柱形图缩放报错echarts 折线配置项内容和展示

代码115行,如果柱形图是颜色渐变,那么缩放功能将会报错

      // Echart - bar & line
var axisY = {
    axisLabel: {
        show: false,
    },
    axisLine: {
        show: false
    },
    axisTick: {
        show: false
    },
    splitArea: {
        show: false
    },
    splitLine: {
        show: false
    }
}
var axisX = {
    axisLine: {
        show: false,
    },
    axisTick: {
        show: false
    },
    splitArea: {
        show: false
    },
    splitLine: {
        show: false
    }
}
var barArr = [201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220];
var lineArr = getRandomm(20, 100);
var barArr_val = getRandomm(20, 10000);
var lineArr_val = getRandomm(20, 1000);

option = {
    title: {},

    xAxis: [{
            type: 'category',
            boundaryGap: true,
            data: barArr
        }
    ],
    dataZoom: [{
        show:false,
        type: 'slider',
        xAxisIndex: 0,
        filterMode: 'empty',
        start: 0,
        end: 20
    }, {
        show:false,
        type: 'inside',
        xAxisIndex: 0,
        filterMode: 'empty',
        start: 20,
        end: 50
    }],
    yAxis: [{
            type: 'value',
            scale: true,
        },
        {
            type: 'value',
            scale: true,
        }
    ],
    series: [{
        name: '折线图',
        type: 'line',
        label: {
            normal: {
                show: true,
                position: [-6, -24],
                textStyle: {
                    color: "#ee5b16", //文字
                    fontSize: 12
                }
            }
        },
        itemStyle: {
            normal: {
                show: true,
                borderWidth: 3,
                color: "#f8be41" // 圆点
            }
        },
        lineStyle: {
            normal: {
                color: "#f7bd42" // 线
            }
        },
        data: barArr_val
    }, {
        name: '柱形图',
        type: 'bar',
        yAxisIndex: 1,
        label: {
            normal: {
                show: true,
                position: [0, -24],
                textStyle: {
                    color: "#0095d1", //文字
                    fontSize: 12
                }
            }
        },
        barCategoryGap:"50%",
        itemStyle: {
            normal: {
                color: '#71d6f5'
                // color: new echarts.graphic.LinearGradient(
                //     0, 0, 0, 1, [
                //         { offset: 0, color: '#71d6f5' },
                //         { offset: 1, color: '#b1f1fc' }
                //     ]
                // )
            }
        },
        data: lineArr_val
    }]
};
// 随机数
function getRandomm(i, max) {
    var arr = [];
    while (i > 0) {
        var num = Math.floor(Math.random() * max + 1);
        arr.push(num);
        i--;
    }
    return arr;
}