Calculating circle´s points coordinates.

[Andrew Henshaw]

"Joshua Muskovitz" <josh at open.com> wrote in message
news:3a0b07f3_3 at corp.newsfeeds.com...
> If you are working in degrees, create a list of angles with "range(0,360)"
> or something like that.  Then, you can use map to substitute the
> corresponding x,y coordinates for the angle.
>
...snip...

I'm not sure of the original poster's requirements, but if he wants to plot
a set of points on a integer-based grid (e.g., a memory-mapped display),
then the Bresenham Circle algorithm is usually recommended.  It's very fast
and it doesn't have a problem with "holes" in the point set.

Here's a pythonized implementation.

##########################
#
#  Bresenham Circle Algorithm
#
##########################

def circle(radius):
    x = 0
    y = radius
    switch = 3 - (2 * radius)
    points = []
    while x <= y:
        points.extend([(x,y),(x,-y),(-x,y),(-x,-y),\
                       (y,x),(y,-x),(-y,x),(-y,-x)])
        if switch < 0:
            switch = switch + (4 * x) + 6
        else:
            switch = switch + (4 * (x - y)) + 10
            y = y - 1
        x = x + 1
    return points


Good luck!

Andy Henshaw