Incorrect error message in tools.tool?

[jbrockmendel]

https://github.com/statsmodels/statsmodels/blob/master/statsmodels/tools/tools.py#L205

    # handle ndarrays and catch array-like for an error
    elif data.__class__ is np.ndarray or not isinstance(data, np.ndarray):
        if not isinstance(data, np.ndarray):
            raise NotImplementedError("Array-like objects are not supported")

The message that Array-like objects are not supported doesn't make sense to me. It looks like it should be the exact opposite: only array-like objects are supported. Am I missing something?

For that matter, is there a reason why the first condition is specifically ndarray without allowing subclasses (i.e. change data.__class__ is np.ndarray to isinstance(data, np.ndarray))?

[josef-pkt]

I'm not sure. Most likely I never looked at it.

masked arrays and matrices are array_likes that we don't support.