How to plot a special plane x-y=5 with surf function

Hi there! I am trying to plot special planes such as "x-y=5" and "z=2x" in which one dimension is missing using surf function. I am really confused here. Does anyone have a clue? Many thanks!

Answer 1

[Chunru]

x = (-10:10)';
y = x - 5;
z = [-10 10]';
nz = length(z);

xx = x*ones(1, nz);
yy = y*ones(1, nz);
zz = ones(length(x), 1) * z';

surf(xx, yy, zz)

Answer 2

[Sam Chak]

HI @Wei Wei, not exactly sure about the "special" thing. Do you expect something like this?

[X, Y] = meshgrid(-1:2/40:1, -5:5/40:0);
Z1 = X - Y - 5;
surf(X, Y, Z1), hold on
Z2 = 2*X;
surf(X, Y, Z2)
xlabel('x'), ylabel('y'), zlabel('z')