MATLAB: Contourf: fill inside instead of outside

Question

Hi, how can I fill the area within the circle? At the moment Matlab fills the area outside. I would like the outside to be white and the inside to be filled. Thanks.

relamdt=-4:0.1:4;
imlamdt=-4:0.1:4;
[x,y]=meshgrid(relamdt,imlamdt);
axis square;
lamdt=x+i*y;
sig = (1 + lamdt);
v = [1,1];
contourf(x,y,abs(sig),v)

Answer 1

contourf(x, y, -abs(sig), -v)

Alternately, possibly

[~,h] = contourf(x, y, abs(sig), v);
drawnow();     %seems to be needed to get NodeChildren created
bg = h.NodeChildren(2).ColorData;
h.NodeChildren(2).ColorData = uint8([255; 255; 255; 255]);
ax = ancestor(h,'axes');
ax.Color = bg;