TESTING/LIN/crqt02.f(3)
π TESTING/LIN/crqt02.f π
okay bestie, welcome to the Library Functions Manual β this page is literally TESTING/LIN/crqt02.f, and it's all about the crqt02 subroutine. no cap, it's a LAPACK testing routine and it's giving βI check the math so you don't have to.β π
β¨ NAME β¨
TESTING/LIN/crqt02.f β that's the file, bestie. π
π¦ SYNOPSIS π¦
πΌ Functions/Subroutines πΌ
subroutine crqt02 (m, n, k, a, af, q, r, lda, tau, work, lwork, rwork,
result)
CRQT02 π₯
π Function/Subroutine Documentation π
subroutine crqt02 (integer m, integer n, integer k, complex, dimension( lda,
* ) a, complex, dimension( lda, * ) af, complex, dimension( lda, * ) q,
complex, dimension( lda, * ) r, integer lda, complex, dimension( * )
tau, complex, dimension( lwork ) work, integer lwork, real, dimension( *
) rwork, real, dimension( * ) result)
CRQT02 β¨
πΈ Purpose πΈ
bestie, here's the tea: CRQT02 tests CUNGRQ, which generates an m-by-n matrix Q with orthonormal rows that is defined as the product of k elementary reflectors. π
Given the RQ factorization of an m-by-n matrix A, CRQT02 generates the orthogonal matrix Q defined by the factorization of the last k rows of A; it compares R(m-k+1:m,n-m+1:n) with A(m-k+1:m,1:n)*Q(n-m+1:n,1:n)', and checks that the rows of Q are orthonormal. periodt. π
π Parameters π
MβM is INTEGERβ the number of rows of the matrixQto be generated.M >= 0. πNβN is INTEGERβ the number of columns of the matrixQto be generated.N >= M >= 0. πKβK is INTEGERβ the number of elementary reflectors whose product defines the matrixQ.M >= K >= 0. πAβA is COMPLEX array, dimension (LDA,N)β the m-by-n matrixAwhich was factorized byCRQT01. π¦AFβAF is COMPLEX array, dimension (LDA,N)β details of the RQ factorization ofA, as returned byCGERQF. SeeCGERQFfor further details. π¦QβQ is COMPLEX array, dimension (LDA,N)β that's the array itself, no extra notes. πRβR is COMPLEX array, dimension (LDA,M)β theRarray itself, living its best life. πLDAβLDA is INTEGERβ the leading dimension of the arraysA,AF,QandL.LDA >= N. πTAUβTAU is COMPLEX array, dimension (M)β the scalar factors of the elementary reflectors corresponding to the RQ factorization inAF. πWORKβWORK is COMPLEX array, dimension (LWORK)β that's the spec, bestie. βLWORKβLWORK is INTEGERβ the dimension of the arrayWORK. βRWORKβRWORK is REAL array, dimension (M)β that's the whole spec. πΈRESULTβRESULT is REAL array, dimension (2)β the test ratios, and they are:
RESULT(1) = norm( R - A*Q' ) / ( N * norm(A) * EPS )
RESULT(2) = norm( I - Q*Q' ) / ( N * EPS )
those are the exact ratios, no cap. π₯
π Author π
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Definition at line 134 of file crqt02.f. π
π Author π
Generated automatically by Doxygen for LAPACK from the source code. π«Ά
mwah π β that's the whole page, bestie! the footer says LAPACK Version 3.12.0 and TESTING/LIN/crqt02.f(3); no date listed, so I'm not inventing one. πβ¨
π¦ where this page comes from
- arch rolling: lapack-doc 3.12.1-2 Β· custom
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms