CHST01(3)

🌸 NAME 🌸

Bestie, this is the manual page for chst01(3) — aka CHST01. The source path is exactly /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/chst01.f, no cap. 🦋

💫 SYNOPSIS 💫

🧚 Functions/Subroutines 🧚

subroutine CHST01 (n, ilo, ihi, a, lda, h, ldh, q, ldq, work, lwork, rwork, result)

CHST01 — that’s the name, she’s iconic. 👑

💅 Function/Subroutine Documentation 💅

subroutine CHST01 (integer n, integer ilo, integer ihi, complex, dimension( lda, * ) a, integer lda, complex, dimension( ldh, * ) h, integer ldh, complex, dimension( ldq, * ) q, integer ldq, complex, dimension( lwork ) work, integer lwork, real, dimension( * ) rwork, real, dimension( 2 ) result)

CHST01

🦋 Purpose 🦋

Okay so CHST01 tests the reduction of a general matrix A to upper Hessenberg form: A = Q*H*Q'. Two test ratios are computed, bestie:

• RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )
• RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )

The matrix Q is assumed to be given explicitly, as it would be following CGEHRD + CUNGHR. In this version, ILO and IHI are not used, but they could be used to save some work if this is desired. ✨

🌈 Parameters 🌈

• N — N is INTEGER. The order of the matrix A. N >= 0.
• ILO — ILO is INTEGER.
• IHI — IHI is INTEGER. A is assumed to be upper triangular in rows and columns 1:ILO-1 and IHI+1:N, so Q differs from the identity only in rows and columns ILO+1:IHI.
• A — A is COMPLEX array, dimension (LDA,N). The original n by n matrix A.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• H — H is COMPLEX array, dimension (LDH,N). The upper Hessenberg matrix H from the reduction A = Q*H*Q' as computed by CGEHRD. H is assumed to be zero below the first subdiagonal.
• LDH — LDH is INTEGER. The leading dimension of the array H. LDH >= max(1,N).
• Q — Q is COMPLEX array, dimension (LDQ,N). The orthogonal matrix Q from the reduction A = Q*H*Q' as computed by CGEHRD + CUNGHR.
• LDQ — LDQ is INTEGER. The leading dimension of the array Q. LDQ >= max(1,N).
• WORK — WORK is COMPLEX array, dimension (LWORK).
• LWORK — LWORK is INTEGER. The length of the array WORK. LWORK >= 2*N*N.
• RWORK — RWORK is REAL array, dimension (N).
• RESULT — RESULT is REAL array, dimension (2). RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS ) RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )

👑 Author 👑

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Definition at line 138 of file chst01.f.

✨ Author ✨

Generated automatically by Doxygen for LAPACK from the source code.

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Catch you later, bestie! This cutie page comes from LAPACK Version 3.12.0, file /home/abui...IG/chst01.f(3) — mwah 💋✨