在 D3 中读取 CSV 并将其转换为数组数组

Question

我将以下小数据集硬编码到我的代码中的一个变量中：

var dataset = [['CENTRAL', 44, 552, 18565], 
                ['NORTHERN', 42, 945, 20092], 
                ['SOUTHERN', 96, 795, 30095], 
                ['PARK', 1, 640, 9341], 
                ['MISSION', 66, 1198, 18542], 
                ['TENDERLOIN', 23, 113, 10735], 
                ['RICHMOND', 9, 561, 9082], 
                ['TARAVAL', 81, 789, 11966], 
                ['INGLESIDE', 5, 1368, 13414], 
                ['BAYVIEW', 7, 985, 14711]];

现在，这个数据集直接取自一个 .csv 文件，如下所示：

District,Prostitution,VehicleTheft,Totalcrimecount
CENTRAL,44,552,18565
NORTHERN,42,945,20092
SOUTHERN,96,795,30095
PARK,1,640,9341
MISSION,66,1198,18542
TENDERLOIN,23,113,10735
RICHMOND,9,561,9082
TARAVAL,81,789,11966
INGLESIDE,5,1368,13414
BAYVIEW,7,985,14711

但是，我显然希望能够只读取文件，我曾尝试使用此文件：

var dataset_csv = d3.csv("datafile.csv", function(d){
    console.log(dataset_csv = d)
}); 

这给了我一个看起来像这样的对象数组：

[Object, Object, Object, Object, Object, Object, Object, Object, Object, Object]

District: "CENTRAL"
Prostitution: "44"
Totalcrimecount: "18565"
VehicleTheft: "552"

我的问题是，这可能是微不足道的，我如何将这些对象转换为像我的初始数据集一样的数组数据结构？我已经和它斗争了一段时间了。任何提示都非常感谢。

Answer 1

使用Array#map 迭代每个对象，使用Object.keys 仅捕获键值。

var dataset_csv = [{District: "CENTRAL", Prostitution: "44", Totalcrimecount: "18565", VehicleTheft: "552"}, {District: "WEST", Prostitution: "22", Totalcrimecount: "4324", VehicleTheft: "53"}, {District: "EAST", Prostitution: "11", Totalcrimecount: "23434" , VehicleTheft: "76"}],
    datasetArr = dataset_csv.map(v => Object.keys(v).map(c => Number(v[c]) ? Number(v[c]) : v[c]));
    
    console.log(datasetArr);