MATLAB: How to remove data on left hand region of the image

Question

[x, y, frequency] = textread('SRAS_opt.txt','%f %f %f');
A2 = reshape(x,[200,200]);
B2 = reshape(y,[200,200]);
Vb = 24*10^-6*frequency;
V2b = reshape(Vb,[200,200]);
imagesc(V2b);

I would like to remove the data on the left hand side region so I get a new velocity image.

Answer 1

Use pcolor. Plot the color bar......See the limits and values.......which ever values you don't want replace them with NaN or remove them.....