D3:加载多个CSV文件,并使用平行坐标对其进行可视化

时间:2014-07-13 06:42:17

标签: javascript csv d3.js parallel-coordinates

我有4个csv文件(比如4个类),每个文件有100x200个元素(100个案例,200个特征)。 我需要使用平行坐标可视化其中一些功能(feature1,feature2,...,feature8;所以我将为每个csv文件提供100x8)。要识别这些类,我需要使用4种不同的颜色。

我已经有了可用于在一个csv文件中可视化数据(100x10)的并行坐标。代码如下:

    <style type="text/css">

      svg {
        font: 10px sans-serif;
      }

      .background path {
        fill: none;
        stroke: #ccc;
        stroke-opacity: .1;
        shape-rendering: crispEdges;
      }

      .foreground path {
        fill: none;
        stroke: steelblue;
        stroke-opacity: .7;
      }

      .brush .extent {
        fill-opacity: .3;
        stroke: #fff;
        shape-rendering: crispEdges;
      }

      .axis line, .axis path {
        fill: none;
        stroke: #000;
        shape-rendering: crispEdges;
      }

      .axis text {
        text-shadow: 0 1px 0 #fff;
        cursor: move;
      }

    </style>
  </head>
<body>
<script type="text/javascript">

        var m = [30, 10, 10, 10],
            w = 1300 - m[1] - m[3],
            h = 500 - m[0] - m[2];

        var x = d3.scale.ordinal().rangePoints([0, w], 1),
            y = {},
            dragging = {};

        var line = d3.svg.line(),
            axis = d3.svg.axis().orient("left"),
            background,
            foreground;

     var svg = d3.select("body").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] + ")");

      d3.csv("myData.csv")
      .row(function(d) {
        return {
        // Features that are needed to be visualize
         feature1   :  d.feature1,
         feature2   :  d.feature2,
         feature3   :  d.feature3,
         feature4   :  d.feature4,
         feature5   :  d.feature5,
         feature6   :  d.feature6,
         feature7   :  d.feature7,
         feature8   :  d.feature8
        };
      })
      .get(function(e, data) {
        x.domain(
            dimensions = d3.keys(data[0])
                            .filter(function(d) {
                                        return d != "source" && 
                                                (y[d] = d3.scale.linear()
                                                            .domain(d3.extent(data, function(p) { return +p[d]; }))
                                                            .range([h, 0]));
      }
      ));

      // Add grey background lines for context.
      background = svg.append("svg:g")
          .attr("class", "background")
        .selectAll("path")
          .data(data)
        .enter().append("svg:path")
          .attr("d", path);

      // Add blue foreground lines for focus.
      foreground = svg.append("svg:g")
          .attr("class", "foreground")
        .selectAll("path")
          .data(data)
        .enter().append("svg:path")
          .attr("d", path);

      // Add a group element for each dimension.
      var g = svg.selectAll(".dimension")
          .data(dimensions)
        .enter().append("svg:g")
          .attr("class", "dimension")
          .attr("transform", function(d) { return "translate(" + x(d) + ")"; })
          .call(d3.behavior.drag()
            .on("dragstart", function(d) {
              dragging[d] = this.__origin__ = x(d);
              background.attr("visibility", "hidden");
            })
            .on("drag", function(d) {
              dragging[d] = Math.min(w, Math.max(0, this.__origin__ += d3.event.dx));
              foreground.attr("d", path);
              dimensions.sort(function(a, b) { return position(a) - position(b); });
              x.domain(dimensions);
              g.attr("transform", function(d) { return "translate(" + position(d) + ")"; })
            })
            .on("dragend", function(d) {
              delete this.__origin__;
              delete dragging[d];
              transition(d3.select(this)).attr("transform", "translate(" + x(d) + ")");
              transition(foreground)
                  .attr("d", path);
              background
                  .attr("d", path)
                  .transition()
                  .delay(500)
                  .duration(0)
                  .attr("visibility", null);
            }));

      // Add an axis and title.
      g.append("svg:g")
          .attr("class", "axis")
          .each(function(d) { d3.select(this).call(axis.scale(y[d])); })
        .append("svg:text")
          .attr("text-anchor", "middle")
          .attr("y", -9)
          .text(String);

      // Add and store a brush for each axis.
      g.append("svg:g")
          .attr("class", "brush")
          .each(function(d) { d3.select(this).call(y[d].brush = d3.svg.brush().y(y[d]).on("brush", brush)); })
        .selectAll("rect")
          .attr("x", -8)
          .attr("width", 16);
    });

    function position(d) {
      var v = dragging[d];
      return v == null ? x(d) : v;
    }

    function transition(g) {
      return g.transition().duration(500);
    }

    // Returns the path for a given data point.
    function path(d) {
      return line(dimensions.map(function(p) { return [position(p), y[p](d[p])]; }));
    }

