ZSYCONVF(3)

🌸 NAME 🌸

okay so bestie, this is the manual page for ZSYCONVF, aka zsyconvf.f(3) from the Library Functions Manual, and the source file is literally right here:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zsyconvf.f

The header path is written as /home/abui.../zsyconvf.f(3) — ellipsis and all, no cap. 💅

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✨ SYNOPSIS ✨

Under Functions/Subroutines, the vibe is:

subroutine ZSYCONVF (uplo, way, n, a, lda, e, ipiv, info)
    ZSYCONVF

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💖 Function/Subroutine Documentation 💖

subroutine ZSYCONVF (character uplo, character way, integer n, complex*16,
    dimension( lda, * ) a, integer lda, complex*16, dimension( * ) e,
    integer, dimension( * ) ipiv, integer info)
    ZSYCONVF

🦋 Purpose 🦋

Okay so here’s the tea, and it’s actually important:

If WAY = 'C': ZSYCONVF converts the factorization output format used in ZSYTRF — provided on entry in parameter A — into the factorization output format used in ZSYTRF_RK (or ZSYTRF_BK) that is stored on exit in parameters A and E. It also converts in place details of the interchanges stored in IPIV from the format used in ZSYTRF into the format used in ZSYTRF_RK (or ZSYTRF_BK). Slay.

If WAY = 'R': ZSYCONVF performs the conversion in reverse direction, i.e. converts the factorization output format used in ZSYTRF_RK (or ZSYTRF_BK) provided on entry in parameters A and E into the factorization output format used in ZSYTRF that is stored on exit in parameter A. It also converts in place details of the interchanges stored in IPIV from the format used in ZSYTRF_RK (or ZSYTRF_BK) into the format used in ZSYTRF. Periodt.

ZSYCONVF can also convert in Hermitian matrix case, i.e. between formats used in ZHETRF and ZHETRF_RK (or ZHETRF_BK). Iconic.

🎀 Parameters 🎀

🍓 UPLO

UPLO is CHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix A.

• = 'U': Upper triangular
• = 'L': Lower triangular

🍓 WAY

WAY is CHARACTER*1.

• = 'C': Convert
• = 'R': Revert

🍓 N

N is INTEGER. The order of the matrix A. N >= 0.

🍓 A

A is COMPLEX*16 array, dimension (LDA,N).

1. If WAY ='C':
   • On entry, contains factorization details in format used in ZSYTRF: a) all elements of the symmetric block diagonal matrix D on the diagonal of A and on superdiagonal (or subdiagonal) of A, and b) If UPLO = 'U': multipliers used to obtain factor U in the superdiagonal part of A. If UPLO = 'L': multipliers used to obtain factor L in the superdiagonal part of A.
   • On exit, contains factorization details in format used in ZSYTRF_RK or ZSYTRF_BK: a) ONLY diagonal elements of the symmetric block diagonal matrix D on the diagonal of A, i.e. D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements of D are stored on exit in array E), and b) If UPLO = 'U': factor U in the superdiagonal part of A. If UPLO = 'L': factor L in the subdiagonal part of A.
2. If WAY = 'R':
   • On entry, contains factorization details in format used in ZSYTRF_RK or ZSYTRF_BK: a) ONLY diagonal elements of the symmetric block diagonal matrix D on the diagonal of A, i.e. D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements of D are stored on exit in array E), and b) If UPLO = 'U': factor U in the superdiagonal part of A. If UPLO = 'L': factor L in the subdiagonal part of A.
   • On exit, contains factorization details in format used in ZSYTRF: a) all elements of the symmetric block diagonal matrix D on the diagonal of A and on superdiagonal (or subdiagonal) of A, and b) If UPLO = 'U': multipliers used to obtain factor U in the superdiagonal part of A. If UPLO = 'L': multipliers used to obtain factor L in the superdiagonal part of A.

🍓 LDA

LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).

🍓 E

E is COMPLEX*16 array, dimension (N).

1. If WAY ='C':
   • On entry, just a workspace.
   • On exit, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrix D with 1-by-1 or 2-by-2 diagonal blocks, where If UPLO = 'U': E(i) = D(i-1,i), i=2:N, E(1) is set to 0; If UPLO = 'L': E(i) = D(i+1,i), i=1:N-1, E(N) is set to 0.
2. If WAY = 'R':
   • On entry, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrix D with 1-by-1 or 2-by-2 diagonal blocks, where If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced; If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
   • On exit, is not changed

🍓 IPIV

IPIV is INTEGER array, dimension (N).

1. If WAY ='C':

• On entry, details of the interchanges and the block structure of D in the format used in ZSYTRF.
• On exit, details of the interchanges and the block structure of D in the format used in ZSYTRF_RK ( or ZSYTRF_BK).

1. If WAY ='R' — yep, the source says 1) again, not a typo from me, bestie:

• On entry, details of the interchanges and the block structure of D in the format used in ZSYTRF_RK ( or ZSYTRF_BK).
• On exit, details of the interchanges and the block structure of D in the format used in ZSYTRF.

🍓 INFO

INFO is INTEGER.

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value

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👑 Author 👑

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

🌈 Contributors: 🌈

November 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley

Definition at line 208 of file zsyconvf.f.

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📜 Author (the auto-generated one) 📜

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that’s the whole page. Footer tea: source/version is LAPACK Version 3.12.0, the page is /home/abui.../zsyconvf.f(3), and there’s no date printed in this footer — so I’m not gonna invent one. Mwah 💋✨