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authormarcandre <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-07-09 02:41:14 +0000
committermarcandre <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2011-07-09 02:41:14 +0000
commit1e696acc7e86a6d57fe6afa91c7478420c62bc2b (patch)
tree9fdc14c700db920432aacb6ae429389a88a5ad6f /lib/matrix.rb
parentd137810d3a79e42b8ea7a52b04df0d3d1bc03ab9 (diff)
* lib/matrix.rb: Add Vector#normalize [ruby-dev:43829]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32467 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'lib/matrix.rb')
-rw-r--r--lib/matrix.rb27
1 files changed, 27 insertions, 0 deletions
diff --git a/lib/matrix.rb b/lib/matrix.rb
index b4ff31a..360e79f 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1517,8 +1517,11 @@ end
# Vector functions:
# * <tt> #inner_product(v) </tt>
# * <tt> #collect </tt>
+# * <tt> #magnitude </tt>
# * <tt> #map </tt>
# * <tt> #map2(v) </tt>
+# * <tt> #norm </tt>
+# * <tt> #normalize </tt>
# * <tt> #r </tt>
# * <tt> #size </tt>
#
@@ -1778,6 +1781,30 @@ class Vector
Math.sqrt(@elements.inject(0) {|v, e| v + e*e})
end
alias r magnitude
+ alias norm magnitude
+
+ #
+ # Like Vector#collect2, but returns a Vector instead of an Array.
+ #
+ def map2(v, &block) # :yield: e1, e2
+ return to_enum(:map2, v) unless block_given?
+ els = collect2(v, &block)
+ Vector.elements(els, false)
+ end
+
+ class ZeroVectorError < StandardError
+ end
+ #
+ # Returns a new vector with the same direction but with norm 1.
+ # v = Vector[5,8,2].normalize
+ # # => Vector[0.5184758473652127, 0.8295613557843402, 0.20739033894608505]
+ # v.norm => 1.0
+ #
+ def normalize
+ n = magnitude
+ raise ZeroVectorError, "Zero vectors can not be normalized" if n == 0
+ self / n
+ end
#--
# CONVERTING