def point2str ( pnt ):
    """ point2str( pnt )

    format a 3d data point (list of 3 floating values) for output to a .scad file.

    Also used to do equality comparison between data points.

    @param pnt - list containing the x,y,z data point coordinates
    @returns '[{x}, {y}, {z}]' with coordinate values formatted by specifications
    """
    # IDEA use command line parameter to set the precission
    # IDEA have call time precission, so internal use (for point comparison) can be higher
    return ''.join ([ '[', ', '.join ([ '%.9g' % c for c in pnt ]), ']' ])