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我无法弄清楚为什么我的数据没有绘制在我创建的折线图上。我正在使用以年为单位的时间尺度，并设法使图表的框架按预期呈现（X 轴值显示为年）。但是，数据没有绘制。这是我的代码（console.log 输出显示在脚本下方）：

// define dimensions of graph
    var m = [40, 120, 40, 120]; // margins
    var w = 1000 - m[1] - m[3];  // width
    var h = 400 - m[0] - m[2]; // height


d3.csv("national-debt-2013.csv", function(data) {

    var year = data.map(function(d){return d.year;}).reverse();
    var nomGDP = data.map(function(d){return +d.nominalGDPMillions;}).reverse();
    console.log("year", year);
    console.log("nomGDP", nomGDP);

// create axes
    var parse = d3.time.format("%Y").parse;

    var x = d3.time.scale().domain([parse(year[0]),parse(year[year.length - 1])]).range([0, w]),
      xAxis = d3.svg.axis().scale(x).tickSize(-h).tickSubdivide(true),

      y1 = d3.scale.linear().domain([0, d3.max(nomGDP)]).range([h, 0]),
      yAxisLeft = d3.svg.axis().scale(y1).ticks(4).orient("left"),

      console.log("x domain", x.domain());
      console.log("x range", x.range());
      console.log("y1 domain", y1.domain());
      console.log("y range", y1.range());


// create a line function that can convert data[] into x and y points
    var line1 = d3.svg.line()
      // assign the X function to plot our line as we wish
      .x(function(d,i) { 
        // verbose logging to show what's actually being done
         console.log('Plotting X1 value for data point: ' + d + ' using index: ' + year[i] + ' to be at ( x(i) ) : ' + x(i) + ' using our xScale.');
        // return the X coordinate where we want to plot this datapoint
        return year[i];
      })
      .y(function(d,i) { 
        // verbose logging to show what's actually being done
        console.log('Plotting Y1 value for data point: ' + d + ' to be at ( y1(d) ): ' + y1(d) + " using our y1Scale.");
        // return the Y coordinate where we want to plot this datapoint
        return y1(d); 
      })


// Add an SVG element with the desired dimensions and margin.
      var graph = d3.select("#graph").append("svg:svg")
            .attr("width", w + m[1] + m[3])
            .attr("height", h + m[0] + m[2])
          .append("svg:g")
            .attr("transform", "translate(" + m[3] + "," + m[0] + ")");


// Add the x-axis.
      graph.append("svg:g")
            .attr("class", "x axis")
            .attr("transform", "translate(0," + h + ")")
            .call(xAxis);


// Add the y-axis to the left
      graph.append("svg:g")
            .attr("class", "y axis axisLeft")
            .attr("transform", "translate(-15,0)")
            .call(yAxisLeft);

// add lines
      // do this AFTER the axes above so that the line is above the tick-lines
        graph.append("svg:path")
          .attr("d", function(d) { return line1(nomGDP); })
          .attr("class", "data1");

})

console.log 输出：

year 
["1911", "1912", "1913", "1914", "1915", "1916", "1917", "1918", "1919", "1920", "1921", "1922"...]

nomGDP 
[34675, 37745, 39517, 36831, 39048, 50117, 60278, 76567, 79090, 89246, 74314, 74140, 86238...]

x domain 
[Sun Jan 01 1911 00:00:00 GMT-0500 (EST), Tue Jan 01 2013 00:00:00 GMT-0500 (EST)]

x range [0, 760]

y1 domain [0, 16244600] 

y range [320, 0] 


Plotting X1 value for data point: 34675 using index: 1911 to be at ( x(i) ) : 439.60279328609266 using our xScale. bloch-new.html:150
Plotting Y1 value for data point: 34675 to be at ( y1(d) ): 319.3169422454231 using our y1Scale. bloch-new.html:157
Plotting X1 value for data point: 37745 using index: 1912 to be at ( x(i) ) : 439.6027932863288 using our xScale. bloch-new.html:150
Plotting Y1 value for data point: 37745 to be at ( y1(d) ): 319.25646676434013 using our y1Scale. bloch-new.html:157
...
Plotting X1 value for data point: 15533800 using index: 2011 to be at ( x(i) ) : 439.60279330970303 using our xScale. bloch-new.html:150
Plotting Y1 value for data point: 15533800 to be at ( y1(d) ): 14.001945261810022 using our y1Scale. bloch-new.html:157
Plotting X1 value for data point: 16244600 using index: 2012 to be at ( x(i) ) : 439.60279330993916 using our xScale. bloch-new.html:150
Plotting Y1 value for data point: 16244600 to be at ( y1(d) ): 0 using our y1Scale.

从上面的控制台输出中可以看出，数据仅绘制在 X 值 439 处。有什么想法吗？域和范围输出似乎正确。

IMG

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1 回答 1

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目前，您的代码将年份的字符串作为该行的 x 坐标返回。您需要将其传递给您正确设置的秤。这也需要将年份解析为Date. 所以总的来说，你的代码看起来像这样。

.x(function(d, i) {
  return x(parse(year[i]));
})

一般来说，更多的 D3 方法是将年份和值放在一个数组中，然后将其传递给.data()函数。然后你的线函数看起来像

var line = d3.svg.line()
             .x(function(d) { return x(d.year); })
             .y(function(d) { return y(d.nomGDP); });

以及添加该行的代码

graph.selectAll("path").data([data]).enter()
     .append("path")
     .attr("d", line);
于 2013-10-08T15:54:40.250 回答