javascript - D3.js——如何通过 Javascript 更新数据集？

Question

我有一个包含 11 个不同变量的数据集(包含 12 列的 csv 文件)。我希望能够为我的散点图选择某一列，但我遇到了一些困难。请耐心等待，因为 JavaScript 不是我的强项(显然)。这是我尝试过的:

<div class="variables" id="fixedacidity" onclick="drawPlot('fixedacidity');">
    <h1>fixed acidity</h1>
</div>
<div class="variables" id="volatileacidity" onclick="drawPlot('volatileacidity');">
    <h1>volatile acidity</h1>
</div>
<div class="variables" id="citricacid" onclick="drawPlot('citricacid');">
    <h1>citric acid</h1>
</div>
<div class="variables" id="residualsugar" onclick="drawPlot('residualsugar');">
    <h1>residual sugar</h1>
</div>
etc ... 

我制作了一个调用drawPlot函数的简单菜单，但我在尝试正确传递变量时遇到了麻烦。

相关 d3/javascript:

function drawPlot(selectedVar){

$(".visarea").html("");

var wineVar = selectedVar;

var margin = {top: 20, right: 20, bottom: 30, left: 40},
    width = 860 - margin.left - margin.right,
    height = 350 - margin.top - margin.bottom;

var x = d3.scale.linear()
    .range([0, width]);

var y = d3.scale.linear()
    .range([height, 0])
    .domain([0,10]);

var color = d3.scale.category10();

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left").ticks(10);


var chart1 = d3.select(".visarea").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.csv("red.csv", function(error, data) {
  if (error) throw error;

  data.forEach(function(d) {
    d.wineVar = +d.wineVar;
    d.quality = +d.quality;
  });

  x.domain(d3.extent(data, function(d) { return d.wineVar; })).nice();
  y.domain([0,10]).nice();

  chart1.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis)
    .append("text")
      .attr("class", "label")
      .attr("x", width)
      .attr("y", -6)
      .style("text-anchor", "end")
      .text(wineVar);

  chart1.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("class", "label")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Rated Quality")

  chart1.selectAll(".red.dot")
      .data(data)
    .enter().append("circle")
      .attr("class", "red dot")
      .attr("r", 3)
      .attr("cx", function(d) { return x(d.wineVar); })
      .attr("cy", function(d) { return y(d.quality); })
      .style("fill", "red");

});
}

虽然变量被传递给函数，但 d.wineVar 正如预期的那样，不会返回所需的值，因此图表不会绘制正确的值。谁能推荐一个解决方法？这看起来很简单，但我花了几个小时试图弄清楚这一点。

red.csv 示例:

fixedacidity,volatileacidity,citricacid,residualsugar,chlorides,freesulfurdioxide,totalsulfurdioxide,density,pH,sulphates,alcohol,quality
7.4,0.7,0,1.9,0.076,11,34,0.9978,3.51,0.56,9.4,5
7.8,0.88,0,2.6,0.098,25,67,0.9968,3.2,0.68,9.8,5
7.8,0.76,0.04,2.3,0.092,15,54,0.997,3.26,0.65,9.8,5

我正在努力实现的目标的图像。第一个数据集，fixedacidity，绘制得很好。我在尝试让菜单正确显示其各自的数据集时遇到困难。 “额定质量”始终是 Y 轴的数据。

Answer 1

您的变量引用错误，此处:

  data.forEach(function(d) {
    d.wineVar = +d.wineVar;        //  <---------Here
    d.quality = +d.quality;
  });

更改方式:

  data.forEach(function(d) {
    d.wineVar = +d[wineVar];       // <----------Here
    d.quality = +d.quality;
  });