如何获取brush框选的数据echarts 柱状配置项内容和展示

在图上款选一批数据后，如何获取这些数据

      app.title = '世界人口总量 - 条形图';

option = {
    title: {
        text: '世界人口总量',
        subtext: '数据来自网络'
    },
    tooltip: {
        trigger: 'axis',
        axisPointer: {
            type: 'shadow'
        }
    },
    legend: {
        data: ['2011年', '2012年']
    },
    brush: {
        toolbox: ['rect', 'polygon', 'lineX', 'lineY', 'keep', 'clear'],
        xAxisIndex: 0
    },
    grid: {
        left: '3%',
        right: '4%',
        bottom: '3%',
        containLabel: true
    },
    yAxis: {
        type: 'value',
        boundaryGap: [0, 0.01]
    },
    xAxis: {
        type: 'category',
        data: ['巴西','印尼','美国','印度','中国','世界人口(万)']
    },
    series: [
        {
            name: '2011年',
            type: 'bar',
            data: [18203, 23489, 29034, 104970, 131744, 630230]
        },
        {
            name: '2012年',
            type: 'bar',
            data: [19325, 23438, 31000, 121594, 134141, 681807]
        }
    ]
};




myChart.on('brushSelected', renderBrushed);

function renderBrushed(params) {
    var brushed = [];
    var brushComponent = params.batch[0];

    for (var sIdx = 0; sIdx < brushComponent.selected.length; sIdx++) {
        var rawIndices = brushComponent.selected[sIdx].dataIndex;
        brushed.push('[Series ' + sIdx + '] ' + rawIndices.join(', '));
    }

    myChart.setOption({
        title: {
            backgroundColor: '#333',
            text: 'SELECTED DATA INDICES: \n' + brushed.join('\n'),
            bottom: 0,
            right: 0,
            width: 100,
            textStyle: {
                fontSize: 12,
                color: '#fff'
            }
        }
    });
}