Get a plot to automatically load different colors using a matrix

I am trying to plot 16 different sets of data onto 1 plot, and my adviser suggested concatenating the data I am using (amplitude data) and then when plotting it should load all 16 in different colors automatically. I was able to concatenate the data, but for some reason I can't get it to plot correctly. Here is a snippet of my data below:

    load(FILENAME);
  
  respidx = find(n1p2amp > THR_CRIT); 
  allamp = cat(2, n1p2amp,allamp);

        plot (masker*ELEC_SPACE,allamp)%plots amplitude data
        xlabel('Masker Electrode (re: electrode spacing)')
        ylabel ('Amplitude (mV)');

        text(masker(respidx(maxidx))*ELEC_SPACE,n1p2amp(respidx(maxidx)),[num2str(maskch)],...
            'VerticalAlignment','middle',...
            'HorizontalAlignment','right',...
            'FontSize',10)
        hold on;
        set(gca,'XLim',[0*ELEC_SPACE 16*ELEC_SPACE],'YLim',[-0.1 0.6]);
        set(gca, 'XTick',0:4*ELEC_SPACE:16*ELEC_SPACE);

This is all contained within the loop "i" which is essentially numbered 1:16. I have a 16x16 matrix for each subject, so the x-axis has 16 points with each point containing 16 data points, if that makes sense. I just don't want to have to manually tell this to do 16 different colors. Thanks!

Answer 1

[Mike Garrity]

I think your advisor is just referring to the fact that if you give plot a YData array which is an MxN array, then it will plot them as M curves and give each one its own color.

Consider this example:

d = gallery('moler',16,.5); % an interesting 16x16 matrix

Executing this:

plot(1:16,d);

creates the same thing as:

hold on
for i=1:16
  plot(1:16,d(i,:));
end

and it also gives each of the curves a different color.

BTW, you can also get the second example to generate different colors by using "hold all" instead of "hold on".

Also, the plot command pulls its colors from the ColorOrder property of the axes rather than the colormap. The colormap is only used by objects which have CData, such as surface or image.

[Lindsay]

Mike, thank you so much. I will try this later today and let you know how it went. I'm still relatively new to Matlab so your instructional response helps a great deal!

Answer 2

[Image Analyst]

The easiest way is to specify the color when you plot. If you don't you get the default colors. Maybe you'd be interested in my ColorOrder demo where you can alter the default colors.

[Lindsay]

Thanks! I was able to get mine to work by using 'hold all.' I would love to have more color options but this looks a little behind my current skill set with Matlab. Is there an easy way to implement this?

[Lindsay]

Oooo I figured it out. THANK YOU!

[Image Analyst]

You're welcome. Maybe you could "Vote" for the answer even if it didn't earn your "Acceptance", if it at least you learned something from it.