[Scipy-tickets] [SciPy] #299: gammaincinv gives incorrect answers

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Tue Oct 31 17:40:43 CST 2006


#299: gammaincinv gives incorrect answers
---------------------------+------------------------------------------------
 Reporter:  djcmackay      |       Owner:  somebody
     Type:  defect         |      Status:  new     
 Priority:  normal         |   Milestone:          
Component:  scipy.special  |     Version:          
 Severity:  normal         |    Keywords:  gammainc
---------------------------+------------------------------------------------
 For extreme values, gamaincinv gives the answer '0.0'
 when it should not do so.
 Examples:

 >>> import scipy.special as S
 >>> S.gammainc( 50 , 12.00 )
 2.3998794536786009e-16
 >>> S.gammaincinv( 50 , 2.39e-16 )
 11.996909478523992
 >>> S.gammainc( 50 , 11.00 )
 8.2075477738848345e-18
 >>> S.gammaincinv( 50 , 8e-18 )
 0.0


 Python 2.4.3 (#2, Oct  6 2006, 07:52:30)
 [GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2

 David
 mackay at mrao.cam.ac.uk

-- 
Ticket URL: <http://projects.scipy.org/scipy/scipy/ticket/299>
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