a disc in a matrix

I need a disc inside a matrix. for example:

thanks for your help:)

Answer 1

[Walter Roberson]

http://matlabwiki.mathworks.com/MATLAB_FAQ

[Amy]

sorry.where can i find the sol? ><

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_do_I_create_a_circle.3F

Answer 2

[Roger Stafford]

It would be better to use the term 'disk' or 'disc' for this. The term 'circle' generally refers to the one-dimensional curve surrounding a two-dimensional disk.

Let ic and jc be the desired indices for the disk's center and r be its radius, and let m and n be the numbers of rows and columns, respectively, in the array.

 [I,J] = ndgrid(1:m,1:n);
 M = double((I-ic).^2+(J-jc).^2<=r^2); % <-- M should be your desired array