Return the minimum of an array, ignoring any NaNs.

        :param a: The array.
        :return: The minimum value of the array.

def fn_min(self, a, axis=None):
        """
        Return the minimum of an array, ignoring any NaNs.

        :param a: The array.
        :return: The minimum value of the array.
        """

        return numpy.nanmin(self._to_ndarray(a), axis=axis)