code: function size(path,mod,rad,ang) {
      if (!mod) var mod = 0
      if (typeof rad != "number") var rad = undefined
      if (typeof ang != "number") var ang = undefined
      path.attrTween("d", function(d){
        if (rad == undefined) var r = d.d3plus.r ? d.d3plus.r : d3.max([d.d3plus.width,d.d3plus.height])
        else var r = rad
        if (ang == undefined) var a = d.d3plus.segments[d.d3plus.shape]
        else var a = ang
        if (!vars.arcs[d.d3plus.shape][d.d3plus.id]) {
          vars.arcs[d.d3plus.shape][d.d3plus.id] = {"r": 0}
          vars.arcs[d.d3plus.shape][d.d3plus.id].a = Math.PI * 2
        }
        var radius = d3.interpolate(vars.arcs[d.d3plus.shape][d.d3plus.id].r,r+mod),
            angle = d3.interpolate(vars.arcs[d.d3plus.shape][d.d3plus.id].a,a)
        return function(t) {
          vars.arcs[d.d3plus.shape][d.d3plus.id].r = radius(t)
          vars.arcs[d.d3plus.shape][d.d3plus.id].a = angle(t)
          return arc(d)
        }
      })
    }
docs: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is the main "arcTween" function where all of the animation happens for each arc. ----------------------------------------------------------------------------