interpolate_na documentation

[bertcoerver]

What is your issue?

According to the documentation for xarray.Dataset.interpolate_na, additional keywords are passed on to numpy.interp when method="linear". In one of the examples one such additional keyword is fill_value (="extrapolate").

But according the the linked documentation for numpy.interp, that function only takes left, right and period as keyword arguments.

The given example does work though... Does it really use numpy.interp or does it perhaps use scipy.interpolate.interp1d, which does have a keyword called fill_value?

[husainridwan]

From what I was able to gather, numpy.interp only takes three keyword arguments as **kwargs i.e. left, right, and period but not fill_value. So when passing fill_value as a keyword argument to xarray.Dataset.interpolate_na with method="linear", it does not use numpy.interp but it uses scipy.interpolate.interp1d(), which provides the fill_value parameter.

[husainridwan]

I'll like to update this in the documentation @TomNicholas

[TomNicholas]

@alrho007 great! We would welcome a pull request to update this :)