code: function(axis){
      var _self = this,
        type = axis.type,
        C,
        name;
      if(!type && axis.categories){
        type = 'category';
      }
      if(type == 'category' || type == 'timeCategory'){
        if(!axis.categories){
          axis.autoTicks = true; //标记是自动计算的坐标轴
        }
      }else if(!axis.ticks && type != 'circle'){
        axis.autoTicks = true; //标记是自动计算的坐标轴
      }
  
      axis.plotRange = _self.get('plotRange');
      axis.autoPaint = false;  //暂时不绘制坐标轴，需要自动生成坐标轴
  
      type = type || 'number';
      name = Util.ucfirst(type);
      C = Axis[name];
      if(C){
        return  _self.get('parent').addGroup(C,axis);
      }
      return null;
    }
docs: 创建坐标轴