Bug #7582: a mistake in Matrix#lup RDoc

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.0.0dev (2012-11-01) [i386-mswin32_100]

[pypypy567 (py _)]

http://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/38300/entry/lib/matrix.rb#L1203

l * u == a * p # => true

http://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/38300/entry/lib/matrix/lup_decomposition.rb#L7

and a m-by-m permutation matrix P so that LU = PA.

irb(main):001:0> require 'matrix'
=> true
irb(main):002:0> a = Matrix[[1, 2], [3, 4]]
=> Matrix[[1, 2], [3, 4]]
irb(main):003:0> l, u, p = a.lup
=> #<Matrix::LUPDecomposition:0xf813a8 @lu=[[3, 4], [(1/3), (2/3)]], @row_size=2, @col_size=2, @pivots=[1, 0], @pivot_sign=-1>
irb(main):004:0> l * u == a * p
=> false
irb(main):005:0> l * u == p * a
=> true

[zzak (zzak _)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r38425.
py, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

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• lib/matrix.rb (#dup): typo in example [ruby-core:50946][Bug #7582]