echarts3的雷达图，tooltip的触发方式设定为axis时无效：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"
}