I have three matrices. First one is values of temperatures in (x,y) points, and second and third matrix is x and y coordinates, respectively. Rectangular block with temperatures is on figure(1) and it looks appropriately, but when I tried to neglect the values x>2 and y<2, to get L-shaped diagram, it doesn't look fine. Is there any solution to this problem? I submit the picture how the figure(2) should look.