[PYTHON MATRIX-SIG] Handling null data points

[Duncan Child]

Thanks for the suggestions. I am not sure that my previous post made it 
clear that I was talking about null data values in the Numerical Extension
Python array. I have to use the Numeric arrays because I have so much 
data to work with. Still, if there is a more general solution that can also 
be applied outside the Numeric Extension that would be even better.

> The notion of a "missing value" is very important for data analysis.
> I implemented such a type at USGS for use in database interfaces.
> Unfortunately, this was never released and I haven't gotten around
> to reimplementing it, although the implementation was close to
> trivial. I think this would be very valuable.  If people are 
> interested, I'd be willing to release an implementation.

Yes please.

> I think it would also be valuable to consider supporting some 
> special floating-point value (e.g. NAN) for use in floating-point
> arrays.  This special value would be converted to/from the special
> "missing value" object when accssed in Python.

NaN sounds interesting - at the moment I just use 1e20. This works fine
for me as I only have to handle vectors of floats but it would be nice
to have a solution that would be applicable to other data types. 


Thanks

Duncan

 

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