在开始日期和结束日期之间附加一行

Question

基本上我使用 D3 创建基于甘特图的图表。我有一个 .json 文件，其中包含我的数据，并且能够创建显示适当信息的 x-y 刻度。我遇到的这个问题是，我希望这些行在数组中的 15 个项目中的每一个的开始日期和结束日期之间延伸，所有这些都包含名称、开始日期和结束日期。当我打开图表时，信息会显示，但它只显示一条从 y 轴开始的实线，它一直延伸到个人开始日期。

在尝试补救这种情况时，我意识到通过将今天的日期添加为数组中 startDate 下的新项目，任何日期为今天的项目都完全按照我的要求执行，而其他项目则不然。我不确定是什么原因造成的，但推测这可能与日期的解析方式有关？完全不知所措，因为我还是 d3 的新手。

// employment.json 
[
    {
      "name": "Placeholder 1",
      "position": "Occupation 1",
      "startDate": "2013-09-05",
      "endDate": "2019-08-01"
    },
    {
      "name": "Placeholder 2",
      "position": "Occupation 1",
      "startDate": "2013-09-05",
      "endDate": "2018-10-31"
    },
    {
      "name": "Placeholder 3",
      "position": "Occupation 1",
      "startDate": "2013-11-05",
      "endDate": "2014-03-03"
    },
    {
      "name": "Placeholder 4",
      "position": "Occupation 1",
      "startDate": "2014-05-09",
      "endDate": "2015-04-06"
    },
    {
      "name": "Placeholder 5",
      "position": "Occupation 1",
      "startDate": "2014-12-01",
      "endDate": "2019-08-01"
    },
    {
      "name": "Placeholder 6",
      "position": "Occupation 1",
      "startDate": "2015-04-20",
      "endDate": "2016-10-18"
    },
    {
      "name": "Placeholder 7",
      "position": "Occupation 1",
      "startDate": "2016-05-05",
      "endDate": "2019-07-31"
    },
    {
      "name": "Placeholder 8",
      "position": "Occupation 1",
      "startDate": "2016-11-07",
      "endDate": "2017-05-12"
    },
    {
      "name": "Placeholder 9",
      "position": "Occupation 1",
      "startDate": "2017-09-18",
      "endDate": "2019-08-01"
    },
    {
      "name": "Placeholder 10",
      "position": "Occupation 1",
      "startDate": "2018-01-11",
      "endDate": "2018-09-20"
    },
    {
      "name": "Placeholder 11",
      "position": "Occupation 1",
      "startDate": "2018-04-17",
      "endDate": "2018-07-24"
    },
    {
      "name": "Placeholder 12",
      "position": "Occupation 1",
      "startDate": "2018-07-04",
      "endDate": "2018-08-30"
    },
    {
      "name": "Placeholder 13",
      "position": "Occupation 1",
      "startDate": "2018-07-09",
      "endDate": "2019-08-01"
    },
    {
      "name": "Placeholder 14",
      "position": "Occupation 1",
      "startDate": "2019-01-16",
      "endDate": "2019-08-01"
    },
    {
      "name": "Placeholder 15",
      "position": "Occupation 1",
      "startDate": "2019-04-01",
      "endDate": "2019-08-01"
    },
    {
      "name": "Total Time",
      "position": "Occupation 1",
      "startDate": "2013-09-05",
      "endDate": "2019-08-01"
     }
  ]

// app.js

var margin = {top: 10, right: 30, bottom: 80, left: 100},
    width = 960 - margin.left - margin.right,
    height = 560 - margin.top - margin.bottom;

var svg = d3.select("#employment_history")
  .append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform",
          "translate(" + margin.left + "," + margin.top + ")");

d3.json('json/employment.json', function(error, data) {
    if (error) {
      return console.warn(error);
    } else {
      console.log(data);
    }

    var x = d3.scaleBand()
        .range([0, width ])
        .domain(data.map(function(d) { return d.startDate }, 
data.map(function(d) { return d.endDate })))
        .padding(0.2);
    svg.append('g')
        .attr("transform", "translate(0," + height + ")")
        .call(d3.axisBottom(x))
        .selectAll("text")
        .attr("transform", "translate(-10,0)rotate(-45)")
        .style("text-anchor", "end");

    var y = d3.scaleBand()
        .range([ 0, height ])
        .domain(data.map(function(d) { return d.name; }))
        .padding(2);
      svg.append("g")
        .call(d3.axisLeft(y))

  // Lines
  svg.selectAll("myLine")
    .data(data)
    .enter()
    .append("line")
      .attr("x1", function(d) { return x(d.startDate); })
      .attr("x2", function(d) { return x(d.endDate); })
      .attr("y1", function(d) { return y(d.name); })
      .attr("y2", function(d) { return y(d.name); })
      .attr("stroke", "orange")
      .attr("stroke-width", "2px")
  })

控制台中没有显示错误，它提供了一个从 Y 轴开始并延伸到开始日期的图表，而不是从开始日期开始并连接到结束日期。

我正在尝试完成的示例以及创建此示例所遵循的示例是：https://www.d3-graph-gallery.com/graph/lollipop_cleveland.html

