How to set Assumptions for function handle?

easy case:

I'v gut a function handle:

f = @(x,y,z)x.^2+y.^2+z.^2-1;

fimplicit3(f)

for plotting an implicit function. Now I also want to assume z > 0

What's the deal?

Answer 1

[Stephan]

See fimplicit3 example here and use interval argument:

f = @(x,y,z)x.^2+y.^2+z.^2-1;
fimplicit3(f, [-1, 1, -1, 1, 0, 1])