Drawing a circle with statements

Hello everybody:

I think what I want to do is quite easy, but I could not find in internet how to do it. I want to draw a circle by using the statement if:

If x < R
x=1; 
end

Later, I want to change x=1 to x equal to the value of a function. Can someone help me? Thank you!

Answer 1

[mabel]

Finally I got my own answer.

a=ones(500,500);                   %matrix size
I= 0.5                             %Intesity inside the cirlce
for i=1:500
   for j=1:500
      if ((j-x)^2+(i-y)^2)<=R^2    %condition to make the cirlce
         a(i,j)=I;
      end
   end
end
imshow(a)

Answer 2

[Image Analyst]

It's in the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_create_a_circle.3F

[mabel]

No, it's not at this web. They have another ways to make a circle, but not the one I am asking. I am looking for a matrix with 0, 1, and the 1 make a cirlce.

[Image Analyst]

mabel, it is at that web site -- it was the first example in the FAQ. What you posted as the "Answer" is essentially a for-loop, non-vectorized way of doing the first example in the FAQ. Sorry you didn't recognize that.