def nanargmin(values, axis=None, skipna=True, mask=None):
    """
    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    --------
    result : int
        The index of min value in specified axis or -1 in the NA case

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, 2, 3, np.nan, 4])
    >>> nanops.nanargmin(s)
    0
    """
    values, mask, dtype, _, _ = _get_values(
        values, skipna, fill_value_typ='+inf', mask=mask)
    result = values.argmin(axis)
    result = _maybe_arg_null_out(result, axis, mask, skipna)
    return result