From d8666ad801bae8fe01e48708189ec7ca7174e949 Mon Sep 17 00:00:00 2001
From: Fabian Gans <fgans@bgc-jena.mpg.de>
Date: Tue, 23 Mar 2021 09:24:45 +0100
Subject: [PATCH 1/3] Add more scipy interpolations methods

---
 xarray/core/missing.py       |  3 +++
 xarray/tests/test_missing.py | 12 +++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/xarray/core/missing.py b/xarray/core/missing.py
index e6dd8b537a0..d20ba6855dd 100644
--- a/xarray/core/missing.py
+++ b/xarray/core/missing.py
@@ -460,6 +460,9 @@ def _get_interpolator(method, vectorizeable_only=False, **kwargs):
         "quadratic",
         "cubic",
         "polynomial",
+        "nearest-up",
+        "previous",
+        "next",
     ]
     valid_methods = interp1d_methods + [
         "barycentric",
diff --git a/xarray/tests/test_missing.py b/xarray/tests/test_missing.py
index 2ab3508b667..fd3896d9ae8 100644
--- a/xarray/tests/test_missing.py
+++ b/xarray/tests/test_missing.py
@@ -92,7 +92,17 @@ def make_interpolate_example_data(shape, frac_nan, seed=12345, non_uniform=False
 def test_interpolate_pd_compat():
     shapes = [(8, 8), (1, 20), (20, 1), (100, 100)]
     frac_nans = [0, 0.5, 1]
-    methods = ["linear", "nearest", "zero", "slinear", "quadratic", "cubic"]
+    methods = [
+        "linear",
+        "nearest",
+        "nearest-up",
+        "zero",
+        "slinear",
+        "quadratic",
+        "cubic",
+        "next",
+        "previous",
+    ]
 
     for (shape, frac_nan, method) in itertools.product(shapes, frac_nans, methods):
 

From a68de97cf9bfb406f8c6c51ab2ff57e304d0583b Mon Sep 17 00:00:00 2001
From: Fabian Gans <fgans@bgc-jena.mpg.de>
Date: Tue, 23 Mar 2021 10:36:02 +0100
Subject: [PATCH 2/3] comment out pandas test for now

---
 xarray/core/missing.py       |  4 ++--
 xarray/tests/test_missing.py | 18 ++++++++++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/xarray/core/missing.py b/xarray/core/missing.py
index d20ba6855dd..9788040c239 100644
--- a/xarray/core/missing.py
+++ b/xarray/core/missing.py
@@ -598,8 +598,8 @@ def interp(var, indexes_coords, method, **kwargs):
         Original coordinates should be sorted in strictly ascending order.
         Note that all the coordinates should be Variable objects.
     method : string
-        One of {'linear', 'nearest', 'zero', 'slinear', 'quadratic',
-        'cubic'}. For multidimensional interpolation, only
+        One of {'linear', 'nearest', 'nearest-up', 'zero', 'slinear', 'quadratic',
+        'cubic', 'previous', 'next'}. For multidimensional interpolation, only
         {'linear', 'nearest'} can be used.
     **kwargs
         keyword arguments to be passed to scipy.interpolate
diff --git a/xarray/tests/test_missing.py b/xarray/tests/test_missing.py
index fd3896d9ae8..4eade6cdbf8 100644
--- a/xarray/tests/test_missing.py
+++ b/xarray/tests/test_missing.py
@@ -95,13 +95,13 @@ def test_interpolate_pd_compat():
     methods = [
         "linear",
         "nearest",
-        "nearest-up",
+        # "nearest-up",
         "zero",
         "slinear",
         "quadratic",
         "cubic",
-        "next",
-        "previous",
+        # "next",
+        # "previous",
     ]
 
     for (shape, frac_nan, method) in itertools.product(shapes, frac_nans, methods):
@@ -301,7 +301,17 @@ def test_interpolate_limits():
 
 @requires_scipy
 def test_interpolate_methods():
-    for method in ["linear", "nearest", "zero", "slinear", "quadratic", "cubic"]:
+    for method in [
+        "linear",
+        "nearest",
+        "zero",
+        "slinear",
+        "quadratic",
+        "cubic",
+        "nearest-up",
+        "previous",
+        "next",
+    ]:
         kwargs = {}
         da = xr.DataArray(
             np.array([0, 1, 2, np.nan, np.nan, np.nan, 6, 7, 8], dtype=np.float64),

From 759dfd30aa5f698f628b176d0a5462fbd16c8b30 Mon Sep 17 00:00:00 2001
From: Fabian Gans <fgans@bgc-jena.mpg.de>
Date: Tue, 23 Mar 2021 10:58:52 +0100
Subject: [PATCH 3/3] restrict to next and previous

---
 xarray/core/missing.py       | 3 +--
 xarray/tests/test_missing.py | 2 --
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/xarray/core/missing.py b/xarray/core/missing.py
index 9788040c239..ac0cbe1e702 100644
--- a/xarray/core/missing.py
+++ b/xarray/core/missing.py
@@ -460,7 +460,6 @@ def _get_interpolator(method, vectorizeable_only=False, **kwargs):
         "quadratic",
         "cubic",
         "polynomial",
-        "nearest-up",
         "previous",
         "next",
     ]
@@ -598,7 +597,7 @@ def interp(var, indexes_coords, method, **kwargs):
         Original coordinates should be sorted in strictly ascending order.
         Note that all the coordinates should be Variable objects.
     method : string
-        One of {'linear', 'nearest', 'nearest-up', 'zero', 'slinear', 'quadratic',
+        One of {'linear', 'nearest', 'zero', 'slinear', 'quadratic',
         'cubic', 'previous', 'next'}. For multidimensional interpolation, only
         {'linear', 'nearest'} can be used.
     **kwargs
diff --git a/xarray/tests/test_missing.py b/xarray/tests/test_missing.py
index 4eade6cdbf8..71c1fb0e5ad 100644
--- a/xarray/tests/test_missing.py
+++ b/xarray/tests/test_missing.py
@@ -95,7 +95,6 @@ def test_interpolate_pd_compat():
     methods = [
         "linear",
         "nearest",
-        # "nearest-up",
         "zero",
         "slinear",
         "quadratic",
@@ -308,7 +307,6 @@ def test_interpolate_methods():
         "slinear",
         "quadratic",
         "cubic",
-        "nearest-up",
         "previous",
         "next",
     ]: