From 4da89e192a757ee06e00bea15c6fe659d424ca32 Mon Sep 17 00:00:00 2001
From: marcandre <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 19 Nov 2014 17:32:58 +0000
Subject: [PATCH] * lib/matrix.rb: Add Vector#angle_with Patch by Egunov
Dmitriy [#10442]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48505 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
ChangeLog | 5 +++++
NEWS | 1 +
lib/matrix.rb | 15 +++++++++++++++
test/matrix/test_vector.rb | 11 +++++++++++
4 files changed, 32 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index b311ff41ab..02fe6b0160 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Nov 20 02:32:34 2014 Marc-Andre Lafortune <ruby-core@marc-andre.ca>
+
+ * lib/matrix.rb: Add Vector#angle_with
+ Patch by Egunov Dmitriy [#10442]
+
Thu Nov 20 02:10:31 2014 Nobuyoshi Nakada <nobu@ruby-lang.org>
* parse.y (ripper_flush_string_content, parser_parse_string):
diff --git a/NEWS b/NEWS
index 8c7d1ea9af..df5b64e961 100644
--- a/NEWS
+++ b/NEWS
@@ -172,6 +172,7 @@ with all sufficient information, see the ChangeLog file.
* Unary - and + added for Vector and Matrix.
* Vector#cross_product generalized to arbitrary dimensions.
* Vector#dot and #cross are aliases for #inner_product and #cross_product.
+ * Vector#angle_with returns the angle with its argument
* Pathname
* Pathname#/ is aliased to Pathname#+.
diff --git a/lib/matrix.rb b/lib/matrix.rb
index f7d75b328f..4d211ddd78 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1699,6 +1699,7 @@ end
# * #-@
#
# Vector functions:
+# * #angle_with(v)
# * #inner_product(v), dot(v)
# * #cross_product(v), cross(v)
# * #collect
@@ -2038,6 +2039,20 @@ class Vector
self / n
end
+ #
+ # Returns an angle with another vector. Result is within the [0...Math::PI].
+ # Vector[1,0].angle_with(Vector[0,1])
+ # # => Math::PI / 2
+ #
+ def angle_with(v)
+ raise TypeError, "Expected a Vector, got a #{v.class}" unless v.is_a?(Vector)
+ Vector.Raise ErrDimensionMismatch if size != v.size
+ prod = magnitude * v.magnitude
+ raise ZeroVectorError, "Can't get angle of zero vector" if prod == 0
+
+ Math.acos( inner_product(v) / prod )
+ end
+
#--
# CONVERTING
#++
diff --git a/test/matrix/test_vector.rb b/test/matrix/test_vector.rb
index a063d2ca12..9607755feb 100644
--- a/test/matrix/test_vector.rb
+++ b/test/matrix/test_vector.rb
@@ -182,4 +182,15 @@ class TestVector < Test::Unit::TestCase
assert_raise(ArgumentError) { Vector[1, 2].cross_product(Vector[2, -1]) }
assert_raise(Vector::ErrOperationNotDefined) { Vector[1].cross_product }
end
+
+ def test_angle_with
+ assert_in_epsilon(Math::PI, Vector[1, 0].angle_with(Vector[-1, 0]))
+ assert_in_epsilon(Math::PI/2, Vector[1, 0].angle_with(Vector[0, -1]))
+ assert_in_epsilon(Math::PI/4, Vector[2, 2].angle_with(Vector[0, 1]))
+ assert_in_delta(0.0, Vector[1, 1].angle_with(Vector[1, 1]), 0.00001)
+
+ assert_raise(Vector::ZeroVectorError) { Vector[1, 1].angle_with(Vector[0, 0]) }
+ assert_raise(Vector::ZeroVectorError) { Vector[0, 0].angle_with(Vector[1, 1]) }
+ assert_raise(Matrix::ErrDimensionMismatch) { Vector[1, 2, 3].angle_with(Vector[0, 1]) }
+ end
end