From 526255ff0ff20280dd0723ddf5e649a05afbe51a Mon Sep 17 00:00:00 2001
From: Santiago Soler <santiago.r.soler@gmail.com>
Date: Sat, 6 Nov 2021 12:29:43 -0300
Subject: [PATCH] Pad with zeros by default

---
 xrft/padding.py            |  8 ++++----
 xrft/tests/test_padding.py | 18 ++++++++----------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/xrft/padding.py b/xrft/padding.py
index cd2df763..c4b4937b 100644
--- a/xrft/padding.py
+++ b/xrft/padding.py
@@ -12,7 +12,7 @@ def pad(
     pad_width=None,
     mode="constant",
     stat_length=None,
-    constant_values=None,
+    constant_values=0,
     end_values=None,
     reflect_type=None,
     **pad_width_kwargs,
@@ -107,7 +107,7 @@ def pad(
     ...     coords={"x": [0, 1, 2], "y": [-5, -4, -3]},
     ...     dims=("y", "x"),
     ... )
-    >>> da_padded = pad(da, x=2, y=1, constant_values=0)
+    >>> da_padded = pad(da, x=2, y=1)
     >>> da_padded
     <xarray.DataArray (y: 5, x: 7)>
     array([[0, 0, 0, 0, 0, 0, 0],
@@ -135,7 +135,7 @@ def pad(
 
     Asymmetric padding
 
-    >>> da_padded = pad(da, x=(1, 4), constant_values=0)
+    >>> da_padded = pad(da, x=(1, 4))
     >>> da_padded
     <xarray.DataArray (y: 3, x: 8)>
     array([[0, 1, 2, 3, 0, 0, 0, 0],
@@ -317,7 +317,7 @@ def unpad(da, pad_width=None, **pad_width_kwargs):
     ...     coords={"x": [0, 1, 2], "y": [-5, -4, -3]},
     ...     dims=("y", "x"),
     ... )
-    >>> da_padded = pad(da, x=2, y=1, constant_values=0)
+    >>> da_padded = pad(da, x=2, y=1)
     >>> da_padded
     <xarray.DataArray (y: 5, x: 7)>
     array([[0, 0, 0, 0, 0, 0, 0],
diff --git a/xrft/tests/test_padding.py b/xrft/tests/test_padding.py
index 334fc5fa..3a279fae 100644
--- a/xrft/tests/test_padding.py
+++ b/xrft/tests/test_padding.py
@@ -69,13 +69,12 @@ def test_pad_with_kwargs(sample_da_2d):
     """
     Test pad function by passing pad_width as kwargs
     """
-    # Check if the array is padded with nans by default
     padded_da = pad(sample_da_2d, x=2, y=1)
     assert padded_da.shape == (19, 15)
-    npt.assert_allclose(padded_da.values[:1, :], np.nan)
-    npt.assert_allclose(padded_da.values[-1:, :], np.nan)
-    npt.assert_allclose(padded_da.values[:, :2], np.nan)
-    npt.assert_allclose(padded_da.values[:, -2:], np.nan)
+    npt.assert_allclose(padded_da.values[:1, :], 0)
+    npt.assert_allclose(padded_da.values[-1:, :], 0)
+    npt.assert_allclose(padded_da.values[:, :2], 0)
+    npt.assert_allclose(padded_da.values[:, -2:], 0)
     npt.assert_allclose(padded_da.values[1:-1, 2:-2], sample_da_2d)
     npt.assert_allclose(padded_da.x, np.linspace(-2, 12, 15))
     npt.assert_allclose(padded_da.y, np.linspace(-4.5, 4.5, 19))
@@ -85,14 +84,13 @@ def test_pad_with_pad_width(sample_da_2d):
     """
     Test pad function by passing pad_width as argument
     """
-    # Check if the array is padded with nans by default
     pad_width = {"x": (2, 3), "y": (1, 3)}
     padded_da = pad(sample_da_2d, pad_width)
     assert padded_da.shape == (21, 16)
-    npt.assert_allclose(padded_da.values[:1, :], np.nan)
-    npt.assert_allclose(padded_da.values[-3:, :], np.nan)
-    npt.assert_allclose(padded_da.values[:, :2], np.nan)
-    npt.assert_allclose(padded_da.values[:, -3:], np.nan)
+    npt.assert_allclose(padded_da.values[:1, :], 0)
+    npt.assert_allclose(padded_da.values[-3:, :], 0)
+    npt.assert_allclose(padded_da.values[:, :2], 0)
+    npt.assert_allclose(padded_da.values[:, -3:], 0)
     npt.assert_allclose(padded_da.values[1:-3, 2:-3], sample_da_2d)
     npt.assert_allclose(padded_da.x, np.linspace(-2, 13, 16))
     npt.assert_allclose(padded_da.y, np.linspace(-4.5, 5.5, 21))