A = [ 0 0.5; 0.5 1]; x = [0 1]; y = [0 1]'; x2 = [0 0.5 1]; y2 = [0 0.5 1]'; A2 = interpn(x,y,A,x2,y2); isequal(A2, [ 0 0.25 0.5; 0.25 0.5 0.75; 0.5 0.75 1])