Question

此示例适用于d3 v3版本。它是this sample的修剪版本，在与按钮交互时，画笔在新位置被动画化。

我实际上是尝试使用d3 v4版本this。

进行修剪以识别关注区域。修剪后的代码是

var margin = { top: 10, right: 10, bottom: 100, left: 40 },
      margin2 = { top: 430, right: 10, bottom: 20, left: 40 },
      width = 960 - margin.left - margin.right,
      height = 500 - margin.top - margin.bottom,
      height2 = 500 - margin2.top - margin2.bottom;

  var parseDate = d3.timeParse("%b %Y");

  var x = d3.scaleTime().range([0, width]),
      x2 = d3.scaleTime().range([0, width]),
      y = d3.scaleLinear().range([height, 0]),
      y2 = d3.scaleLinear().range([height2, 0]);

var xAxis = d3.axisBottom(x),
    xAxis2 = d3.axisBottom(x2),
    yAxis = d3.axisLeft(y);

  var brush = d3.brushX(x2)
    .on("brush end", brushed);

  var area1 = d3.area()
    .curve(d3.curveMonotoneX)
    .x(function(d) { return x(d.date); })
    .y0(height)
    .y1(function(d) { return y(d.price); });

var area2 = d3.area()
    .curve(d3.curveMonotoneX)
    .x(function(d) { return x2(d.date); })
    .y0(height2)
    .y1(function(d) { return y2(d.price); });



  // make some buttons to drive our zoom
  d3.select("body").append("div")
    .attr("id","btnDiv")
    .style('font-size','75%')
    .style("width","250px")
    .style("position","absolute")
    .style("left","5%")
    .style("top","200px")

  var btns = d3.select("#btnDiv").selectAll("button").data([2001, 2002, 2003, 2004])

  btns = btns.enter().append("button").style("display","inline-block")

  // fill the buttons with the year from the data assigned to them
  btns.each(function (d) {
    this.innerText = d;
  })

  btns.on("click", drawBrush);

  function drawBrush() {
    // define our brush extent to be begin and end of the year
    brush.extent([new Date(this.innerText + '-01-01'), new Date(this.innerText + '-12-31')])

    // now draw the brush to match our extent
    // use transition to slow it down so we can see what is happening
    // remove transition so just d3.select(".brush") to just draw
    brush(d3.select(".brush").transition());

    // now fire the brushstart, brushmove, and brushend events
    // remove transition so just d3.select(".brush") to just draw
    brush.event(d3.select(".brush").transition().delay(1000))
  }


  var svg = d3.select("body").append("svg")
      .attr("width", width + margin.left + margin.right)
      .attr("height", height + margin.top + margin.bottom);

  svg.append("defs").append("clipPath")
      .attr("id", "clip")
    .append("rect")
      .attr("width", width)
      .attr("height", height);

  var focus = svg.append("g")
      .attr("class", "focus")
      .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

  var context = svg.append("g")
      .attr("class", "context")
      .attr("transform", "translate(" + margin2.left + "," + margin2.top + ")");

  d3.csv("sp500.csv", type, function(error, data) {
  if (error) throw error;

  x.domain(d3.extent(data, function(d) { return d.date; }));
  y.domain([0, d3.max(data, function(d) { return d.price; })]);
  x2.domain(x.domain());
  y2.domain(y.domain());


    context.append("g")
        .attr("class", "x brush")
        .call(brush)
      .selectAll("rect")
        .attr("y", -6)
        .attr("height", height2 + 7);
  });

  function brushed() {
    x.domain(brush.empty() ? x2.domain() : brush.extent());
  }

  function type(d) {
    d.date = parseDate(d.date);
    d.price = +d.price;
    return d;
  }

svg {
  font: 10px sans-serif;
}

.area {
  fill: steelblue;
  clip-path: url(#clip);
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.brush .extent {
  stroke: #fff;
  fill-opacity: .125;
  shape-rendering: crispEdges;
}

<!DOCTYPE html>
<meta charset="utf-8">
<style>

svg {
  font: 10px sans-serif;
}

.area {
  fill: steelblue;
  clip-path: url(#clip);
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.brush .extent {
  stroke: #fff;
  fill-opacity: .125;
  shape-rendering: crispEdges;
}

</style>
<body>
<script src="http://d3js.org/d3.v4.js"></script>
</body>

请参阅fiddle以获取正确的错误。附在摘录

后，错误会有所不同

任何帮助都非常值得赞赏。

更新：错误是

d3.v4.js：12632未捕获TypeError：group.property不是函数

有没有人有预感新的API来解决点击此fiddle中的按钮的错误。如果可以为它更新小提琴，那将是非常棒的。或者至少让我知道修改后的API，因为样本适用于v3。

Answer 1

在上述示例之后，我遇到了相同的错误，并找到了您的问题。由于您的小提琴无法正常工作（无法访问CSV），因此我无法确认我的答案是否对您有用。但是它在本地对我有效。

在v4上它变得非常容易。只需调用brush.move(group, selection)即可以编程方式移动笔刷选择。但是，参数selection似乎是基于笔刷范围的相对坐标，因此，如果您的轴是日期/时间，则可能必须将日期转换为坐标号。

例如，我在定义画笔时传入了范围的参数。

let width  = 200;
let height = 80;
let x      = d3.scaleTime().range([0, width]);
let brush  = d3.brushX()
    .extent([[0, 0], [width, height]])
    .on("brush end", brushed);

context.append("g")
    .attr("class", "brush")
    .call(brush)
    .call(brush.move, x.range());

然后我修改了drawBrush（）函数，使其仅使用brush.move（）：

function drawBrush() {
    // Convert your dates to pixels along the brush's width.
    let start = x(new Date(this.innerText + '-01-01'));
    let end   = x(new Date(this.innerText + '-12-31'));

    // Alternatively, let's say the coordinates of your year is from 20% to 40% of your graph.
    // let start = 0.2 * width;
    // let end   = 0.4 * width;

    brush.move(context.select("g.brush").transition().delay(1000).duration(500), [start, end]);
}

不幸的是，此解决方案将打破drawBrush（）函数的两步过渡，并将其组合为一个动画。您必须自己进行其他修改。

d3 v4实现中d3-brush的JS错误

1 个答案: