How to create a quadrant-circle shape-matrix?

Currently I have a problem with creating a matrix with a quadrant-shape. The problem is as follow:

I would like to have a 138 x 140 matrix with values of 2 and 3. Inside and on the quadrant circle, the values should be 2. Everything outside the circle, I need to have a value of 3. The radius of the circle is 138 (=R138).

I was thinking of using 'triu' (and then flip) in matlab: then I will not get a circle, but a triangle instead (have not tried it yet). And that is not what I want.

What is the simplest way to create this matrix?

Answer 1

[Image Analyst]

See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_create_an_arc.3F.

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