ASKSAGE: Sage Q&A Forum - Individual question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Mon, 04 May 2015 10:05:12 -0500LU decomposition for a matrixhttp://ask.sagemath.org/question/26713/lu-decomposition-for-a-matrix/ There is an inconsistency in the use of the LU decomposition of a matrix. If matrix A is declared in the RDF ring then P, L, U = A.LU () provides PA = LU but if A is declared in the RR ring (or QQ, ZZ,...) then A = PLU. Therefore in a case P is P.transpose () on the other.Mon, 04 May 2015 08:59:21 -0500http://ask.sagemath.org/question/26713/lu-decomposition-for-a-matrix/Answer by tmonteil for <p>There is an inconsistency in the use of the LU decomposition of a matrix. If matrix A is declared in the RDF ring then P, L, U = A.LU () provides PA = LU but if A is declared in the RR ring (or QQ, ZZ,...) then A = PLU. Therefore in a case P is P.transpose () on the other.</p>
http://ask.sagemath.org/question/26713/lu-decomposition-for-a-matrix/?answer=26714#post-id-26714While this is correctly documented (hence not a bug), i agree that there is some inconsistency here. Thanks for reporting, it is now [trac ticket 18365](http://trac.sagemath.org/ticket/18365).
Mon, 04 May 2015 10:05:12 -0500http://ask.sagemath.org/question/26713/lu-decomposition-for-a-matrix/?answer=26714#post-id-26714