Answer 1

你的体重秤错误。

这里的主要问题是 x 轴，它应该使用 时间刻度 ，而不是波段刻度。那么，让我们看看必要的更改：

首先，解析数据数组中的日期：

const parse = d3.timeParse("%Y-%m-%d");

data.forEach(function(d) {
  d.startDate = parse(d.startDate);
  d.endDate = parse(d.endDate);
});

然后，设置时间尺度，根据日期计算域：

var x = d3.scaleTime()
  .range([0, width])
  .domain([d3.min(data, function(d) {
    return d.startDate
  }), d3.max(data, function(d) {
    return d.endDate
  })]);

最后，你的 y 尺度应该是 point 尺度，而不是 band 尺度：

var y = d3.scalePoint()
  .range([0, height])
  .domain(data.map(function(d) {
    return d.name;
  }))
  .padding(0.5);

这是工作代码（在较小的 SVG 中）：

const data = [{
    "name": "Placeholder 1",
    "position": "Occupation 1",
    "startDate": "2013-09-05",
    "endDate": "2019-08-01"
  },
  {
    "name": "Placeholder 2",
    "position": "Occupation 1",
    "startDate": "2013-09-05",
    "endDate": "2018-10-31"
  },
  {
    "name": "Placeholder 3",
    "position": "Occupation 1",
    "startDate": "2013-11-05",
    "endDate": "2014-03-03"
  },
  {
    "name": "Placeholder 4",
    "position": "Occupation 1",
    "startDate": "2014-05-09",
    "endDate": "2015-04-06"
  },
  {
    "name": "Placeholder 5",
    "position": "Occupation 1",
    "startDate": "2014-12-01",
    "endDate": "2019-08-01"
  },
  {
    "name": "Placeholder 6",
    "position": "Occupation 1",
    "startDate": "2015-04-20",
    "endDate": "2016-10-18"
  },
  {
    "name": "Placeholder 7",
    "position": "Occupation 1",
    "startDate": "2016-05-05",
    "endDate": "2019-07-31"
  },
  {
    "name": "Placeholder 8",
    "position": "Occupation 1",
    "startDate": "2016-11-07",
    "endDate": "2017-05-12"
  },
  {
    "name": "Placeholder 9",
    "position": "Occupation 1",
    "startDate": "2017-09-18",
    "endDate": "2019-08-01"
  },
  {
    "name": "Placeholder 10",
    "position": "Occupation 1",
    "startDate": "2018-01-11",
    "endDate": "2018-09-20"
  },
  {
    "name": "Placeholder 11",
    "position": "Occupation 1",
    "startDate": "2018-04-17",
    "endDate": "2018-07-24"
  },
  {
    "name": "Placeholder 12",
    "position": "Occupation 1",
    "startDate": "2018-07-04",
    "endDate": "2018-08-30"
  },
  {
    "name": "Placeholder 13",
    "position": "Occupation 1",
    "startDate": "2018-07-09",
    "endDate": "2019-08-01"
  },
  {
    "name": "Placeholder 14",
    "position": "Occupation 1",
    "startDate": "2019-01-16",
    "endDate": "2019-08-01"
  },
  {
    "name": "Placeholder 15",
    "position": "Occupation 1",
    "startDate": "2019-04-01",
    "endDate": "2019-08-01"
  },
  {
    "name": "Total Time",
    "position": "Occupation 1",
    "startDate": "2013-09-05",
    "endDate": "2019-08-01"
  }
];

var margin = {
    top: 10,
    right: 30,
    bottom: 80,
    left: 100
  },
  width = 600 - margin.left - margin.right,
  height = 400 - margin.top - margin.bottom;

var svg = d3.select("body")
  .append("svg")
  .attr("width", width + margin.left + margin.right)
  .attr("height", height + margin.top + margin.bottom)
  .append("g")
  .attr("transform",
    "translate(" + margin.left + "," + margin.top + ")");

const parse = d3.timeParse("%Y-%m-%d");

data.forEach(function(d) {
  d.startDate = parse(d.startDate);
  d.endDate = parse(d.endDate);
});

var x = d3.scaleTime()
  .range([0, width])
  .domain([d3.min(data, function(d) {
    return d.startDate
  }), d3.max(data, function(d) {
    return d.endDate
  })]);

svg.append('g')
  .attr("transform", "translate(0," + height + ")")
  .call(d3.axisBottom(x))
  .selectAll("text")
  .attr("transform", "translate(-10,0)rotate(-45)")
  .style("text-anchor", "end");

var y = d3.scalePoint()
  .range([0, height])
  .domain(data.map(function(d) {
    return d.name;
  }))
  .padding(0.5);

svg.append("g")
  .call(d3.axisLeft(y))

// Lines
svg.selectAll("myLine")
  .data(data)
  .enter()
  .append("line")
  .attr("x1", function(d) {
    return x(d.startDate);
  })
  .attr("x2", function(d) {
    return x(d.endDate);
  })
  .attr("y1", function(d) {
    return y(d.name);
  })
  .attr("y2", function(d) {
    return y(d.name);
  })
  .attr("stroke", "orange")
  .attr("stroke-width", "2px")

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

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