distributions moment doesn't call argcheck (Trac #934) #1461
Description
Original ticket http://projects.scipy.org/scipy/ticket/934 on 2009-04-28 by @josef-pkt, assigned to @josef-pkt.
again problem with setting parameters, bounds in _argcheck, which is not automatically called.
error only occurs on first use of the distribution, so difficult to test.
example (will also affect other distributions):
>>> print stats.truncnorm.moment(2,-lbdec,lbdec)
Traceback (most recent call last):
File "C:\Josef\eclipsegworkspace\scipybranch2\dist\Programs\Python25\Lib\site-packages\scipy\stats\distributions.py", line 915, in moment
mu, mu2, g1, g2 = self._stats(*args,**mdict)
File "C:\Josef\eclipsegworkspace\scipybranch2\dist\Programs\Python25\Lib\site-packages\scipy\stats\distributions.py", line 3307, in _stats
nA, nB = self.na, self.nb
AttributeError: 'truncnorm_gen' object has no attribute 'na'
if other method is used first, then it works:
>>> stats.truncnorm.cdf(2,-lbdec,lbdec)
1.0
>>> stats.truncnorm.moment(2,-lbdec,lbdec)
0.4377245949036388
self.na and self.nb are assigned in _argcheck
class truncnorm_gen(rv_continuous):
def _argcheck(self, a, b):
self.a = a
self.b = b
self.nb = norm._cdf(b)
self.na = norm._cdf(a)
return (a != b)