From 70b27a0f6f28ac208930e5c4f9f3e07329d78475 Mon Sep 17 00:00:00 2001
From: Joseph Ryan <josephryan3.14@gmail.com>
Date: Mon, 16 Jul 2018 21:18:38 -0500
Subject: [PATCH] Add unit tests for atan2

---
 src/math/atan2.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/math/atan2.rs b/src/math/atan2.rs
index 324b1e9..1816bca 100644
--- a/src/math/atan2.rs
+++ b/src/math/atan2.rs
@@ -70,3 +70,14 @@ pub fn atan2(y: f64, x: f64) -> f64 {
         _ => (z - PI_LO) - PI, /* atan(-,-) */
     }
 }
+
+#[test]
+fn sanity_check() {
+    assert_eq!(atan2(0.0, 1.0), 0.0);
+    assert_eq!(atan2(0.0, -1.0), PI);
+    assert_eq!(atan2(-0.0, -1.0), -PI);
+    assert_eq!(atan2(3.0, 2.0), atan(3.0/2.0));
+    assert_eq!(atan2(2.0, -1.0), atan(2.0/-1.0) + PI);
+    assert_eq!(atan2(-2.0, -1.0), atan(-2.0/-1.0) - PI);
+}
+