'Convert from Point object in EPSG:900913 to a Coordinate object'

def projCoordinate(self, point):

    diameter = ((2 * _pi) * 6378137)
    zoom = (_log(diameter) / _log(2))
    coord = Coordinate(point.y, point.x, zoom)
    coord.column = (coord.column + (diameter / 2))
    coord.row = ((diameter / 2) - coord.row)
    return coord
