Fixed a bug in ompy.library.log_interp1d

[vetlewi]

I've fixed a minor bug in ompy.library.log_interp1d which prevented the user to set the kind keyword arguments to scipy.interpolate.interp1d. The default value is now set to kind='linear' and can be changed by the user.

I'm also considering adding a lin_interp1d to ompy.library. Mainly since it could complement the log_interp1d.

def lin_interp1d(xx, yy, **kwargs):
    """ Interpolate a 1-D function.logarithmically """
    kwargs.setdefault('kind', 'linear')
    lin_interp = interp1d(xx, yy, **kwargs)
    return lin_interp

Any objections?

One could also redo the two interpolation functions into a single function interp1d(xx, yy, type='log/lin', **kwargs) but that would require a little work to properly propagate the change to the entire package, and would not be backwards compatible if any users have used it explicitly. One could preserve the current function as a "legacy" solution with the 'new' as a wrapper:

def interp1d(xx, yy, type='log', **kwargs):
    if type == 'lin':
        return lin_interp1d(xx, yy, **kwargs)
    if type == 'log':
        return log_interp1d(xx, yy, **kwargs)
    else:
        raise TypeError(f"Unsupported 'type' keyword: '{type}'")

and add a depreciation warning when the legacy versions are used.