var paper = Raphael("huh",500,500);

​

    paper.customAttributes.pathXY = function( x,y ) {

      var pathArray = Raphael.parsePathString(this.attr('path'));

      var transformArray = ['T', x - this.pathXY('x'), y - this.pathXY('y') ];

        return { 

          path: Raphael.transformPath( pathArray, transformArray) 

        };

    };

    Raphael.el.pathXY = function(xy) {

        if(this.constructor.prototype == Raphael.st){ // if a set

          var positions = [];

          this.forEach( function( element ){

            var position = ( element.pathXY(xy) ); // recursive for sets of sets

            if(position){ // if set, calculate and return average X or Y of set

              positions.push(position);

            }

          });

          return eval(positions.join('+')) / positions.length;

        } else { // if an element

          if(xy == 'x' || xy == 'y'){ // to get x or y of path

            xy = (xy == 'x') ? 1 : 2;

            var pathPos = Raphael.parsePathString(this.attr('path'))[0][xy];

//            console.log(pathPos);

            return pathPos;

          } else { // to initialise a path's pathXY, for animation

            console.log('init',this.pathXY('x'),this.pathXY('y'), this);

            this.attr({pathXY: [this.pathXY('x'),this.pathXY('y')]});

          }

       }   

    }

    Raphael.st.pathXY = Raphael.el.pathXY;

​

​

var path = paper.path('M100 100,105 105,95 105,95 95,105 95,100 100');

​

var path2 = paper.path('m50 50,105 105,-95 -105,95 95,-105 -95,100 100');

var path3 = paper.path('m0 50,105 5,-95 -5,95 95,-5 -5,0 0');

​

var set = paper.set(path2, path3);

var set2 = paper.set(path);

set2.push(set);

​

​

set2.pathXY(); // necessary to avoid pathXY animation hitting NaN

// get path position when you need X or Y to stay the same

set2.animate({pathXY: [150,set2.pathXY('y')]},1000, '<', function(){

  set2.animate({pathXY: [set2.pathXY('x'),150]},1000, 'elastic', function(){

    set2.animate({pathXY: [50,50]}, 1000, 'bounce');

  });

});