fsurf: interval from parameters

hello. when plotting this surface

syms u v
x = u;
y = v;
z = 4 - u^2 - v^2;
%fsurf(x, y, z, [-4 4 -4 4])
fsurf(x, y, z)

I was wondering if there is a way to specify the interval in terms of the u and v parameters?

for example, when u^2 + v^2 must be <= 4, something like

fsurf(x, y, z, [ u^2 + v^2 <= 4])

regards, Danny.

Answer 1

[darova]

If i plot something round i usually use polar coordinates

t = linspace(0,2*pi,30);    % angle array
r = 0:5;                    % radius array
[T,R] = meshgrid(t,r);      % create grid
z = 4 - R.^2;
[x,y] = pol2cart(T,R);      % convert to cartesian
surf(x, y, z)

[Danny Van Elsen]

ok, thank you for this workaround.

but does this mean that the original question is impossible?

something like

fsurf(x, y, z, [ u^2 + v^2 <= 4])

?

[darova]

I think it's impossible