Group Elements by several matching attributes

groupBy

function groupBy(array: any[], f): any {
    const groups = {};
    array.forEach(function (o) {
        const group = JSON.stringify(f(o));
        groups[group] = groups[group] || [];
        groups[group].push(o);
    });
    return Object.keys(groups).map(function (group) {
        return groups[group];
    });
}

var result = this.groupBy(coordinates, function (item) {
    return [item.x, item.y];
});