Creating a heat map that would color different sectors of a circle

Hi all,

I have plotted 197 circles each with 3 sectors on a single plot. I have a value (a number between 1 and 30) associated with each sector and would like to create a heat type map that would color each sector of a circle based on its associated value. The values are stored in 3x197 matrix.

Any help is much appreciated.

Answer 1

[Image Analyst]

Are these circles on an image? You forgot to show your plot/image so we have to just guess. Anyway, assuming the circle values are in an image with values rounded to the nearest integer (1 to 30), you can just apply a colormap to the figure

colorMap = jet(30);  % Create a colormap with 30 different colors.
% colorMap is just a numerical array at this point, 
% it's not been sent to the display adapter yet.  We'll do that next.
colormap(colorMap);  % Apply the colorMap to our figure.

[Amir A]

Hi,

I'm sorry, this is my first post so i am still kinda new to the whole thing. I have attached my plot which includes 197 circles, each with 3 sectors. Once the color map is set, how do i plot each sector individually to get the heat map?

Thank you very much.

[Image Analyst]

OK. It would have been helpful if you'd thought to post that image in your original post. I think you'll have to follow the approach suggested by Thorsten. I was going to suggest the same thing now after I see your image above.

Answer 2

[Thorsten]

You can define a colormap with 30 entries with, e.g.,

cmap = jet(30);

and then draw a filled circle segment with code from http://www.mathworks.com/matlabcentral/answers/6322-drawing-a-segment-of-a-circle and color the segment by using the number as index to your colormap. You have to do this for all three segments for all your 197 circles.

[Amir A]

Thank you