From 9a1cfd433fc5274fe07ebe33d7b8e409e3297ee6 Mon Sep 17 00:00:00 2001
From: Anson <anson@ansonbiggs.com>
Date: Wed, 20 Jan 2021 21:31:12 -0700
Subject: [PATCH] added quaternion from ypr

---
 src/Quaternions.jl |  7 ++++---
 test/runtests.jl   | 15 ++++++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/Quaternions.jl b/src/Quaternions.jl
index 5fb7efd..5641819 100644
--- a/src/Quaternions.jl
+++ b/src/Quaternions.jl
@@ -8,7 +8,8 @@ struct Quaternion
 	Quaternion(q) = Quaternion(q[1], q[2], q[3], q[4]) 
 	Quaternion() = new(0, 0, 0, 1)
 	
-	# Quaternion(ē, ϕ) = Quaternion(vcat(if sum(ē) == 0 ? [0 0 0] : ē / norm(ē) * sin(ϕ / 2),cos(ϕ / 2)))
+	Quaternion(yaw, pitch, roll) = Quaternion([0 0 sin(yaw / 2) cos(yaw / 2)]) * Quaternion([0 sin(pitch / 2) 0 cos(pitch / 2)]) * Quaternion([sin(roll / 2) 0 0 cos(roll / 2)])
+	
 	function Quaternion(ē, ϕ)
 		if sum(ē) == 0
 			return Quaternion([0 0 0 cos(ϕ / 2)])
@@ -40,6 +41,6 @@ Base.isapprox(a::Quaternion,b::Quaternion) = isapprox(collect(a), collect(b))
 
 LinearAlgebra.norm(q::Quaternion) = norm(collect(q))
 LinearAlgebra.normalize(q::Quaternion) = collect(q) / norm(q)
-# q = Quaternion([1,-2,2], -2 * pi / 3) * Quaternion([0,0,0,1])
 
-# println(q[3])
\ No newline at end of file
+
+export Quaternion
diff --git a/test/runtests.jl b/test/runtests.jl
index b86de1d..7a162f4 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,12 +1,21 @@
 using AstroHelper
 using Test
 
-import AstroHelper: Quaternion
+import AstroHelper
 
 @testset "Quaternion Initialization" begin
     @test Quaternion().r == 1.0
-    @test Quaternion([0,0,0,1]) == Quaternion(0, 0, 0, 1)
-    @test Quaternion([0 0 0], 0) == Quaternion(0, 0, 0, 1)
+    @test Quaternion([0,0,0,1]) == Quaternion()
+    @test Quaternion([0 0 0], 0) == Quaternion()
     @test Quaternion([1 -2 2], (-2 * pi / 3)) ≈ Quaternion([-sqrt(3) / 6, sqrt(3) / 3, -sqrt(3) / 3, 1 / 2])
+
+    # Roll of pi/2
+    @test Quaternion(0, 0, pi / 2) ≈ Quaternion([1 0 0], pi / 2)
+    
     @test_throws ErrorException Quaternion(1, 2, 3, 4)
+end
+
+@testset "Quaternion Math" begin
+    # Quaternion Multiplication is not Communitive.
+    # @test Quaternion() * Quaternion([0 1 0 0]) != Quaternion([0 1 0 0]) * Quaternion()
 end
\ No newline at end of file