[Scipy-tickets] [SciPy] #1811: lognorm has parameters in the wrong order compared to norm

SciPy Trac scipy-tickets@scipy....
Fri Jan 11 15:01:23 CST 2013


#1811: lognorm has parameters in the wrong order compared to norm
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 Reporter:  rdw      |       Owner:  somebody   
     Type:  defect   |      Status:  new        
 Priority:  normal   |   Milestone:  Unscheduled
Component:  Other    |     Version:  0.11.0     
 Keywords:  lognorm  |  
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Comment(by josefpktd):

 The distributions in scipy.stats are very consistent (sometimes too much).

 loc and scale of lognorm refers to the lognormal distribution, not to the
 underlying normal distribution.
 While, it looks like, R has mu and sd of the underlying normal
 distribution.

 Because of the transformation, the parameters of the lognormal
 distribution are also transformed versions of the underlying normal
 distribution.
 But scipy.stats.lognormal is treated as it's own distribution and doesn't
 know directly about the underlying normal distribution.
 (That's were the consistent and generic implementation restricts us.)

-- 
Ticket URL: <http://projects.scipy.org/scipy/ticket/1811#comment:4>
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