Should numpy.sqrt(-1) return 1j rather than nan?

David Goldsmith David.L.Goldsmith at noaa.gov
Thu Oct 12 11:24:40 CDT 2006


Greg Willden wrote:
> May I suggest the following change to generate_umath.py?
>
> <completely untested string change>
> 'sqrt' :
>     Ufunc(1, 1, None,
>           'square-root elementwise. For real x, the domain is 
> restricted to x>=0.\n\
>           For complex results for x<0 see numpy.scimath.sqrt',
>           TD(inexact, f='sqrt'),
>           TD(M, f='sqrt'),
>           ),
> '
>
> When sqrt throws a ValueError would it be possible/appropriate for the 
> error message to mention numpy.scimath.sqrt?
>
> I'm just trying to think of other ways to help make the transition as 
> smooth as possible for new users.
And helpful error messages are one of Python's best features - in 
general, numpy doesn't have enough of 'em, IMO.

DG
>
> Greg
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