docs: function (val) {
          var axis = this.getAxis();
          var rect = this.getRect();
          var pt = [];
          var idx = axis.orient === 'horizontal' ? 0 : 1;
  
          if (val instanceof Array) {
              val = val[0];
          }
  
          pt[idx] = axis.toGlobalCoord(axis.dataToCoord(+val));
          pt[1 - idx] = idx === 0 ? (rect.y + rect.height / 2) : (rect.x + rect.width / 2);
          return pt;
      }