_jpg, '-r300')", is where it bogs down. Is there an alternative method to print() or saveas() that might be faster?

I'm using Matlab R2014a with Windows 7.

      figure
      subplot(2,1,1);
      plot(sec_from_start, WVSS2F_VMR, sec_from_start, WVSS2R_VMR,'-g', sec_from_start,   VMR_C_U,'cx',sec_from_start, VMR_CR2,'-k', sec_from_start, wmr_GE_s,'-y');
      hold on; %holds plot and axis properties
      plot( sec_from_start, PALT_RVS,'.r')
      title(file,'Interpreter','none')
      TAS_thresh=100; %start plot when TAS exceeds a threshold (m/s)
      for i = 1:length(PALT_RVS)
          if TAS(i) > TAS_thresh
              time_plot_start = sec_from_start(i); %start time for plots
              break
          end
      end
      axis([time_plot_start, max(sec_from_start), 0, 14000])
      l=legend(firsty,secondy,thirdy,forthy,fifthy,sixy); set(l,'Interpreter','none')
      xlabel('time (sec from start)')
      ylabel('PPMv, Palt (m)')
      grid
      WVSS_ERR = WVSS2F_VMR - wmr_GE_s; %WVSS2 minus GE chilled mirror

      subplot(2,1,2)
      [AX, H1, H2] = plotyy(sec_from_start, WVSS2F_VMR, sec_from_start, WVSS_ERR);
      %set(H2, 'Marker','.');
      set(H2, 'Color','r');
      set(get(AX(1),'Ylabel'),'String','PPMv'); %set left Y-axis
      set(get(AX(2),'Ylabel'),'String','PPMv error'); %set right Y-axis
      set(AX(1),'xlim',[time_plot_start, max(sec_from_start)]);
      set(AX(2),'xlim',[time_plot_start, max(sec_from_start)]);
      set(AX(2),'ylim',[-2000 2000]);
      set(AX(2),'YTick',[-2000 -1000 0 1000 2000]);
      xlabel('time (sec from start)')
      %title(file,'Interpreter','none')
      l=legend(firsty, 'error (WVSS2F-GE chilled mir.)'); set(l,'Interpreter','none')
      grid
      file_jpg = [path_file, '_out.jpg'];
      print('-djpeg', file_jpg, '-r300'); %save figure to file with resolution rXXX
      figure
      [H] = plot(wmr_GE_s, WVSS2F_VMR);
      set(H, 'Color','b'); set(H, 'marker', '.'); set(H, 'line', 'none')
      ylabel('WVSS2 (PPMv)'); %set left Y-axis
      xlabel('GE chilled mirror (PPMv)')
      axis([0, 40000, 0, 40000])
      title(file,'Interpreter','none')
      l=legend('WVSS2F vs. GE chilled mir.'); set(l,'Interpreter','none')
      set(gca,'xTick',0:5000:40000)
      set(gca,'yTick',0:5000:40000)
      grid
      file_jpg = [path_file, '_scatter_out.jpg'];
      print('-djpeg', file_jpg, '-r300'); %save figure to file with resolution rXXX
      hold on;
      figure

      %%plot with colormap
      colormap(jet); %defines bype of color map for points in scatter plot
      cmin = 0; cmax = 200; V=[cmin, cmax];
      scatter1 = scatter(wmr_GE_s,WVSS2F_VMR,10,TAS_RVSM);
      caxis(V); %set color map range
      hcb = colorbar('YTick', [cmin 0 cmax],'YTickLabel', {num2str(cmin),'   Palt=0 m', num2str(cmax)}); %add colorbar scale to plot
      ylabel('WVSS2 (PPMv)'); %set left Y-axis
      xlabel('GE chilled mirror (PPMv)')
      axis([0, 40000, 0, 40000])
      set(gca,'xTick',0:5000:40000)
      set(gca,'yTick',0:5000:40000)
      title('test','Interpreter','none')
      grid
      file_jpg = [path_file, '_scatter_color_out.jpg'];
      print('-djpeg', file_jpg, '-r300'); %save figure to file with resolution rXXX
      %saveas(gcf, file_jpg); %save figure to file with resolution rXXX

[Maryam Abdolahpour]

I have exactly the same issue in my Matlab 2017 and Matlab 2022

Answer 1

[Abhinaya Kennedy]

Problems with saving the scatter plot as a JPEG file is likely due to the complexity of the plot, especially with the colormap and the potentially large number of data points. You could try

• Breaking plots into smaller sections and saving those separately, then combining them if needed might help.
• Reducing the resolution of the saved image. Instead of -r300, you could try -r150 or -r100 to see if this speeds up the process.
• Using a different file format that might handle complex plots better, such as PNG or TIFF. You can do this by changing '-djpeg' to '-dpng' or '-dtiff' in the print function.
• Reducing the number of data points in your scatter plot or simplifying the colormap to see if that has any effect.
• Updating to a more recent version of MATLAB, as newer versions often have performance improvements and bug fixes. If you have access to a newer version of MATLAB, consider using the exportgraphics function, which can handle complex graphics more efficiently.

% Assuming the figure is already created
file_jpg = [path_file, '_scatter_color_out.png'];  % Change to PNG
print('-dpng', file_jpg, '-r150');  % Save with lower resolution