echarts 折线图区域底部是斜的

Question

1.用echarts3 编写折线图，折线下方区域用渐变色覆盖，我想让我的图面积区域的底部是平的，为啥会是斜的呢
2.这是我的代码`series: [

                    {
                        name: '净值',
                        type: 'line',
                        stack: '总量',
                        areaStyle: {
                            normal: {
                                color: {
                                    type: 'linear',
                                    x: 0,
                                    y: 0,
                                    x2: 0,
                                    y2: 1,
                                    colorStops: [{
                                        offset: 0, color: 'rgba(255,216,162,1)'
                                    }, {
                                        offset: 0.5, color: 'rgba(255,216,162,0.5)'
                                    }, {
                                        offset: 1, color: 'rgba(255,216,162,0)'
                                    }],
                                    globalCoord: false // 缺省为 false

                                }

                            }
                        },
                        showSymbol: false,
                        lineStyle: {
                            normal: {
                                width: 0.8
                            }
                        },
                        dimensions: ['date', 'nav', 'sinceyesterday', 'totalnetvalue', 'incomeratio', 'incomeunit'],
                        encode: {
                            x: 'date',
                            y: category,
                        },
                        data: data
                        // data:[['2017/9/21','1.2','1.3'],['2017/9/22','1.4','1.4'],['2017/9/23','1.6','1.4'],['2017/9/24','1.5','1.4'],['2017/9/25','1.4','1.4'],['2017/9/26','1.3','1.4'],['2017/9/27','1.0','1.4']]
                    }`

3.结果是下方图示，

Answer 1

我已经解决了这个问题，

dimensions: ['date', 'nav', 'sinceyesterday', 'totalnetvalue', 'incomeratio', 'incomeunit'],
encode: {
    x: 0,
    y: 1,
},

这样就解决了，等我再好好研究研究，给一个比较好的回答