Method groupIn

src/api/data-array.ts:88–88

* If the array is not grouped, groups it as `groupBy` does; otherwise, groups the elements inside each current * group. This allows for top-down recursive grouping which may be easier than bottom-up grouping.

(key: ArrayFunc<LowestKey<T>, U>, comparator?: ArrayComparator<U>)

     * group. This allows for top-down recursive grouping which may be easier than bottom-up grouping.
     */
    groupIn<U>(key: ArrayFunc<LowestKey<T>, U>, comparator?: ArrayComparator<U>): DataArray<Ingrouped<U, T>>;

    /**
     * Return distinct entries. If a key is provided, then rows with distinct keys are returned.