How do i create a colormap that seperates ranges between exact values?

I'm trying to create a colormap for a plot that contains 3 colors. Values equal or under a specific value (say 0.73) should be orange, and values over a specific value (say 1.2) should be blue. All values between should be white. The top and bottom thresholds (0.73, 1.2, For example) are determined at run time. Anyone knows how to do it? Thanks.

[Adam]

If it is that simple a scenario you'd be better off creating a true RGB image by explicitly mapping your data to colours. A colourmap is a discretised set of colourbins, usually 256 or 512 of them and your data gets mapped implicitly onto that. If you have floating point data then you cannot provide a colourmap with an explicit colour change at an arbitrarily defined value because of the descretisation.

Answer 1

[Sudharsana Iyengar]

Try something like this, custom colormap with 5 colors.

mymap = [0 0 0 1 0 0 0 1 0 0 0 1 1 1 1];

surf(peaks) %This is default peaks program in MATLAB. you can use it for ur code also. colormap(mymap)