pcolor question

Hi, I have two variables that both depend on a third. Something like, x1=z1, x2=z2, x3=z3 and y1=z2, y2=z3, y3=z1.

I would like to plot them to see the relationship between the two, I think pcolor will do what I want but am having some difficulties using it. My understanding is that I first create a grid using the x and y values, [X,Y]=meshgrid(x,y) but I am not sure how to generate an array using z to fit to this grid, i.e. so I can do pcolor(X,Y,Z). Anyone able to help??