如何随着数据变化更新d3多线图表？

Question

我正在研究多线图 d3 图版本 7。我的数据就像

 data: GraphData[] = [
    {
      category: 'a',
      date: '2022-01-01',
      numberIssue: 10
    },
    {
      category: 'a',
      date: '2022-01-02',
      numberIssue: 20
    },
{
      category: 'b',
      date: '2022-01-01',
      numberIssue: 25
    },
    {
      category: 'b',
      date: '2022-01-02',
      numberIssue: 89
    }
  ];

我这样初始化我的 svg

margin = { top: 50, right: 50, bottom: 150, left: 50 };
  width = 700 - this.margin.left - this.margin.right;
  height = 500 - this.margin.top - this.margin.bottom;
  private colors = ['red', 'blue', 'yellow', 'green', 'brown'];

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

在 ngOnInit 方法下，我添加了用于缩放并绘制轴和线的代码

 const x = d3.scalePoint()
      .rangeRound([0, this.width]);

    // Add Y axis
    const y = d3.scaleLinear()
      .range([this.height, 0]);
    const xScale = d3
      .scalePoint()
      .domain(this.data.map((d: any) => { return d.date }))
      .range([0, this.width])
    // y-scale
    const yScale = d3
      .scaleLinear()
      .domain([0, d3.max(this.data.map((d: any) => d.numberIssue))])
      .range([this.height, 0]);
    // Group the entries by symbol
    const dataNest = Array.from(
      d3.group(this.data, d => d.category), ([key, value]) => ({ key, value })
    );

    var legendSpace = (this.width - 100) / dataNest.length; // spacing for the legend

    const line = d3
      .line()
      .defined(true)
      .x((d: any) => xScale(d.date) || 0)
      .y((d: any) => yScale(d.numberIssue));


    this.svg.selectAll('.xAxis').remove();
    this.svg.selectAll('.yAxis').remove();
    this.svg.selectAll('.line').remove();
    this.svg.selectAll('.legend').remove();
    this.svg.selectAll('.grid').remove();

    x.domain(this.data.map((d: any) => { return d.date }));
    y.domain([0, d3.max(this.data, ((d: any) => {
      return d.numberIssue;
    }))])
    this.svg.append("g")
      .attr('class', 'xAxis')
      .attr("transform", `translate(0, ${this.height})`)
      .call(d3.axisBottom(x).tickValues(this.data.map((d: any) => { return d.date })))
      .selectAll('text')
      .style('text-anchor', 'end')
      .style("font-size", 10)
      .attr('dx', '-.8em')
      .attr('dy', '.15em')
      .attr('transform', 'rotate(-65)');

    this.svg.append("g")
      .attr('class', 'yAxis')
      .call(
        d3.axisLeft(y).ticks(4).tickFormat(d3.format('d'))
      );
    dataNest.forEach((d1: any, i: any) => {

      // Data line

      this.svg.append("path")
        .datum([dataNest])
        .join("path")
        .attr("fill", "none")
        .attr("class", "line")
        .style("stroke", this.colors[i])
        .attr("d", line(d1.value));

      // Add the Legend
      this.svg.append("text")
        .attr("x", (legendSpace / 2) + i * legendSpace)  // space legend
        .attr("y", this.height + (this.margin.bottom / 2) + 15)
        .attr("class", "legend")    // style the legend
        .style("fill", this.colors[i])
        .text(DeSlugifyPipe.prototype.transform(d1.key));
    });

但是当重新渲染此组件时，它将绘制多线图第二次，不再更新上一次。那么有人可以帮忙解决这个问题吗？