defining limit for a colorbar after calculating the limit from a given data

I have a voltage data V in a matrix. From this data I am calculating some other data Z. I am plotting Z with pcolor. Now my professor said that I cannot use the absolute vale of V, instead find out the mean of the min and max and then use those limits for finding Z so that eventually Z limits also get affected by this action. I am clueless, somebody please help me is understanding this and finding out mean of V, and the appropriate limits!

Answer 1

[Fangjun Jiang]

mean()
max()
min()
caxis()
set(gca, 'CLim', [cLow, cHigh]);