echarts自定义柱形图缩放时超出坐标轴范围

[小猴子emo]

经过测试只要是自定义的柱形图，在用了dataZoom后，缩放会导致柱子的下方以及上方超过原来坐标轴的正常范围，非自定义的确正常，请大家帮忙

var data = [[10, 16, 3, 'A'], [16, 18, 15, 'B'], [18, 26, 12, 'C'], [26, 32, 22, 'D'], [32, 56, 7, 'E'], [56, 62, 17, 'F']];
var colorList = ['#4f81bd', '#c0504d', '#9bbb59', '#604a7b', '#948a54', '#e46c0b'];

data = echarts.util.map(data, function (item, index) {
    return {
        value: item,
        itemStyle: {
            normal: {
                color: colorList[index]
            }
        }
    };
});

function renderItem(params, api) {
    var yValue = api.value(2);
    var start = api.coord([api.value(0), yValue]);
    var size = api.size([api.value(1) - api.value(0), yValue]);
    var style = api.style();

    return {
        type: 'rect',
        shape: {
            x: start[0],
            y: start[1],
            width: size[0],
            height: size[1]
        },
        style: style
    };
}

option = {
    title: {
        text: 'Profit',
        left: 'center'
    },
    tooltip: {
    },
    dataZoom: [
        {
            type: 'slider',
            yAxisIndex: 0,
            filterMode: 'filter',
            startValue:4,
            endValue:40
        }
    ],
    xAxis: {
        scale: true
    },
    yAxis: {
    },
    series: [{
        type: 'custom',
        renderItem: renderItem,
        label: {
            normal: {
                show: true,
                position: 'top'
            }
        },
        dimensions: ['from', 'to', 'profit'],
        encode: {
            x: [0, 1],
            y: 2,
            tooltip: [0, 1, 2],
            itemName: 3
        },
        data: data
    }]
};

[囧]

function renderItem(params, api) {
    
    var yValue = api.value(2);
    var start = api.coord([api.value(0), yValue]);
    var size = api.size([api.value(1) - api.value(0), yValue]);
    var style = api.style();
    var zero = api.coord([0, 0]);
    var height = api.getHeight() - params.coordSys.y;

    return {
        type: 'rect',
        shape: {
            x: start[0],
            y: start[1],
            width: size[0],
            height: size[1] - (zero[1] - height)
        },
        style: style
    };
}