def write_bin(filename, **kwargs):
    """Write the raw point data in `PyntCloud.xyz` to a binary file.

    Parameters
    ----------
    filename: str
        The created file will be named with this
    kwargs: numpy.ndarray.tofile supported kwargs
        Check NumPy documentation on raw binary files for all possibilities.

    Returns
    -------
    boolean
        True if no problems
    """
    # Extract just the x, y, z coordinates from the points dataframe
    point_array = kwargs['points'][['x', 'y', 'z']].values

    # Remove the points from kwargs now.
    # Any remaining kwargs are meant for np.ndarray.tofile()
    del kwargs['points']

    # Test that any remaining kwargs are only those allowed
    # It should be the empty set
    remaining_kwargs = set(kwargs.keys()) - set(['sep', 'format'])
    if not len(remaining_kwargs) == 0:
        raise ValueError(('Only keyword arguments meant for numpy.ndarray.tofile '
                          'are accepted. Please see the numpy documentation'))

    point_array.tofile(filename, **kwargs)

    return True