Aggregates an ordered series using the method specified by `Aggregation<K>` and then applies the provided `observationSelector` on each window or chunk to produce the result which is returned as a new series. The selector returns both the key and the value. ## Parameters - `aggregation` - Specifies the aggregation method using `Aggregation<K>`. This is a discriminated union listing various chunking and windowing conditions. - `observationSelector` - A function that is called on each chunk to obtain a key and a value. [category:Windowing, chunking and grouping]

Aggregates an ordered series using the method specified by `Aggregation<K>` and then applies the provided `valueSelector` on each window or chunk to produce the result which is returned as a new series. A key for each window or chunk is selected using the specified `keySelector`. ## Parameters - `aggregation` - Specifies the aggregation method using `Aggregation<K>`. This is a discriminated union listing various chunking and windowing conditions. - `keySelector` - A function that is called on each chunk to obtain a key. - `valueSelector` - A value selector function that is called to aggregate each chunk or window. [category:Windowing, chunking and grouping]