code: function at(o, pos) {
    // number recalculation (don't bother converting to SVG.Number for performance reasons)
    return typeof o.from == 'number' ?
      o.from + (o.to - o.from) * pos :
  
    // instance recalculation
    o instanceof SVG.Color || o instanceof SVG.Number || o instanceof SVG.Matrix ? o.at(pos) :
  
    // for all other values wait until pos has reached 1 to return the final value
    pos < 1 ? o.from : o.to
  }
docs: Calculate position according to from and to