@ Override public int compare ( IAtomContainer a , IAtomContainer b ) { Point2d p1 = center ( a ) ; Point2d p2 = center ( b ) ; if ( p1 . x > p2 . x ) return + 1 ; if ( p1 . x < p2 . x ) return - 1 ; if ( p1 . y > p2 . y ) return + 1 ; if ( p1 . y < p2 . y ) return - 1 ; return 0 ; }
Compare two AtomContainers based on their 2D position .