如何使用 dc.js 创建饼图

Question

我正在使用基于 d3 和 crossfilter 的 Dimensional Charting javascript 库 dc.js 制作饼图。我是 dc.js 库的新手。我正在尝试使用 csv 文件显示饼图。我无法理解如何按照 csv 格式创建饼图。

我的 csv 列格式是

 Age_19_Under   Age_19_64   Age_65_84   Age_85_and_Over
    26.9              62.3            9.8               0.9
    23.5              60.3            14.5              1.8
    24.3              62.5            11.6              1.6
    24.6              63.3            10.9              1.2
    24.5              62.1            12.1              1.3
    24.7              63.2            10                2.2
    25.6              58.5            13.6              2.4
    24.1              61.6            12.7              1.5
    24.8              59.5            13.5              2.2

我想画下图：

Answer 1

根本问题是您的数据“形状”不适合您想要的图表类型。您希望当前列标题实际存在于您的数据中，以便您可以按它们进行分组。我怀疑有一种更优雅的方式来重塑您的数据，但我在下面输入的内容应该很容易理解。一旦这些标签是实际数据而不是元数据，剩下的就很简单了。

var experiments = [
    { Age_19_Under: 26.9, Age_19_64: 62.3, Age_65_84: 9.8, Age_85_and_Over: 0.9 },
    { Age_19_Under: 23.5, Age_19_64: 60.3, Age_65_84: 14.5, Age_85_and_Over: 1.8 },
    { Age_19_Under: 24.3, Age_19_64: 62.5, Age_65_84: 11.6, Age_85_and_Over: 1.6 },
    { Age_19_Under: 24.6, Age_19_64: 63.3, Age_65_84: 10.9, Age_85_and_Over: 1.2 },
    { Age_19_Under: 24.5, Age_19_64: 62.1, Age_65_84: 12.1, Age_85_and_Over: 1.3 },
    { Age_19_Under: 24.7, Age_19_64: 63.2, Age_65_84: 10.0, Age_85_and_Over: 2.2 },
    { Age_19_Under: 25.6, Age_19_64: 58.5, Age_65_84: 13.6, Age_85_and_Over: 2.4 },
    { Age_19_Under: 24.1, Age_19_64: 61.6, Age_65_84: 12.7, Age_85_and_Over: 1.5 },
    { Age_19_Under: 24.8, Age_19_64: 59.5, Age_65_84: 13.5, Age_85_and_Over: 2.2 },
];

// Reshape the data 
var categoryList = new Array();
experiments.forEach(function (exp) {
    categoryList.push({ Category: "Age_19_Under", Value: exp.Age_19_Under });
    categoryList.push({ Category: "Age_19_64", Value: exp.Age_19_64 });
    categoryList.push({ Category: "Age_65_84", Value: exp.Age_65_84 });
    categoryList.push({ Category: "Age_85_and_Over", Value: exp.Age_85_and_Over });
});

// Setup crossfilter
var ndx = crossfilter(categoryList);
var categoryDim = ndx.dimension(function (d) { return d.Category; });
var valueSumGroup = categoryDim.group().reduceSum(function (d) { return d.Value; });

// Create the chart
var pieChart = dc.pieChart("#chartid");
pieChart
    .dimension(categoryDim)
    .group(valueSumGroup)
    .radius(100)
;

dc.renderAll();