mlitAreas = {
let wards = Object.keys(tokyoAreasByWard);
let index = {};
for (let ward of wards) {
let sales = mlitSales.filter((s) => s["市区町村名"] == ward);
let uniqueAreas = new Set();
sales.map((s) => s["地区名"]).forEach((a) => uniqueAreas.add(a));
let areas = {};
for (let area of uniqueAreas) {
areas[area] = sales.filter((s) => s["地区名"] == area);
}
index[ward] = areas;
}
return index;
}