Add test for multidimensional use of rotate_vector.

src/solarspatialtools/spatial.py

@@ -312,7 +312,9 @@ def rotate_vector(vector, theta):
     Parameters
     ----------
     vector : (x, y) numeric
-        A tuple (or numpy array) containing the input vector
+        A tuple (or numpy array) containing the input vector.
+        To operate on multiple points, vector should be of the form:
+            ((x1, x2, x3, x4), (y1, y2, y3, y4))
 
     theta : numeric
         Angle of rotation in radians
@@ -321,7 +323,8 @@ def rotate_vector(vector, theta):
     -------
     (x, y) : numeric
         A tuple (or numpy array) containing the rotated vector. Matches data
-        type of input.
+        type of input. If input an array of x's and y's, output will be
+        oriented ((x1', x2', x3', x4'), (y1', y2', y3', y4'))
     """
 
     rot_matrix = np.array([[np.cos(theta), -np.sin(theta)],

tests/test_spatial.py

@@ -399,6 +399,11 @@ def test_rotate_vector_numpy():
     assert r1 == approx([0, np.sqrt(2)])
 
 
+def test_rotate_vector_multiple():
+    r1 = spatial.rotate_vector(np.array([[1, 0, 1], [0, 1, 1]]), np.deg2rad(90))
+    assert r1 == approx(np.array([[0, -1, -1], [1, 0, 1]]))
+
+
 def test_project_points(projected_dxdy, projected_dists):
     vecs = projected_dists.keys()
     for vec in vecs: