diff --git a/basictypes.py b/basictypes.py
index 4d3055c..ae36187 100644
--- a/basictypes.py
+++ b/basictypes.py
@@ -74,11 +74,15 @@ class Line:
 class WallIDMismatch (RuntimeError): ...
 
 # Helper methods
-def polar_to_cart(self, r, theta_deg) -> tuple:
+def polar_to_cart(r, theta_deg) -> tuple:
     #print('polar to cart ',r, theta_deg)
     x = r * math.cos(deg_to_rad(theta_deg))
     y = r * math.sin(deg_to_rad(theta_deg))
     return x,y
 
 def deg_to_rad(theta_deg) -> float:
-    return theta_deg*(math.pi/180)
\ No newline at end of file
+    return theta_deg*(math.pi/180)
+
+def point_from_polar(r, theta, wall_id) -> PointWithID:
+    x, y = polar_to_cart(r, theta)
+    return PointWithID(x, y, wall_id)