I think that this results must be the same: In [3]: math.atan2(-0.0,-1) Out[3]: -3.1415926535897931
In [4]: math.atan2(-0,-1) Out[4]: 3.1415926535897931 In [5]: -0 == -0.0 Out[5]: True This is python 2.4.4c0 on Debian GNU/Linux. Regards, Vedran Furač -- http://mail.python.org/mailman/listinfo/python-list