Question

我只是想附加mbostocks饼图示例的标签，但由于某种原因我无法使其工作。

我基本上只是想结合他的两个例子（pie update，pie labels），所以我试图实现这个代码;

var g = svg.selectAll(".arc")
      .data(pie(data))
    .enter().append("g")
      .attr("class", "arc");

  g.append("path")
      .attr("d", arc)
      .style("fill", function(d) { return color(d.data.apples); });

  g.append("text")
      .attr("transform", function(d) { return "translate(" + arc.centroid(d) + ")"; })
      .attr("dy", ".35em")
      .text(function(d) { return d.data.apples; });
});

在他的饼图更新示例中加入此变量;

var path = svg.datum(data).selectAll("path")
      .data(pie)
    .enter().append("path")
      .attr("fill", function(d, i) { return color(i); })
      .attr("d", arc)
      .each(function(d) { this._current = d; }); // store the initial angles

这是我尝试的一部分，希望有人可以解决我遇到的问题。

http://plnkr.co/edit/e05kKjB8KWGqRteh8OdS?p=preview

我的尝试代码;

var width = 960,
    height = 500,
    radius = Math.min(width, height) / 2;

var color = d3.scale.category20();

var pie = d3.layout.pie()
    .value(function(d) { return d.apples; })
    .sort(null);

var arc = d3.svg.arc()
    .innerRadius(radius - 100)
    .outerRadius(radius - 20);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");

d3.tsv("data.tsv", type, function(error, data) {
  if (error) throw error;

/*  var path = svg.datum(data).selectAll("path")
      .data(pie)
    .enter().append("path")
      .attr("fill", function(d, i) { return color(i); })
      .attr("d", arc)
      .each(function(d) { this._current = d; }); // store the initial angles*/


  var g = svg.datum(data).selectAll(".arc")
      .data(pie)
    .enter().append("g")
      .attr("class", "arc")

  g.append("path")
      .attr("d", arc)
      .style("fill", function(d) { return color(d.data.apples); })
            .each(function(d) { this._current = d; }); // store the initial angles


  g.append("text")
      .attr("transform", function(d) { return "translate(" + arc.centroid(d) + ")"; })
      .attr("dy", ".35em")
      .text(function(d) { return d.data.apples; });

  d3.selectAll("input")
      .on("change", change);

  var timeout = setTimeout(function() {
    d3.select("input[value=\"oranges\"]").property("checked", true).each(change);
  });

  function change() {
    var value = this.value;
    clearTimeout(timeout);
    pie.value(function(d) { return d[value]; }); // change the value function
    path = g.data(pie); // compute the new angles
    path.transition().duration(750).attrTween("d", arcTween); // redraw the arcs
  }
});

function type(d) {
  d.apples = +d.apples;
  d.oranges = +d.oranges;
  return d;
}

// Store the displayed angles in _current.
// Then, interpolate from _current to the new angles.
// During the transition, _current is updated in-place by d3.interpolate.
function arcTween(a) {
  var i = d3.interpolate(this._current, a);
  this._current = i(0);
  return function(t) {
    return arc(i(t));
  };
}

Answer 1

当您从path的集合转移到包含g和path的{{1}}集合时，您没有更新转换以在路径上运行。它正试图在text上应用转换。更正后的代码：

运行代码：

function change() {
  var value = this.value;
  pie.value(function(d) { return d[value]; }); 
  g = g.data(pie); 
  g.select("path") //<-- operate on the paths in the g
    .transition()
    .duration(750)
    .attrTween("d", arcTween);
}

var width = 500,
  height = 500,
  radius = Math.min(width, height) / 2;

var color = d3.scale.category20();

var pie = d3.layout.pie()
  .value(function(d) {
    return d.apples;
  })
  .sort(null);

var arc = d3.svg.arc()
  .innerRadius(radius - 100)
  .outerRadius(radius - 20);

var svg = d3.select("body").append("svg")
  .attr("width", width)
  .attr("height", height)
  .append("g")
  .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");

var data = [{
  "apples": 53245,
  "oranges": 200
}, {
  "apples": 28479,
  "oranges": 200
}, {
  "apples": 19697,
  "oranges": 200
}, {
  "apples": 24037,
  "oranges": 200
}, {
  "apples": 40245,
  "oranges": 200
}];

var g = svg.datum(data).selectAll(".arc")
  .data(pie)
  .enter().append("g")
  .attr("class", "arc");

var path = g.append("path")
  .attr("d", arc)
  .style("fill", function(d) {
    return color(d.data.apples);
  })
  .each(function(d) {
    this._current = d;
  }); // store the initial angles

var text = g.append("text")
  .attr("transform", function(d) {
    return "translate(" + arc.centroid(d) + ")";
  })
  .attr("dy", ".35em")
  .text(function(d) {
    return d.data.apples;
  });

d3.selectAll("input")
  .on("change", change);

function change() {
  var value = this.value;
  pie.value(function(d) {
    return d[value];
  }); // change the value function
  g = g.data(pie); // compute the new angles
  g.select("path")
    .transition()
    .duration(750)
    .attrTween("d", arcTween); // redraw the arcs
  g.select("text")
    .style("opacity", 0)
    .attr("transform", function(d) {
      return "translate(" + arc.centroid(d) + ")";
    })
    .text(function(d) {
      return d.data[value];
    })
    .transition()
    .duration(1000)
    .style("opacity", 1);
}

function type(d) {
  d.apples = +d.apples;
  d.oranges = +d.oranges;
  return d;
}

// Store the displayed angles in _current.
// Then, interpolate from _current to the new angles.
// During the transition, _current is updated in-place by d3.interpolate.
function arcTween(a) {
  var i = d3.interpolate(this._current, a);
  this._current = i(0);
  return function(t) {
    return arc(i(t));
  };
}

使用标签更新饼图（d3）

1 个答案: