Circle of zeros within a circle of ones in a matrix

I'm trying to add a filled circle of zeros within an already existing circle of ones in a matrix of zeros.

My current code for the circle of ones in a matrix of zeros:

[x,y] = meshgrid(1:500,1:500);

cir = sqrt((x-250.5).^2+(y-250.5).^2)<=250;

Answer 1

[Image Analyst]

Code samples are in the FAQ. You will be able to easily modify them.

https://matlab.fandom.com/wiki/FAQ#How_do_I_create_a_circle.3F