From 0bb4d68487c80701a99e6f1e6bb56dbf412dc894 Mon Sep 17 00:00:00 2001
From: John Lambert <johnwl@stanford.edu>
Date: Wed, 3 Mar 2021 00:44:07 -0500
Subject: [PATCH] add a unit test for line case

---
 python/gtsam/tests/test_Sim3.py | 52 +++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 python/gtsam/tests/test_Sim3.py

diff --git a/python/gtsam/tests/test_Sim3.py b/python/gtsam/tests/test_Sim3.py
new file mode 100644
index 000000000..3f4329eb4
--- /dev/null
+++ b/python/gtsam/tests/test_Sim3.py
@@ -0,0 +1,52 @@
+"""
+GTSAM Copyright 2010-2019, Georgia Tech Research Corporation,
+Atlanta, Georgia 30332-0415
+All Rights Reserved
+
+See LICENSE for the license information
+
+Sim3 unit tests.
+Author: John Lambert
+"""
+# pylint: disable=no-name-in-module
+import math
+import unittest
+
+import numpy as np
+
+import gtsam
+from gtsam import Point3, Pose3, Pose3Pairs, Rot3, Similarity3
+from gtsam.utils.test_case import GtsamTestCase
+
+
+class TestSim3(GtsamTestCase):
+    """Test selected Sim3 methods."""
+
+    def test_align_poses_along_straight_line(self):
+        """Test Align Pose3Pairs method."""
+
+        Rx90 = Rot3.Rx(np.deg2rad(90))
+
+        w1Ti0 = Pose3(Rot3(), np.array([5, 0, 0]))
+        w1Ti1 = Pose3(Rot3(), np.array([10, 0, 0]))
+        w1Ti2 = Pose3(Rot3(), np.array([15, 0, 0]))
+
+        w1Ti_list = [w1Ti0, w1Ti1, w1Ti2]
+
+        w2Ti0 = Pose3(Rx90, np.array([-10, 0, 0]))
+        w2Ti1 = Pose3(Rx90, np.array([-5, 0, 0]))
+        w2Ti2 = Pose3(Rx90, np.array([0, 0, 0]))
+
+        w2Ti_list = [w2Ti0, w2Ti1, w2Ti2]
+
+        pairs = list(zip(w2Ti_list, w1Ti_list))
+        pose_pairs = Pose3Pairs(pairs)
+
+        w2Sw1 = Similarity3.Align(pose_pairs)
+
+        for w1Ti, w2Ti in zip(w1Ti_list, w2Ti_list):
+            self.gtsamAssertEquals(w2Ti, w2Sw1.transformFrom(w1Ti))
+
+
+if __name__ == "__main__":
+    unittest.main()