Colorbar doesn't show colours the right way round?

Hello Community,

I have been bar plotting some data, and have graduated the colours relative to their values in the data which works fine. The issue I am having is that when I call the colorbar - the colours dont match the plotted colour scheme of the data. Following an answer from Image Analyst, I write the graduated bar plot like this:

numberofbars = length(var1);
barColorMap = colormap(summer);
x = 1 : numberofbars;

for b = 1 : numberofbars
  % Plot one single bar as a separate bar series.
  handleToThisBarSeries(b) = bar(x(b), var1(b));
  % Apply the color to this bar series.
  set(handleToThisBarSeries(b), 'FaceColor', barColorMap(b,:));
  hold on;
end

colorbar

and get this as the output:

which for the bar plot is what I want, but the colorbar colours are inverted to the data. I have tried this to invert the colorbar scheme (following Walter Roberson advice):

    oldcmap = colorbar;
    colorbar( flipud(oldcmap) );

but unfortunately this doens't sort the colorbar issue in my case.

Does anyone have any advice on how to resolve this please?

Many thanks,

10B.

[10B]

Ah - of course I have also noticed that the colorbar index is not to the correct scale.

Again, any pointers welcome!

Answer 1

[J Philps]

Walter was on the right track with his suggestion, but I believe you want to flip the colormap of the colorbar. Here is code demonstrating how you can flip the colormap of the colorbar graphical object:

figure

surf(peaks)

c1 = colorbar;

figure

surf(peaks)

c2 = colorbar;

cmap = colormap;

upside_down_cmap = flipud(cmap);

colormap(c2, upside_down_cmap);

Answer 2

[Image Analyst]

The problem is your chosen color, barColorMap(b,:), should not use b, the loop index, as an index. It should use an index that is chosen according to the height of the bar.