ネストされた配列の最大長の検索

Question

ノードとエッジの内側にそれぞれソース、ターゲット、役員の配列を持つ配列があり、役員配列の長さの尺度を作成したいと考えています。

のように、配列がどのように見えるか

var officersScale = d3.scale.linear() 
             .domain([1, d3.max(dataset.edges.officers.length, function(d) { return d[0]; })]) 
             .range([1,10]); 

：Firsth事はまず、あなたのデータが有効でない

var dataset = {"nodes":[{"name":"Anglo American plc"},{"name":"Associated British Foods plc"},{"name":"Admiral Group plc"},{"name":"ARM Holdings plc"},{"name":"Aviva plc"},{"name":"BAE Systems plc"},{"name":"Barclays PLC"},{"name":"British American Tobacco p.l.c."},{"name":"The Berkeley Group Holdings plc"},{"name":"BHP Billiton plc"},{"name":"BP p.l.c."},{"name":"BT Group plc"},{"name":"Centrica plc"},{"name":"Compass Group PLC"},{"name":"Direct Line Insurance Group PLC"},{"name":"easyJet plc"},{"name":"International Consolidated Airlines Group, S.A."},{"name":"3i Group plc"},{"name":"Intertek Group plc"},{"name":"Lloyds Banking Group plc"},{"name":"Merlin Entertainments plc"},{"name":"Pearson plc"},{"name":"Reckitt Benckiser Group plc"},{"name":"Royal Dutch Shell plc"},{"name":"Rexam PLC"},{"name":"Rio Tinto plc"},{"name":"SABMiller plc"},{"name":"Schroders plc"},{"name":"Standard Life plc"},{"name":"SSE plc"},{"name":"Standard Chartered PLC"},{"name":"Tesco PLC"},{"name":"Whitbread PLC"}],"edges":[{"source":0,"target":29,"officers":["MEDORI, Rene"]},{"source":0,"target":30,"officers":["GROTE, Byron Elmer"]},{"source":0,"target":31,"officers":["GROTE, Byron Elmer"]},{"source":1,"target":13,"officers":["BASON, John George"]}]}; 

Answer 1

。無効なトークンがあり、一部の内部オブジェクトには、{などがありません。

ただし、すべての役員配列をループして最大長を見つけることができます。私はあなたがスケールを作成する方法を知っていればいいと思います。簡単Array.prototype.mapと単一工程で

var lengths = edges.map(function(edge){ 
    return edge.officers.length; 
}); 

console.log(lengths); 
var maxLength = Math.max(...lengths); 

console.log(maxLength); 

Math.maxを使用d3.max

var maxlength = d3.max(edges, function(d) { return d.officers.length; }) 

使用

var edges = [{"source":0,"target":29,"officers":["MEDORI, Rene"]}, 
      {"source":6,"target":28,"officers":["GILLIES, Crawford Scott","GRIMSTONE, Gerald Edgar, Sir"]}, 
      {"source":9,"target":10,"officers":["ANDERSON, Paul Milton"]}, 
      {"source":9,"target":19,"officers":["FREW, Anita Margaret"]}, 
      {"source":9,"target":23,"officers":["BRINDED, Malcolm Arthur"]}, 
      {"source":15,"target":32,"officers":["KENNEDY, Christopher John"]}, 
      {"source":24,"target":31,"officers":["CHAMBERS, Stuart John"]}, 
      {"source":28,"target":29,"officers":["GILLIES, Crawford Scott"]}, 
      "source":30,"target":31,"officers":["GROTE, Byron Elmer"]}]; 

、ES6

maxLength = Math.max(...edges.map(edge=> edge.officers.length));