pdora...@pas-de-pub-merci.mac.com (Pierre-Alain Dorange) writes: > Ben Bacarisse <ben.use...@bsb.me.uk> wrote: > >> >>> math.atan2(INF, INF) >> 0.7853981633974483 >> >> I would have expected NaN since atan2(INF, INF) could be thought of as >> the limit of atan2(x, y) which could be any value in the range. And I'd >> have guessed atan2(0, 0) would have been NaN too but > > i'm not a math expert, but the limit of atan2 would be 45°, so pi/4 > radians (0,7854). > As x,y are coordinates, the both infinite would tend toward 45°.
The limit of atan2(x, x) is as you describe, but there is no reason to pick that one case. lim{x->oo,y->oo}atan2(x, y) is undefined unless a relationship is given between x and y and you get get any result you like in the range of atan2 by choosing one or other relationship. -- Ben. -- https://mail.python.org/mailman/listinfo/python-list