ruby-changes:20419
From: marcandre <ko1@a...>
Date: Sat, 9 Jul 2011 11:41:23 +0900 (JST)
Subject: [ruby-changes:20419] marcandRe: r32467 (trunk): * lib/matrix.rb: Add Vector#normalize
marcandre 2011-07-09 11:41:14 +0900 (Sat, 09 Jul 2011) New Revision: 32467 http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=32467 Log: * lib/matrix.rb: Add Vector#normalize [ruby-dev:43829] Modified files: trunk/ChangeLog trunk/NEWS trunk/lib/matrix.rb Index: ChangeLog =================================================================== --- ChangeLog (revision 32466) +++ ChangeLog (revision 32467) @@ -1,3 +1,7 @@ +Sat Jul 9 11:41:03 2011 Marc-Andre Lafortune <ruby-core@m...> + + * lib/matrix.rb: Add Vector#normalize [ruby-dev:43829] + Sat Jul 9 09:25:06 2011 Eric Hodel <drbrain@s...> * enumerator.c: Remove "enumeration sequenced by". Index: lib/matrix.rb =================================================================== --- lib/matrix.rb (revision 32466) +++ lib/matrix.rb (revision 32467) @@ -1517,8 +1517,11 @@ # 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> # @@ -1778,7 +1781,31 @@ 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 #++ Index: NEWS =================================================================== --- NEWS (revision 32466) +++ NEWS (revision 32467) @@ -182,7 +182,8 @@ * Matrix#unitary? * Matrix#upper_triangular? * Matrix#zero? - * Vector#magnitude + * Vector#magnitude, #norm + * Vector#normalize * extended methods: * Matrix#each and #each_with_index can iterate on a subset of the elements * Matrix#find_index returns [row, column] and can iterate on a subset -- ML: ruby-changes@q... Info: http://www.atdot.net/~ko1/quickml/