Visualization toolmaker. Founder @observablehq. Creator @d3. Former @nytgraphics. Pronounced BOSS-tock.
data = [
{name: "jim", amount: "34.0", date: "11/12/2015"},
{name: "carl", amount: "120.11", date: "11/12/2015"},
{name: "stacy", amount: "12.01", date: "01/04/2016"},
{name: "stacy", amount: "34.05", date: "01/04/2016"}
]
new Map(Array.from(
group(data, d => d.name),
([name, data]) => [name, group(data, d => d.date)]
))
function nest(values, ...keys) {
return (function regroup(values, i) {
if (i >= keys.length) return values;
const map = group(values, keys[i]);
return new Map(Array.from(map, ([k, v]) => [k, regroup(v, i + 1)]));
})(values, 0);
}
nest(data, d => d.name, d => d.date)
nest(data, d => d.name)
nest(data)
function rollup(values, reduce, ...keys) {
return (function regroup(values, i) {
if (i >= keys.length) return reduce(values);
const map = group(values, keys[i]);
return new Map(Array.from(map, ([k, v]) => [k, regroup(v, i + 1)]));
})(values, 0);
}
rollup(data, v => v.length, d => d.name, d => d.date)
rollup(data, v => v.length, d => d.name)
rollup(data, v => v.length)
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