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有没有办法以 d3-time-format 执行操作？

我有一个时间序列，我想将 D0 显示为“焦点日”，并且我想将前几天打印为负数，以打印时间轴，如 ...、D -2、D-1、 D 0, D 1, D 2 ...

我建立了假日期，以使 D0 对应于一年中的第一天，然后使用

%j

我得到以下信息：D 364，D 365，D 0，D 1

注意：这是在时间序列图中显示时间轴（在超集中），我只能输入一个简单的公式

有什么建议吗？

4

1 回答 1

2

d3-time-format 不会有这么具体的东西。为什么不创建自己的格式化程序？如果您使用的是时间刻度，请像这样定义您的 x 轴：

var xAxis = d3.axisBottom(x)
  .ticks(d3.timeDay.every(4)) // tick every 4 days
  .tickFormat(function(d){
    var diff = Math.round((d-dayZero)/(1000*60*60*24));
    return "D" + diff; // calc difference and display
  });

天差公式是从这里偷来的。

运行代码：

<!DOCTYPE html>
<meta charset="utf-8">
<style>
  /* set the CSS */
  
  body {
    font: 12px Arial;
  }
  
  path {
    stroke: steelblue;
    stroke-width: 2;
    fill: none;
  }

</style>

<body>

  <!-- load the d3.js library -->
  <script src="https://d3js.org/d3.v4.min.js"></script>

  <script>
    // data
        var data = [{
      "date": "2012-05-01T04:00:00.000Z",
      "close": 58.13
    }, {
      "date": "2012-04-30T04:00:00.000Z",
      "close": 53.98
    }, {
      "date": "2012-04-27T04:00:00.000Z",
      "close": 67
    }, {
      "date": "2012-04-26T04:00:00.000Z",
      "close": 89.7
    }, {
      "date": "2012-04-25T04:00:00.000Z",
      "close": 99
    }, {
      "date": "2012-04-24T04:00:00.000Z",
      "close": 130.28
    }, {
      "date": "2012-04-23T04:00:00.000Z",
      "close": 166.7
    }, {
      "date": "2012-04-20T04:00:00.000Z",
      "close": 234.98
    }, {
      "date": "2012-04-19T04:00:00.000Z",
      "close": 345.44
    }, {
      "date": "2012-04-18T04:00:00.000Z",
      "close": 443.34
    }, {
      "date": "2012-04-17T04:00:00.000Z",
      "close": 543.7
    }, {
      "date": "2012-04-16T04:00:00.000Z",
      "close": 580.13
    }, {
      "date": "2012-04-13T04:00:00.000Z",
      "close": 605.23
    }, {
      "date": "2012-04-12T04:00:00.000Z",
      "close": 622.77
    }, {
      "date": "2012-04-11T04:00:00.000Z",
      "close": 626.2
    }, {
      "date": "2012-04-10T04:00:00.000Z",
      "close": 628.44
    }, {
      "date": "2012-04-09T04:00:00.000Z",
      "close": 636.23
    }, {
      "date": "2012-04-05T04:00:00.000Z",
      "close": 633.68
    }, {
      "date": "2012-04-04T04:00:00.000Z",
      "close": 624.31
    }, {
      "date": "2012-04-03T04:00:00.000Z",
      "close": 629.32
    }, {
      "date": "2012-04-02T04:00:00.000Z",
      "close": 618.63
    }, {
      "date": "2012-03-30T04:00:00.000Z",
      "close": 599.55
    }, {
      "date": "2012-03-29T04:00:00.000Z",
      "close": 609.86
    }, {
      "date": "2012-03-28T04:00:00.000Z",
      "close": 617.62
    }, {
      "date": "2012-03-27T04:00:00.000Z",
      "close": 614.48
    }, {
      "date": "2012-03-26T04:00:00.000Z",
      "close": 606.98
    }];
    
    var dayZero = new Date("2012-04-13T04:00:00.000Z");
    
    data.forEach(function(d){
      d.date = new Date(d.date);
    });
  
    // Set the dimensions of the canvas / graph
    var margin = {
        top: 30,
        right: 20,
        bottom: 30,
        left: 50
      },
      width = 600 - margin.left - margin.right,
      height = 270 - margin.top - margin.bottom;

    // Set the ranges
    var x = d3.scaleTime().range([0, width]);
    var y = d3.scaleLinear().range([height, 0]);

    // Define the line
    var valueline = d3.line()
      .x(function(d) {
        return x(d.date);
      })
      .y(function(d) {
        return y(d.close);
      });

    // Adds the svg canvas
    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 + ")");

    // Scale the range of the data
    x.domain(d3.extent(data, function(d) {
      return d.date;
    }));
    y.domain([0, d3.max(data, function(d) {
      return d.close;
    })]);

    // Add the valueline path.
    svg.append("path")
      .attr("class", "line")
      .attr("d", valueline(data));
      
    // Define the axes
    var xAxis = d3.axisBottom(x)
      .ticks(d3.timeDay.every(4))
      .tickFormat(function(d){
        var diff = Math.round((d-dayZero)/(1000*60*60*24));
        return "D" + diff;
      }) 

    var yAxis = d3.axisLeft(y)
      .ticks(5);

    // Add the X Axis
    svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

    // Add the Y Axis
    svg.append("g")
      .attr("class", "y axis")
      .call(yAxis);
      
  </script>
</body>

于 2018-03-11T15:33:27.093 回答