1 files changed, 6 insertions, 0 deletions
diff --git a/transform.py b/transform.py
index 4e5eb9c..cab23fb 100644
--- a/transform.py
+++ b/transform.py
@@ -1,6 +1,12 @@
 import numpy as np
 
 def rotate(x, phi, n):
+    """
+    Rotate an array of points `x` through an angle phi counter-clockwise
+    around the axis `n` (when looking towards +infinity).
+
+    Source: Weisstein, Eric W. "Rotation Formula." Mathworld.
+    """
     x = np.asarray(x)
     n = np.asarray(n)