Efficiency Map plotting

I am trying to plot the efficiency map using a contour function for the torque speed curve shown below. the problem is, the contour function, plots for the whole surface of the matrix. But i only want the contour plot to be under the torque speed curve so that the part above the torque speed curve is white.

the link below is a link of the torque speed curve. any help would be much appreciated

http://imageshack.us/photo/my-images/826/torquespeedcurve.png/

[Junfei Tang]

You can have a look at the link below. I think this might be similar to your question. http://www.mathworks.com/matlabcentral/answers/44515#answer_208604

Answer 1

[Ragavendra]

Any answers for efficiency map plotting?

[Junfei Tang]

You can have a look at the link below. I think this might be similar to your question. http://www.mathworks.com/matlabcentral/answers/44515#answer_208604