如何在tooltip formatter函数中获取timeline currentIndex?echarts 柱状配置项内容和展示

刚刚学习echarts，想tooltip中显示非data中的数据。请参见代码 tooltip: { formatter: function(params) { var res = params.dataIndex + ":" + timeline.currentIndex + ":" + params.seriesIndex; return res; } 总是显示最大值3

      var timeLineData = [2016, 2017, 2018]
var yData = ['变压器', '断路器', '电流互感器', '电压互感器', '避雷器', '隔离开关'];
var WLData = ['一级预警', '二级预警', '三级预警'];
TipData = [
    ['2016-5-6 → 2016-5-6', '2016-5-6 → 2016-4-6', 3, 1, 1, 2],
    ['2017-5-6 → 2017-5-6', '2017-5-6 → 2017-4-6', 3, 1, 1, 2]
];
WOData = {
    2016: [6, 1, 1, 1, 2, 1],
    2017: [1, 3, 5, 1, 2, 2],
    2018: [1, 1, 0, 4, 1, 4]
}
WSData = {
    2016: [2, 1, 1, 1, 2, 1],
    2017: [1, 4, 1, 3, 1, 0.1],
    2018: [1, 1, 0, 4, 1, 4]
}
WTData = {
    2016: [1, 3, 3, 1, 1, 2],
    2017: [1, 1, 0, 4, 1, 4],
    2018: [1, 1, 0, 4, 1, 4]
}
tooltipOption = {
    trigger: 'axis',
    padding: 10,
    axisPointer: { // 坐标轴指示器,坐标轴触发有效
        type: 'shadow' // 默认为直线,可选为:'line' | 'shadow'
    }

};
option = {
    baseOption: {
        title: {},
        timeline: {
            show: true,
            axisType: 'category',
            autoPlay: true,
            playInterval: 3000,
            top: 20,
            controlStyle: {
                itemSize: 16,
            },
            data: [],

        },
        tooltip: {},
        legend: {
            data: []
        },
        grid: {
            left: '2%',
            right: '2%',
            bottom: '3%',
            containLabel: true
        },
        xAxis: {
            boundaryGap: false,
            type: 'value',
            data: ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12'],
            interval: 1,
            min: 0,
            max: 12,
        },
        yAxis: [{
            type: 'category',
            data: yData
        }],
        dataZoom: [{
            type: 'slider',
            showDataShadow: false,
            showDetail: false,
            show: true,
            yAxisIndex: 0,
            left: '98%',
            right: 0,
            //bottom: 45,
            start: 1,
            end: 20
        }],
        series: [],
        animationEasing: 'liner',
        animationDelayUpdate: function(idx) {
            return idx * 3
        }
    },

    options: []
};
for (var n = 0; n < timeLineData.length; n++) {
    ij = parseInt(n);
    option.baseOption.legend.data = WLData;
    option.baseOption.timeline.data.push(timeLineData[n]);
    option.options.push({
        title: {
            show: true,
            'text': timeLineData[n]
        },
        series: [{
            name: WLData[0],
            type: 'bar',
            stack: '总量',
            barWidth: 15,
            data: WOData[timeLineData[n]],
            tooltip: {
                formatter: function(params) {
                    var res = '<span style="display:inline-block;margin-right:5px;border-radius:10px;width:9px;height:9px;background-color:' + params.color + '"></span>';
                    res += params.dataIndex + ":" + timeline.currentIndex + ":" + params.seriesIndex;
                    return res;

                }
            }
        }, {
            name: WLData[1],
            type: 'bar',
            stack: '总量',
            label: {
                normal: {
                    show: true
                }
            },
            data: WSData[timeLineData[n]],
            tooltip: {
                formatter: function(params) {
                    var res = '<span style="display:inline-block;margin-right:5px;border-radius:10px;width:9px;height:9px;background-color:' + params.color + '"></span>';
                    res += params.dataIndex + ":" + timeline.data[0] + ":" + params.seriesIndex;
                    return res;
                }
            }
        }, {
            name: WLData[2],
            type: 'bar',
            stack: '总量',
            label: {
                normal: {
                    show: true
                }
            },
            data: WTData[timeLineData[n]],
        }]
    });
}