javascript - d3js : How to select only x number of values from data

Question

我有一些数据格式如下:

var data = [
  {name: "A", rank: 0, c: 92}, 
  {name: "B", rank: 45, c: 99},
  {name: "C", rank: 89, c: 89},
  {name: "D", rank: 23, c: 99},
  {name: "E", rank: 56, c: 98}
];

我想找到此数据的一个子集，比如只说 3 个值。我不确定如何做到这一点是 d3js。我找到的解决方案主要基于数据的属性，例如:

data = data.filter(function(d){return +d.rank < 10});

但这给了我所有排名 < 10 的数据点，但我想根据一些用户输入限制数据的“大小”(数据点的数量)。

我该怎么做？

Answer 1

使用filter可能是这样的+ slice :

var data = [
  {name: "A", rank: 0, c: 92},

  {name: "B", rank: 45, c: 99},

  {name: "C", rank: 89, c: 89},

  {name: "D", rank: 23, c: 99},

  {name: "E", rank: 56, c: 98}
];
var size = 3; //user input size that is needed
var result = data.filter(function(d) {return (+d.rank > 10)}).slice(0,size)
console.log(result)