plot the region represented by 'ABS (x) + abs (y)≤1'

I know the picture of this inequality, but he has x and y as variables. How do I plot it

Answer 1

[Chunru]

If you don't want to derive the boundary of the surface, you can do the following:

[xx, yy] = meshgrid(linspace(-2, 2), linspace(-2,2));
zz = ones(size(xx));
zz( (abs(xx) + abs(yy)) > 1) = nan;
surf(xx, yy, zz, 'EdgeColor', 'none'); view(0, 90); axis equal

[军 川]

Thank you.I've been experimenting with a two-dimensional approach, and I didn't realize that the three-dimensional representation worked so well.