[Numpy-tickets] [NumPy] #518: a.var(), a.std(), and a.mean() return incorrect type when no axis specified

NumPy numpy-tickets@scipy....
Sat May 12 12:54:20 CDT 2007


#518: a.var(), a.std(), and a.mean() return incorrect type when no axis specified
---------------------+------------------------------------------------------
 Reporter:  charris  |       Owner:  somebody                
     Type:  defect   |      Status:  new                     
 Priority:  normal   |   Milestone:  1.0.3 Release           
Component:  Other    |     Version:  none                    
 Severity:  normal   |    Keywords:  return type var std mean
---------------------+------------------------------------------------------
 The dtype keyword has no effect when the {variance,std,mean} is computed
 using the default axis:

 {{{
 In [28]: eye(2).var(dtype=float32).dtype
 Out[28]: dtype('float64')
 }}}

 It does work when the axis is specified.

 {{{
 In [29]: eye(2).var(axis=0,dtype=float32).dtype
 Out[29]: dtype('float32')
 }}}

 Integer types are always ignored:

 {{{
 In [35]: eye(2).var(axis=0,dtype=int).dtype
 Out[35]: dtype('float64')
 }}}

 The question here is whether int specifies the accumulator type, which
 should probably raise an error, or the return type for values computed
 using float64.

-- 
Ticket URL: <http://projects.scipy.org/scipy/numpy/ticket/518>
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