Update via comments

doc/computation.rst

@@ -231,11 +231,11 @@ the excess entries or padding ``nan`` to insufficient entries,
   da.coarsen(time=30, x=2, boundary='trim').mean()
 
 If you want to apply a specific function to coordinate, you can pass the
-function of function name to ``coordinate_func`` option,
+function of function name to ``coord_func`` option,
 
 .. ipython:: python
 
-  da.coarsen(time=7, x=2, coordinate_func={'time': 'min'}).mean()
+  da.coarsen(time=7, x=2, coord_func={'time': 'min'}).mean()
 
 
 Computation using Coordinates

xarray/core/variable.py

@@ -1696,8 +1696,8 @@ def _coarsen_reshape(self, windows, boundary, side):
                 variable = variable.pad_with_fill_value(pad_widths)
             else:
                 raise TypeError(
-                    '{} is invalid for boundary. Valid option is \'exact\', '
-                    '\'trim\' and \'pad\''.format(boundary[d]))
+                    "{} is invalid for boundary. Valid option is 'exact', "
+                    "'trim' and 'pad'".format(boundary[d]))
 
         shape = []
         axes = []

xarray/tests/test_dataset.py

@@ -4462,7 +4462,6 @@ def test_coarsen_coords(ds, dask):
     # should be no error
     ds.isel(x=slice(0, 3 * (len(ds['x']) // 3))).coarsen(x=3).mean()
 
-    # raise if exact
     # working test with pd.time
     da = xr.DataArray(
         np.linspace(0, 365, num=364), dims='time',

xarray/tests/test_variable.py

@@ -1701,6 +1701,15 @@ def test_coarsen(self):
                 ({'x': 2, 'y': 3}, np.max, 'left', {'x': 'pad', 'y': 'trim'})]:
             v.coarsen(windows, func, boundary, side)
 
+    def test_coarsen_2d(self):
+        v = self.cls(['x', 'y'], np.arange(6 * 12).reshape(6, 12))
+        actual = v.coarsen({'x': 3, 'y': 4}, func='mean')
+        assert actual.shape == (2, 3)
+
+        v = self.cls(['x', 'y'], np.arange(7 * 12).reshape(7, 12))
+        actual = v.coarsen({'x': 3, 'y': 4}, func='mean', boundary='trim')
+        assert actual.shape == (2, 3)
+
 
 @requires_dask
 class TestVariableWithDask(VariableSubclassobjects):
@@ -1855,6 +1864,10 @@ def test_pad(self):
     def test_rolling_window(self):
         super(TestIndexVariable, self).test_rolling_window()
 
+    @pytest.mark.xfail
+    def test_coarsen_2d(self):
+        super(TestIndexVariable, self).test_coarsen_2d()
+
 
 class TestAsCompatibleData(object):
     def test_unchanged_types(self):