B(1,1,1) = 0; B(1, 2, 1) = 1; B(2, 1, 1) = 1; B(2, 2, 1) = 2; B(1,1,2) = 0; B(1, 2, 2) = 1; B(2, 1, 2) = 1; B(2, 2, 2) = 2; X1 = 1.1; X2 = 1.2; X3 = 1.3; A1 = MyInterp3(B, X1, X2, X3); A2 = interpn(B, X1, X2, X3); Err = A1 - A2