Bugs item #1745178, was opened at 2007-06-29 07:14 Message generated for change (Comment added) made by gbrandl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1745178&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Library Group: Python 2.4 >Status: Closed >Resolution: Invalid Priority: 5 Private: No Submitted By: Nikke Knatterton (funke_) Assigned to: Nobody/Anonymous (nobody) Summary: pdtri gives wrong results Initial Comment: pdtri function, aka inverse of Poisson cumulative distribution gives wrong results when I use it. For example when expected count is 20: >>> pdtri(20,0.001) 38.041881353850023 when in Matlab: >> poissinv(0.999, 20) ans = 35 I checked the value from http://stattrek.com/Tables/Poisson.aspx where cumulative probability for 35 is 0.999196 and for 38 it is 0.999891...clearly the latter is wrong. Or don't I use the function correctly? (For some reason the probability 0.999 is given as 0.001 in python) ---------------------------------------------------------------------- >Comment By: Georg Brandl (gbrandl) Date: 2007-06-29 07:33 Message: Logged In: YES user_id=849994 Originator: NO There is no "pdtri" function in the Python core and standard library. If this function is coming from SciPy, you should report or discuss that issue with them. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1745178&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
