Is there a way to build a defined set of colors which the gscatter command to accept?

Earlier this year I built a MATLAB script which produces group scatter plots for up to 8 data sets. This is a sample of that code;

      % Setup the group scatter plot
      figure('Name','Measured Values');
      colors = 'rgbcmykw'; % MATLAB’s default predefined color spec
      h = gscatter(T_Time, Rad_Val, Leg_Nom, colors, 'o',  15, 'on');
      for n = 1:length(h)
          set(h(n), 'MarkerFaceColor', colors(n));
      end
      set(gca,'YScale','log');
      % Change the semilog labels to decimal units
      New_YTickLabel = get(gca,'Ytick');
      set(gca,'YTickLabel',New_YTickLabel);

This code works well for the most part. The drawback being an 8th data set plotted in white (where I manually change the color from white to grey).

But now I’ve been asked to modify this code to account for up to 12 data sets. Knowing that there are only 8 pre-defined colors, I suspected MATLAB would throw an error since the number of data sets exceeds the number of available colors. And it did. The exact error reads as follows:

Index exceeds matrix dimensions

It points to this line of code: set(h(n), 'MarkerFaceColor', colors(n));

Since there are only 8 pre-defined, hard coded colors in MATLAB, I’m looking for a method/technique to build a pallet of 12 colors. These 12 colors would be used by the gscatter command and in the for loop.

Can this be done?

Answer 1

[Walter Roberson]

Instead of using a color name letter, use an RGB vector.

colors = [1 0 0; 0 1 0; 0 0 1; 0 1 1; 1 1 0; 1 0 1; 0 0 0; 1 1 1 ...]  %recheck the values

set(h(n), 'MarkerFaceColor, colors(n,:))

[Brad]

Walter, thank you. This works just fine!!

[Image Analyst]

You can use a whole bunch of pre-named colormaps if you want, for example, make colormap with 100 colors:

colors = jet(100); % Or can use hot, winter, cool, autumn, etc.....