call np.cross with 3D vectors only (#8993)

* convert the expected parameters to arrays

* manually zero-pad to avoid calling `np.cross` with 2D vectors

Author: keewis

xarray/tests/test_computation.py

@@ -2500,32 +2500,32 @@ def test_polyfit_polyval_integration(
         [
             xr.DataArray([1, 2, 3]),
             xr.DataArray([4, 5, 6]),
-            [1, 2, 3],
-            [4, 5, 6],
+            np.array([1, 2, 3]),
+            np.array([4, 5, 6]),
             "dim_0",
             -1,
         ],
         [
             xr.DataArray([1, 2]),
             xr.DataArray([4, 5, 6]),
-            [1, 2],
-            [4, 5, 6],
+            np.array([1, 2, 0]),
+            np.array([4, 5, 6]),
             "dim_0",
             -1,
         ],
         [
             xr.Variable(dims=["dim_0"], data=[1, 2, 3]),
             xr.Variable(dims=["dim_0"], data=[4, 5, 6]),
-            [1, 2, 3],
-            [4, 5, 6],
+            np.array([1, 2, 3]),
+            np.array([4, 5, 6]),
             "dim_0",
             -1,
         ],
         [
             xr.Variable(dims=["dim_0"], data=[1, 2]),
             xr.Variable(dims=["dim_0"], data=[4, 5, 6]),
-            [1, 2],
-            [4, 5, 6],
+            np.array([1, 2, 0]),
+            np.array([4, 5, 6]),
             "dim_0",
             -1,
         ],
@@ -2564,8 +2564,8 @@ def test_polyfit_polyval_integration(
                 dims=["cartesian"],
                 coords=dict(cartesian=(["cartesian"], ["x", "y", "z"])),
             ),
-            [0, 0, 1],
-            [4, 5, 6],
+            np.array([0, 0, 1]),
+            np.array([4, 5, 6]),
             "cartesian",
             -1,
         ],
@@ -2580,8 +2580,8 @@ def test_polyfit_polyval_integration(
                 dims=["cartesian"],
                 coords=dict(cartesian=(["cartesian"], ["x", "y", "z"])),
             ),
-            [1, 0, 2],
-            [4, 5, 6],
+            np.array([1, 0, 2]),
+            np.array([4, 5, 6]),
             "cartesian",
             -1,
         ],