From 6697efd6278d4049b83553aa7db24c9abe35e3f3 Mon Sep 17 00:00:00 2001
From: Taylor Bockman <tbockman@xchg.sh>
Date: Tue, 3 Sep 2019 18:20:04 -0700
Subject: [PATCH] Add euclidean distance and tests

---
 clusterview/math.py | 23 +++++++++++++++++++++++
 tests/test_math.py  | 19 +++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 clusterview/math.py
 create mode 100644 tests/test_math.py

diff --git a/clusterview/math.py b/clusterview/math.py
new file mode 100644
index 0000000..bf8c6eb
--- /dev/null
+++ b/clusterview/math.py
@@ -0,0 +1,23 @@
+import math
+
+from .points import Point
+
+
+class Math:
+    """
+    Defines useful static helper methods for mathematical functions in
+    Computational Geometry.
+    """
+
+    @classmethod
+    def euclidean_distance(cls, p1, p2):
+        """
+        Given two points of type Point, returns the euclidean distance between
+        those two points.
+        """
+
+        if not isinstance(p1, Point) or not isinstance(p2, Point):
+            raise ValueError("Euclidean distance can only be calculated " +
+                             "on points")
+
+        return math.sqrt(math.pow(p2.x - p1.x, 2) + math.pow(p2.y - p1.y, 2))
diff --git a/tests/test_math.py b/tests/test_math.py
new file mode 100644
index 0000000..04e3198
--- /dev/null
+++ b/tests/test_math.py
@@ -0,0 +1,19 @@
+import pytest
+
+from clusterview.colors import Color
+from clusterview.math import Math
+from clusterview.points import Point
+
+
+def test_euclidean_distance():
+    p1 = Point(150, 100, Color.BLACK, 8, 800, 600)
+    p2 = Point(300, 200, Color.BLACK, 8, 800, 600)
+
+    d = Math.euclidean_distance(p1, p2)
+
+    assert round(d, 2) == 180.28
+
+
+def test_euclidean_distance_bad_points():
+    with pytest.raises(ValueError):
+        Math.euclidean_distance(1, 1)