I don't understand this: a(a=a(T,b)) I don't know what you're trying to get. Are you trying to get a profile or contours or something like that? For example, let's say that T is a 2D array and for a certain row and column, T will have a value. Do you then want to find all rows and column where T = 42 (for example, or some other value)? Something like this code from the help?