Question

我必须在d3图中绘制一个点，其中数据点值独立于X轴，只需要在y轴上绘制一条直线，因为只有一个数据点。

<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */

body { font: 12px Arial;}

path { 
    stroke: steelblue;
    stroke-width: 2;
    fill: none;
}

.axis path,
.axis line {
    fill: none;
    stroke: grey;
    stroke-width: 1;
    shape-rendering: crispEdges;
}

.legend {
    font-size: 16px;
    font-weight: bold;
    text-anchor: middle;
}

</style>
<body>

<!-- load the d3.js library -->    
<script src="https://d3js.org/d3.v4.min.js"></script>

<script>

// Set the dimensions of the canvas / graph
var margin = {top: 30, right: 20, bottom: 70, left: 50},
    width = 600 - margin.left - margin.right,
    height = 300 - margin.top - margin.bottom;

// Parse the date / time
var parseDate = d3.timeParse("%b %Y");

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

// Define the line
var priceline = d3.line()   
    .y(function(d) { return y(d.price); });

// Adds the svg canvas
var svg = d3.select("body")
    .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 + ")");

// Get the data
d3.csv("stocks.csv", function(error, data) {
    data.forEach(function(d) {

        d.price = +d.price;
    });

    // Scale the range of the data
var mindate = new Date(2017,1,1),
            maxdate = new Date(2017,2,2);
    x.domain(d3.extent([mindate, maxdate]));
    y.domain([0, d3.max(data, function(d) { return d.price; })]);

    // Nest the entries by symbol
    var dataNest = d3.nest()
        .key(function(d) {return d.symbol;})
        .entries(data);
    console.log(dataNest)
    // set the colour scale
    var color = d3.scaleOrdinal(d3.schemeCategory10);

    legendSpace = width/dataNest.length; // spacing for the legend

    // Loop through each symbol / key
    dataNest.forEach(function(d,i) { 

        svg.append("path")
            .attr("class", "line")
            .style("stroke", function() { // Add the colours dynamically
                return d.color = color(d.key); })
            .attr("d", priceline(d.values));

        // Add the Legend
        svg.append("text")
            .attr("x", (legendSpace/2)+i*legendSpace)  // space legend
            .attr("y", height + (margin.bottom/2)+ 5)
            .attr("class", "legend")    // style the legend
            .style("fill", function() { // Add the colours dynamically
                return d.color = color(d.key); })
            .text(d.key); 

    });

  // Add the X Axis
  svg.append("g")
      .attr("class", "axis")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));

  // Add the Y Axis
  svg.append("g")
      .attr("class", "axis")
      .call(d3.axisLeft(y));

});

</script>
</body>

请填写附件。该线应为Y轴上的水平线，完全独立于x轴。所以基本上我想基于不同的价格绘制多线图请在下面找到样本stocks.csv：

symbol  price
MSF 39.81
MSFT    36.35
MSFTz   28.37
MSFq    25.45
MSFTip  32.54

这样做会在screeenshot中出现以下错误：

使用d3

0 个答案: