Crossfilter grouping keys based on values

I've have the following dataset.

[{..... att1: a, hits: 2},
{..... att1: a, hits: 2},
{..... att1: a, hits: 3},
{..... att1: b, hits: 2},
{..... att1: b, hits: 2},
{..... att1: c, hits: 9},
]

I want to create a bar chart where x values would be ranges '0-5', '5-10', '10+' and y values would be number of keys that fall in that range. ie. ('0-5', 1), ('5-10', 2), ('10+', 0)

---

Create a dimension that transforms your data into a set of ordinal values that match your buckets. Then group on that dimension. Your group will count the number of records that fall into each bucket.

var data = [{att1: 'a', hits: 2},
  {att1: 'a', hits: 2},
  {att1: 'a', hits: 3},
  {att1: 'b', hits: 2},
  {att1: 'b', hits: 2},
  {att1: 'c', hits: 9},
];
var cf = crossfilter(data);
var dim = cf.dimension(function(d) {
  if(d.hits <= 5) return '0-5';
  if(d.hits <= 10) return '5-10';
  return '10+'; 
});
var grp = dim.group();
console.log(grp.all());

Working example (check the console): https://jsfiddle.net/esjewett/u10h4xsu/2/

Then you can build your dc.js bar chart based on this.

var barChart = dc.barChart("#bar");

barChart.dimension(dim)
    .group(grp)
  .x(d3.scale.ordinal().domain(['0-5','5-10','10+']))
  .xUnits(dc.units.ordinal);

dc.renderAll();

Example with the bar chart: https://jsfiddle.net/esjewett/u10h4xsu/4/

链接地址: http://www.djcxy.com/p/32814.html

上一篇: 如何从crossfilter / reductio的组中创建一个组？

下一篇: Crossfilter基于值分组键