circle

function out = circle(Im,value,center_x,center_y,r)     #Image to insert a circle, the color value of the circle, the x coordinate of the circle center, the y coordinate of the circle center, the radius of the circle
  out = [];
  if value != 0 && value != 1
    return
  endif
  for i = 1:rows(Im)
    for j = 1:columns(Im)
      Im(i,j) = ifelse(sqrt((j-center_x)^2 + (i-center_y)^2) <= r,value,Im(i,j));
    endfor
  endfor
  out = Im;
endfunction