Question

我正在尝试使用类似于以下内容的JSON数据创建一个简单的多线图：

[
    {
        sampleDate: "2014-04-14",
        shortName: "PFOA",
        pfcLevel: "0.3500000"
    },
    {
        sampleDate: "2014-05-14",
        shortName: "PFOA",
        pfcLevel: "0.3200000"
    },
    {
        sampleDate: "2014-04-14",
        shortName: "PFOS",
        pfcLevel: "2.5000000"
    },
    {
        sampleDate: "2014-05-14",
        shortName: "PFOS",
        pfcLevel: "2.4000000"
    }
]

我显示基本的X和Y轴，但实际值行没有显示。查看DOM，path元素未显示d属性。

<path class="line" style="stroke: green;"></path>

代码如下：

<script>

  var data = <?php echo $wellSamples ?>;

  console.log(data);

  // 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;

  // Parse the date / time
  var parseDate = d3.time.format("%Y-%m-%d").parse;

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

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

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

  var line = d3.svg.line()
      .interpolate("basis")
      .x(function(d) { console.log(d.sampleDate); return x(d.sampleDate); })
      .y(function(d) { console.log(d.pfcLevel); return y(d.pfcLevel); });

  var svg = d3.select("#chart").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 + ")");

  x.domain(d3.extent(data, function(d) { return parseDate(d.sampleDate); }));
  y.domain(d3.extent(data, function(d) { return d.pfcLevel; }));

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

  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("PFC Level");


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

  pfc.append("path")
      .attr("class", "line")
      .attr("d", line)
      .style("stroke", "green");

</script>

Answer 1

这里有几个问题：

您的数据绑定无效。绑定数据然后调用.attr("d", line)，这将调用每个点上的行函数。它需要一个整数数组 - .attr("d", line(data))
您没有尝试从该数据创建多行。我猜你想要一条线＆＃34; shortName＆＃34;？您需要嵌套数据。
您的行x访问者调用.x(function(d) { return x(d.sampleDate); })，d.sampleDate从未转换为日期，但它仍然是一个字符串。

把这一切放在一起：

＆＃13;

<!DOCTYPE html>
<html>

  <head>
    <script data-require="d3@3.5.3" data-semver="3.5.3" src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.3/d3.js"></script>
    <link rel="stylesheet" href="style.css" />
    <script src="script.js"></script>
  </head>

  <body>
    <div id="chart"></div>
    <script>

  var data = [
    {
        sampleDate: "2014-04-14",
        shortName: "PFOA",
        pfcLevel: "0.3500000"
    },
    {
        sampleDate: "2014-05-14",
        shortName: "PFOA",
        pfcLevel: "0.3200000"
    },
    {
        sampleDate: "2014-04-14",
        shortName: "PFOS",
        pfcLevel: "2.5000000"
    },
    {
        sampleDate: "2014-05-14",
        shortName: "PFOS",
        pfcLevel: "2.4000000"
    }
];

  // Parse the date / time
  var parseDate = d3.time.format("%Y-%m-%d").parse;

  // clean up data
  data.forEach(function(d){
    d.sampleDate = parseDate(d.sampleDate);
    d.pfcLevel = +d.pfcLevel;
  });

  // nest data
  var nested_data = d3.nest()
    .key(function(d) { return d.shortName; })
    .entries(data);

  // 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.time.scale().range([0, width]);
  var y = d3.scale.linear().range([height, 0]);

  var xAxis = d3.svg.axis()
      .scale(x)
      .orient("bottom");

  var yAxis = d3.svg.axis()
      .scale(y)
      .orient("left");

  var line = d3.svg.line()
      .interpolate("basis")
      .x(function(d) { return x(d.sampleDate); })
      .y(function(d) { return y(d.pfcLevel); });

  var svg = d3.select("#chart").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 + ")");

  x.domain(d3.extent(data, function(d) { return d.sampleDate; }));
  y.domain(d3.extent(data, function(d) { return d.pfcLevel; }));

  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("PFC Level");

  // now we bind to nested_data, an array of arrays
  var pfc = svg.selectAll(".pfc")
      .data(nested_data)
      .enter()
      .append("g")
      .attr("class", "pfc");

  pfc.append("path")
      .attr("class", "line")
      .attr("d", function(d){
        // our inner array is d.values from the nesting
        return line(d.values);
      })
      .style("stroke", "green");


    </script>
  </body>

</html>

＆＃13;

D3多行图表行路径未显示：d属性缺失

1 个答案: