JSFiddle - React, Tailwind, and code Playground

by Sergey Kalashnikov

JavaScript

var yields = [{yield: 27.00, variety: "Manchuria", year: 1931, site: "University Farm"},
              {yield: 48.87, variety: "Manchuria", year: 1931, site: "Waseca"},
              {yield: 27.43, variety: "Manchuria", year: 1931, site: "Morris"}, ...]


var nest = d3.nest()
    .key(function(d) { return d.year; })
    .key(function(d) { return d.variety; })
    .entries(yields);

console.log(nest)