[Numpy-discussion] setting decimal accuracy in array operations (scikits.timeseries)

Marco Tuckner marcotuckner@public-files...
Wed Mar 3 16:23:59 CST 2010


Thanks to all who answered.
This is really helpful!

>> If you are still seeing actual calculation differences, we will
>> need to see a complete, self-contained example that demonstrates
>> the difference.
> 
> To add a bit more detail -- unless you are explicitly specifying
> single precision floats (dtype=float32), then both numpy and excel
> are using doubles -- so that's not the source of the differences.
> Even if you are using single precision in numpy, It's pretty rare for
> that to make a significant difference. Something else is going on.
> 
> I suspect a different algorithm, you can tell timeseries.convert how
> you want it to interpolate -- who knows what excel is doing.
I checked the values row by row comparing Excel against the Python results.

The the values of both programs match perfectly at the data points where
no periodic sequence occurs:
so those values where the aggregated value results in a straight value
(e.g. 12.04) the results were the same.
At values points where the result was a periodic sequence (e.g.
12.222222 ...) the described difference could be observed.

I will try to create a self contained example tomorrow.

Thanks a lot and kind regards,
Marco



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