dc.js - Crossfilter示例中的合成图

Question

从付款示例交叉过滤器(https://github.com/square/crossfilter/wiki/API-Reference)开始，如何为每种付款类型(标签，签证，现金)创建一个折线图的综合图？

Answer 1

我假设您想随时间显示每个付款totals的付款date(即type维度)。

var payments = crossfilter([...]);

var dateDimension = payments.dimension(function(d) { return new Date(d.date); });

为每种付款类型(标签，签证，现金)创建一组付款总计

var totalForType = function(type) {
  return function(d) {
    return d.type === type ? d.total : null;
  };
};

var tabTotalsGroup  = dateDimension.group().reduceSum(totalForType('tab'));
var visaTotalsGroup = dateDimension.group().reduceSum(totalForType('visa'));
var cashTotalsGroup = dateDimension.group().reduceSum(totalForType('cash'));

定义一个合成图，并使用组来定义3个折线图作为合成图的一部分。

var compositeChart = dc.compositeChart('#composite-chart');
compositeChart
  ...
  .x(d3.time.scale().domain([new Date("2011-11-14T16:15:00Z"), new Date("2011-11-14T17:45:00Z")]))
  .dimension(dateDimension)
  .compose([
    dc.lineChart(compositeChart).group(tabTotalsGroup, 'tab').colors(['#ffaa00']),
    dc.lineChart(compositeChart).group(visaTotalsGroup, 'visa').colors(['#aa00ff']),
    dc.lineChart(compositeChart).group(cashTotalsGroup, 'cash').colors(['#00aaff'])
  ]);

 dc.renderAll();

完整示例:http://plnkr.co/edit/rhDURrDfeSvVqEnQR9L1?p=preview