To check, you effectively have
F = @(w) R(w) .* exp(i * theta(w));
where R and theta are functions?
w = linspace(-pi, pi, 101);
result = F(w);
After that you need to decide how you want to represent the complex plane. There is no inherent ability to plot in the complex plane as humans cannot see into the complex plane. But you can do things like,
plot(w(:), [real(w(:)), imag(w(:))])
