渲染多个图表，独享x轴

[helloyoucan]

• I am using English in this issue. 在这个 Issue 中我使用了英文（强烈建议）。

General Questions

• Required: I have read the document and examples and tried to solve it by myself. （必填）我读过了文档和教程，并且曾试图自己解决问题。
• Required: I have searched for similar issues and that didn't help. （必填）我搜索过 issue 但是没有帮助。
• Required: I have tried with the latest version of ECharts and still have this problem. （必填）我试过最新版本的 ECharts，还是存在这个问题。

In this issue, I have provided information with: 在这个 issue 中我提供了以下信息：

• Required: issue type；（必填）issue 类型
• Required: one sentence description in issue details；（必填）一句话的问题描述
• Required: demo；（必填）能反映问题的例子（如果你想提问或报 bug）
• Required: ECharts version；ECharts 版本

Issue Type

• I have a question to ask about how to use ECharts to ...；我想提问如何使用 ECharts 实现某功能
• I have a bug to report；我想要报 bug
• I have a feature to request, e.g.: I'd like a new feature that ...；我需要一个新功能
• I have a feature to enhance, e.g.: The current feature should be improved in the way that ...；我希望改进某个功能
• There's something wrong with the documents；文档有些问题
• Others, or I'm not sure which issue types to choose here；其他，或我不知道应该选什么类型

Issue Details

Expected Behavior

Current Behavior

Online Example

Topics

• Legend
• Tooltip
• Event
• Performance
• SVG
• Map
• ECharts GL
• Third-party libraries, e.g.: Vue.js, React

Anything Else We Need to Know

Environment

• ECharts version；ECharts 版本: {DESCRIBE_HERE}

• It happens only on certain browsers or operating systems. 对于特定浏览器或操作系统才会出现的问题，请提供相应环境信息：{BROWSER_VERSION_OR_OS_INFORMATION_HERE}

[helloyoucan]

版本：3.x
//option

const xAxisData = [2,4,6,8,10]
const xAxisData2 = [1,2,3,4,5,6,7,8,9,10]
const datas = [4,8,6,2,4]
const datas2 = [1,0,1,0,1,0,1,0,1,0]
function setFontSize(size, width = 1920) {
  return size * (document.body.clientWidth / width)
}
option =((theme)=> {
  const color = {
    white: {
      text: '#333',
      line: '#666'
    },
    dark: {
      text: '#fff',
      line: '#999'
    }
  }[theme]
  return {
    title: {
      text: 'XXX',
      top: setFontSize(30),
      left: setFontSize(45),
      textStyle: {
        fontSize: setFontSize(40),
        fontWeight: 'bolder',
        color: color.text
      }
    },
    grid: {
      left: setFontSize(50),
      right: setFontSize(50),
      bottom: setFontSize(30),
      top: setFontSize(90),
      containLabel: true
    },
    legend: {
      top: setFontSize(100),
      textStyle: {
        color: color.text
      },
      data: ['价格走势（ 元/斤 ）', '销量（ 斤 ）']
    },
    xAxis: [
      {// 价格走势的X轴
        data: xAxisData2,
        position: 'top',
        // show: false,
        // type: 'value',
        // boundaryGap: false,
        axisTick: { show: true, alignWithLabel: true, lineStyle: { width: setFontSize(2), color: '#ffffff' }},
        axisLine: { lineStyle: { color: color.text, width: setFontSize(2) }},
        axisLabel: { fontSize: '.2rem', color: color.text }
      },
        {// 销量(斤)的X轴
        data: xAxisData,
        position: 'bottom',
        // type: 'value',
        // boundaryGap: false,
        // show: false,
        axisTick: { show: false, alignWithLabel: true, lineStyle: { width: setFontSize(2), color: '#ffffff' }},
        axisLine: { lineStyle: { color: color.text, width: setFontSize(2) }},
        axisLabel: { interval: 0, fontSize: '.2rem', color: color.text }
      }
    ],
    yAxis: [
      {
        name: '销量（ 斤 ）',
        type: 'value',
        position: 'right',
        show: true,
        nameTextStyle: { fontSize: setFontSize(18) },
        axisTick: { show: false },
        axisLine: { lineStyle: { color: color.line, width: setFontSize(2) }},
        splitLine: { show: true, lineStyle: { color: [color.line], opacity: 0.2, width: setFontSize(2), type: 'solid' }},
        axisLabel: { fontSize: setFontSize(16), color: color.text }
      },
      {
        name: '价格走势（ 元/斤 ）',
        type: 'value',
        position: 'left',
        nameTextStyle: { padding: [0, 0, 0, setFontSize(100)], fontSize: setFontSize(18) },
        axisTick: { show: false },
        axisLine: { lineStyle: { color: color.line, width: setFontSize(2) }},
        splitLine: { show: false, lineStyle: { color: [color.line], opacity: 0.2, width: setFontSize(1), type: 'dotted' }},
        axisLabel: { fontSize: setFontSize(16), color: color.text }
      }
    ],
    series: [
      {
        name: '销量（ 斤 ）',
        yAxisIndex: 1,
        type: 'bar',
        barWidth: '50%',
        barGap: '0%',
        itemStyle: { color: '#0096ff', borderWidth: 0, borderColor: '#0096ff' },
        data: datas
      },
      {
        name: '价格走势（ 元/斤 ）',
        xAxisIndex: 0,
        data: datas2,
        type: 'line',
        lineStyle: { color: '#ff9c00', width: setFontSize(2) },
        itemStyle: { opacity: 0 }
        // itemStyle: { color: '#ff9c00', borderWidth: setFontSize(10) }
      }
    ]
  }
}
)('white')

你好，我希望两个图表有不同的x轴，但是实际上是根据第一个x轴去渲染数据的，在配置中也没找到对应的配置，请问这个是我的配置问题还是没有这个配置项？