On Fri, Jul 30, 2010 at 6:15 PM, Christopher Barker <chris.bar...@noaa.gov> wrote: > Guillaume Chérel wrote: >> As for the details about my problem, I'm trying to compute the total >> surface of overlapping disks. I approximate the surface with a grid and >> count how many points of the grid fall into at least one disk. > > That is a highly approximate way to do it - which may be fine, but I > doubt any floating point errors you get are going to make it worse. >
It is a problem in my algorithm because it modifies the number of points that are considered inside a given disk (namely, the points that are at the very boundary of the disk), and results in something like an "index out of bounds" error later. > > if you >> know of another good way to compute the surface of overlapping disks, >> I'd be glad to know. > > Are these "disks" exactly round? If so -- use coordinate geometry to > calculate it exactly (or as exactly as floating point allows ;-) ) > > I just googled: "area of intersecting circles" > > And got a bunch of hits. Originally, I was looking to solve my problem quickly, and a rough approximation was (and is) enough. There are indeed solutions for computing the area of 2 intersecting disks, but my problem may involve many more than 2 disks at a time, which makes things a lot more complicated (to me, at least). _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
