Bug in Factor
Factor gives a different answer.
If Ruby and Octave are correct, then is a normal matrix. If Factor is correct, then is not a normal matrix. Factor is wrong. Factor's matrix multiplication has a bug: Factor confuses Hermitian inner product with scalar product, and calculates A × B in place of A × B. --Kernigh 00:30, 17 March 2012 (UTC)
Under-tested cosmetic edits made to the task page at 23:08, 14 August 2016, including the injection of spaces around expressions in <math> tags, left some or all of the task description formulae completely invisible to all browsers which display the graphic file version of formulae rather than processing the MathML (this is, in fact, the majority of browsers). The MediaWiki processor does not currently expect such spaces, and generates syntactically ill-formed HTML if they are introduced. Other aspects of these cosmetic edits may further compound the problem. Hout (talk) 10:10, 22 September 2016 (UTC)
- Some but not all of the introduced invisibility has now been repaired by individual edits removing the redundant spaces that were added to the <math> tag. For full repair it may prove necessary to simply undo the edit of 23:08, 14 August 2016 Hout (talk) 10:10, 22 September 2016 (UTC)
Ruby bug fixed in head
Matrix#hermitian?has been fixed in ruby 2.0