initial commit

tests/test_geo.py

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+import unittest
+
+import numpy as np
+
+from surveyladder.geo import chainage_to_xy, chainage_offset_to_xy, poly_area, poly_centroid, trilaterate_xy
+
+
+class TestPolyArea(unittest.TestCase):
+
+    def test_poly_area(self):
+        polygon = np.array([[0, 0], [4, 0], [4, 3]])
+        self.assertEqual(poly_area(polygon), 6)
+
+
+class TestTrilaterateXY(unittest.TestCase):
+
+    def test_trilaterate_xy_on_line(self):
+        A = np.array([0, 0])
+        B = np.array([10, 0])
+        a = 5
+        b = 5
+        C = trilaterate_xy(A, a, B, b)
+        np.testing.assert_almost_equal(C, [5, 0])
+
+    def test_trilaterate_xy_right_triangle(self):
+        A = np.array([0, 0])
+        B = np.array([4, 0])
+        a = 5
+        b = 3
+        C = trilaterate_xy(A, a, B, b)
+        np.testing.assert_almost_equal(C, [4, 3])
+
+    def test_trilaterate_xy_right_triangle_swapped(self):
+        A = np.array([4, 0])
+        B = np.array([0, 0])
+        a = 3
+        b = 5
+        C = trilaterate_xy(A, a, B, b)
+        np.testing.assert_almost_equal(C, [4, -3])
+
+
+class TestChainageToXY(unittest.TestCase):
+
+    def test_positive_distance(self):
+        np.testing.assert_almost_equal(
+            chainage_to_xy(np.array([3, 5]), np.array([6, 9]), 10),
+            [9, 13])
+
+    def test_negative_distance(self):
+        np.testing.assert_almost_equal(
+            chainage_to_xy(np.array([3, 5]), np.array([6, 9]), -5),
+            [0, 1])
+
+
+class TestChainageOffsetToXY(unittest.TestCase):
+
+    def test_positive_offset(self):
+        A = np.array([0, 0])
+        B = np.array([0, 1])
+        a_distance = 5
+        perp_distance = 2
+        P = chainage_offset_to_xy(A, B, a_distance, perp_distance)
+        np.testing.assert_almost_equal(P, [-2, 5])
+
+class TestPolyCentroid(unittest.TestCase):
+
+    def test_pos_square(self):
+        # mathematically positive point ordering
+        poly = np.array([[0,0], [1,0], [1,2], [0,2]])
+        np.testing.assert_almost_equal(poly_centroid(poly), [0.5, 1])
+
+    def test_neg_square(self):
+        # mathematically negative point ordering
+        poly = np.array([[0,0], [1,0], [1,-2], [0,-2]])
+        np.testing.assert_almost_equal(poly_centroid(poly), [0.5, -1])
+
+
+unittest.main()