echarts3的雷达图，tooltip的触发方式设定为axis时无效。:配置报错 

我在图说中做了一个雷达图，在轴线上提示效果不错，可是同样的代码拿到echarts3官网的demo页面，却出不来提示。请问@Kener-林峰  ，想在雷达图的轴线上触发提示，仅在tooltip中写trigger:'axis'不行吗？

图说中的代码：

{ title: { x: "left", y: "top" }, tooltip: { trigger: "axis" }, legend: { orient: "vertical", x: "right", y: "bottom", data: ["人流量占比(%)", "等候超时人数占比(%)"] }, toolbox: { show: false, feature: { mark: { show: true }, dataView: { show: true, readOnly: false }, restore: { show: true }, saveAsImage: { show: true } } }, polar: [ { indicator: [ { text: "河南", min: 0, max: 12 }, { text: "陕西", min: 0, max: 12 }, { text: "山西", min: 0, max: 12 }, { text: "河北", min: 0, max: 12 }, { text: "山东", min: 0, max: 12 }, { text: "安徽", min: 0, max: 12 }, { text: "湖北", min: 0, max: 12 }, { text: "湖南", min: 0, max: 12 }, { text: "四川", min: 0, max: 12 }             ], type: "polygon", axisLabel: { show: false } } ], calculable: true, series: [ { name: "", type: "radar", data: [ { value: [10.9, 8, 8, 8, 7, 9, 10, 11, 10], name: "人流量占比(%)" } ], symbolSize: 2 }, { name: "", type: "radar", data: [ { value: [5.8, 7.8, 12.9, 8, 8.2, 7.2, 9, 8, 9], name: "等候超时人数占比(%)" } ], symbolSize: 2 } ], animation: true, animationEasing: "ExponentialOut" }