@@ -40,9 +40,9 @@ New features
4040^^^^^^^^^^^
4141
4242Series & DataFrame have been enhanced to support the aggregation API. This is an already familiar API that
43- is supported for groupby, windows operations, and resampling. This allows one to express, possibly multiple
44- aggregation operations in a single concise way by using `` .agg()`` and ``.transform()``. The
45- full documentation is :ref:`here <basics.aggregate>`` (:issue:`1623`)
43+ is supported for groupby, window operations, and resampling. This allows one to express, possibly multiple
44+ aggregation operations, in a single concise way by using :meth:`~DataFrame .agg`,
45+ and :meth:`~DataFrame.transform`. The full documentation is :ref:`here <basics.aggregate>`` (:issue:`1623`)
4646
4747Here is a sample
4848
@@ -67,28 +67,22 @@ Multiple functions in lists.
6767
6868 df.agg(['sum', 'min'])
6969
70- Dictionaries to provide the ability to selective calculation.
70+ Dictionaries to provide the ability to provide selective aggregation per column.
71+ You will get a matrix-like output of all of the aggregators. The output will consist
72+ of all unique functions. Those that are not noted for a particular column will be ``NaN``:
7173
7274.. ipython:: python
7375
7476 df.agg({'A' : ['sum', 'min'], 'B' : ['min', 'max']})
7577
76- When operating on a Series, passing a dictionry allows one to rename multiple
77- function aggregates; this will return a MultiIndexed Series. The outer level
78- are the keys, the inner are the names of the functions.
79-
80- .. ipython:: python
81-
82- df.A.agg({'foo':['sum', 'min'], 'bar' : ['count','max']})
83-
8478The API also supports a ``.transform()`` function to provide for broadcasting results.
8579
8680.. ipython:: python
8781
88- df.transform(['abs', lambda x: x- x.min()])
82+ df.transform(['abs', lambda x: x - x.min()])
8983
90- When presented with mixed dtypes that cannot aggregate, ``.agg`` will only take the valid
91- aggregations. This is similiar to how groupby ``.agg`` works. (:issue:`15015`)
84+ When presented with mixed dtypes that cannot aggregate, ``.agg() `` will only take the valid
85+ aggregations. This is similiar to how groupby ``.agg() `` works. (:issue:`15015`)
9286
9387.. ipython:: python
9488
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