Ben Bush wrote: > is there any code to decide whether a point is located within the circle > by three other points?
# Converted from my C++ code. # C.f. http://www.ics.uci.edu/~eppstein/junkyard/circumcenter.html def circumcenter(x0, y0, x1, y1, x2, y2): x0m2 = x0 - x2 y1m2 = y1 - y2 x1m2 = x1 - x2 y0m2 = y0 - y2 x0p2 = x0 + x2 y1p2 = y1 + y2 x1p2 = x1 + x2 y0p2 = y0 + y2 D = x0m2*y1m2 - x1m2*y0m2 # You probably want to test for D being close to 0 here centerx = (((x0m2*x0p2 + y0m2*y0p2)/2*y1m2) - (x1m2*x1p2 + y1m2*y1p2)/2*y0m2) / D centery = (((x1m2*x1p2 + y1m2*y1p2)/2*x0m2) - (x0m2*x0p2 + y0m2*y0p2)/2*x1m2) / D return centerx, centery def incircle(x0, y0, x1, y1, x2, y2, x, y): centerx, centery = circumcenter(x0, y0, x1, y1, x2, y2) return ((x-centerx)**2 + (y-centery)**2 <= (x0-centerx)**2 + (y0-centery)**2) -- Robert Kern [EMAIL PROTECTED] "In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter -- http://mail.python.org/mailman/listinfo/python-list
