[Numpy-tickets] [NumPy] #559: var() on a size=1 array should raise exception.

NumPy numpy-tickets@scipy....
Tue Jul 31 01:56:01 CDT 2007


#559: var() on a size=1 array should raise exception.
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 Reporter:  gpk     |        Owner:  somebody
     Type:  defect  |       Status:  new     
 Priority:  normal  |    Milestone:          
Component:  Other   |      Version:  none    
 Severity:  normal  |   Resolution:          
 Keywords:          |  
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Comment (by cdavid):

 Well, if you want to be picky, var is not the variance, but the estimated
 variance. In numpy, var and std are biased, so at least their formula
 makes sense.

 I tried on matlab, octave and R: the first two give back 0, the latter
 gives back NA, which is not that surprising giving the focus of each. It
 all depends on which context var and std are used in: maybe they are not
 used in a statistical context ? I would say that the current behaviour for
 a general purpose scientific environment makes sense.

-- 
Ticket URL: <http://projects.scipy.org/scipy/numpy/ticket/559#comment:1>
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