From 65381f3744bd00a76dbec0933971e16a37cfef21 Mon Sep 17 00:00:00 2001
From: keisuke fujii <fujiisoup@gmail.com>
Date: Sun, 9 Aug 2020 08:32:53 +0900
Subject: [PATCH 1/4] ndrolling repr fix

---
 xarray/core/rolling.py         | 4 ++--
 xarray/tests/test_dataarray.py | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/xarray/core/rolling.py b/xarray/core/rolling.py
index 5f996565243..62d14fadc01 100644
--- a/xarray/core/rolling.py
+++ b/xarray/core/rolling.py
@@ -99,8 +99,8 @@ def __repr__(self):
         """provide a nice str repr of our rolling object"""
 
         attrs = [
-            "{k}->{v}".format(k=k, v=getattr(self, k))
-            for k in list(self.dim) + self.window + self.center + [self.min_periods]
+            "{k}->{v}{c}".format(k=k, v=w, c="(center)" if c else "")
+            for k, w, c in zip(self.dim, self.window, self.center)
         ]
         return "{klass} [{attrs}]".format(
             klass=self.__class__.__name__, attrs=",".join(attrs)
diff --git a/xarray/tests/test_dataarray.py b/xarray/tests/test_dataarray.py
index 7ccf1eb14bc..7bd2fcf1e0b 100644
--- a/xarray/tests/test_dataarray.py
+++ b/xarray/tests/test_dataarray.py
@@ -6178,6 +6178,8 @@ def test_rolling_iter(da):
                 actual.values[actual.values.nonzero()],
                 expected.values[expected.values.nonzero()],
             )
+    # no error
+    repr(rolling_obj)
 
 
 def test_rolling_doc(da):

From 7e1fbf87b898851d26de3eb3ab328637d61437bc Mon Sep 17 00:00:00 2001
From: keisuke fujii <fujiisoup@gmail.com>
Date: Sun, 9 Aug 2020 08:48:03 +0900
Subject: [PATCH 2/4] better tests

---
 xarray/tests/test_dataarray.py | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/xarray/tests/test_dataarray.py b/xarray/tests/test_dataarray.py
index 7bd2fcf1e0b..75b0b4847b3 100644
--- a/xarray/tests/test_dataarray.py
+++ b/xarray/tests/test_dataarray.py
@@ -6178,8 +6178,16 @@ def test_rolling_iter(da):
                 actual.values[actual.values.nonzero()],
                 expected.values[expected.values.nonzero()],
             )
-    # no error
-    repr(rolling_obj)
+
+
+@pytest.mark.parametrize("da", (1,), indirect=True)
+def test_rolling_repr(da):
+    rolling_obj = da.rolling(time=7)
+    assert repr(rolling_obj) == "DataArrayRolling [time->7]"
+    rolling_obj = da.rolling(time=7, center=True)
+    assert repr(rolling_obj) == "DataArrayRolling [time->7(center)]"
+    rolling_obj = da.rolling(time=7, x=3, center=True)
+    assert repr(rolling_obj) == "DataArrayRolling [time->7(center),x->3(center)]"
 
 
 def test_rolling_doc(da):

From 61c9ff9d4bbbe53c03c6b467e1dafabc3660144e Mon Sep 17 00:00:00 2001
From: keisuke fujii <fujiisoup@gmail.com>
Date: Sun, 9 Aug 2020 19:49:12 +0900
Subject: [PATCH 3/4] correct doc and error message.

---
 doc/computation.rst    | 4 ++--
 xarray/core/rolling.py | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/doc/computation.rst b/doc/computation.rst
index 474c3905981..b096099385e 100644
--- a/doc/computation.rst
+++ b/doc/computation.rst
@@ -234,7 +234,7 @@ windowed rolling, convolution, short-time FFT etc.
 .. ipython:: python
 
     # rolling with 2-point stride
-    rolling_da = r.construct("window_dim", stride=2)
+    rolling_da = r.construct(x="x_win", y="y_win", stride=2)
     rolling_da
     rolling_da.mean("window_dim", skipna=False)
 
@@ -245,7 +245,7 @@ You can also use ``construct`` to compute a weighted rolling sum:
 .. ipython:: python
 
     weight = xr.DataArray([0.25, 0.5, 0.25], dims=["window"])
-    arr.rolling(y=3).construct("window").dot(weight)
+    arr.rolling(y=3).construct(y="window").dot(weight)
 
 .. note::
   numpy's Nan-aggregation functions such as ``nansum`` copy the original array.
diff --git a/xarray/core/rolling.py b/xarray/core/rolling.py
index 62d14fadc01..fb38c0c7fe6 100644
--- a/xarray/core/rolling.py
+++ b/xarray/core/rolling.py
@@ -156,7 +156,9 @@ def _mapping_to_list(
         elif len(self.dim) == 1:
             return [arg]
         else:
-            raise ValueError("Mapping argument is necessary.")
+            raise ValueError(
+                "Mapping argument is necessary for {}d-rolling.".format(len(self.dim))
+            )
 
 
 class DataArrayRolling(Rolling):

From 3b9cf9819679a9080a26ba469b78563981a3a9d1 Mon Sep 17 00:00:00 2001
From: keisuke fujii <fujiisoup@gmail.com>
Date: Sun, 9 Aug 2020 20:26:06 +0900
Subject: [PATCH 4/4] also update the mean dimensions.

---
 doc/computation.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/computation.rst b/doc/computation.rst
index b096099385e..dcfe270a942 100644
--- a/doc/computation.rst
+++ b/doc/computation.rst
@@ -236,7 +236,7 @@ windowed rolling, convolution, short-time FFT etc.
     # rolling with 2-point stride
     rolling_da = r.construct(x="x_win", y="y_win", stride=2)
     rolling_da
-    rolling_da.mean("window_dim", skipna=False)
+    rolling_da.mean(["x_win", "y_win"], skipna=False)
 
 Because the ``DataArray`` given by ``r.construct('window_dim')`` is a view
 of the original array, it is memory efficient.