    // Handles a brush event, toggling the display of foreground lines.
    function brush() {
      var actives = dimensions.filter(function(p) { return !y[p].brush.empty(); }),
          extents = actives.map(function(p) { return y[p].brush.extent(); });
      foreground.style("display", function(d) {
        return actives.every(function(p, i) {
          return extents[i][0] <= d[p] && d[p] <= extents[i][1];
        }) ? null : "none";
      });
    }

        </script>
      </body>

我的样本数据也是这样的:

path,Ktype,label,CGX,CGY,C_1,C_2,C_3,C_4,total1,total2,totalI3,total4,feature1,feature2,feature3,feature4,feature5,feature6,feature7,feature8,feature9,feature10,feature11,feature12,A,B,C,D,feature13,feature14,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
    .\Mydata\Case1,k1,1,42,33,0,57.44534,0,52597,71,16,10,276,4038,3789.631,0.6173469,0.6499337,2.103316,0.6661285,1.065539,248.3694,0.630161,0.000192848,0.9999996,0.000642777,1,0,0,1,9.60E-05,3136.698,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
    .\Mydata\Case2,k1,2,163,29,0,43.28862,0,49050,71,16,10,248,2944,2587.956,0.5726808,0.5681185,2.130387,0.601512,1.137578,356.0444,0.6335613,0.000327267,1.000029,0.001271235,1,0,0,1,0.00010854,2676.418,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
    .\Mydata\Case3,k1,3,774,19,0,45.26291,0,53455,71,16,10,212,2366,1982.547,0.408179,0.4579566,1.994296,0.6615351,1.193415,383.4534,0.7153812,0.000264522,1.000031,0.001210507,1,1,0,0,9.54E-05,3221.289,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
    .\Mydata\Case4,k1,4,1116,25,0,80.76469,0,57542,71,16,10,284,3908,3453.988,0.3549117,0.4811547,1.982244,0.6088744,1.131446,454.0122,0.6166388,0.000314288,0.9999836,0.00129846,0,1,1,0,0.000140592,2143.42,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
    .\Mydata\Case5,k1,5,1364,59,1,52.96776,0,49670,71,16,10,228,2725,2642.675,0.4328255,0.475517,1.859871,0.6587288,1.031152,82.32471,0.5775694,0.000466264,0.9999803,0.001765345,0,1,1,0,0.00012014,2439.636,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

现在,我有两个问题:

首先,我不知道如何同时加载4个csv文件?将来,我可能需要增加类的数量(即增加需要可视化的csv文件的数量),因此可能组合csv文件,并加载一个csv文件并不是一个好主意。我该怎么办呢?

其次,我应该如何为与他们所属的csv文件相关的线条着色?

1 个答案:

答案 0 :(得分:3)

要异步加载多个文件,您可以使用排队库,例如queue.js

然后,一旦加载了文件,您就可以在单个重叠的g组元素中呈现它们,并将颜色应用于整个组,例如,基于文件加载顺序的索引

以下是未经测试且未完成的解决方案,可能会为您提供一些线索:

var q = queue(), // create the queue
    dataSources = [ // your data sources
        'dataSource1.csv',
        'dataSource2.csv',
        ...
    ],
    colorScale = d3.scale.category20(); // categorical color scale bundled with d3

// Returns a different color for elements based on their index in the data:
function colorByIndex(d, i) {
    return colorScale(i);
}

// Go through each data source and add it to the queue:
dataSources.forEach(function (source) {
    q.defer(function (callback) {
        d3.csv(source, callback);
    });
});

// Wait for all requests to be completed:
q.awaitAll(function (error, results) {
    // TODO: check for errors!
    // Select and create groups of elements that are to be colored differently:
    d3.selectAll('.group').data(results) // array of arrays
        .append('g')
        .style('color', colorByIndex) // this applies color to the entire group
            .selectAll('???') // whatever you render, paths perhaps
            .data(function (d) { return d; })
            ...
            // at this point the d variable is an array of data
            // straight from each of your csv files, you can
            // proceed rendering as you usually do and there's
            // no longer need to apply any colors
});

或者,您可以将results合并在一个数组中,并使用指示文件来标记每个单独的行,如下所示:

['dataSource1.csv', 'a1', 'b1', 'c1', ...],
['dataSource1.csv', 'a2', 'b2', 'c2', ...],
['dataSource2.csv', 'a3', 'b3', 'c3', ...],
...

然后根据指标的值应用颜色。