ZLANSY(3)

💅 ZLANSY(3) — Library Functions Manual 💅

Okay bestie, welcome to the ZLANSY(3) page from the Library Functions Manual. The header tags it with /home/abui...RC/zlansy.f(3), and the full source path is waiting for you in NAME below.

🌸 NAME 🌸

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

That's the file this page documents. Periodt.

✨ SYNOPSIS ✨

🧚 Functions/Subroutines

double precision function ZLANSY (norm, uplo, n, a, lda, work)

This is the shorthand: ZLANSY returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex symmetric matrix. Lowkey iconic. ✨

💖 Function/Subroutine Documentation 💖

🌈 ZLANSY

Here's the full type-and-argument reveal, no cap:

double precision function ZLANSY (character norm, character uplo, integer n,
    complex*16, dimension( lda, * ) a, integer lda, double precision,
    dimension( * ) work)

Same function, full signature energy. 🫶

🎀 Purpose: 🎀

ZLANSY returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex symmetric matrix A.

That's the whole point. It's giving norm-selector main character. 👑

⭐ Returns

The return value is ZLANSY, and it picks based on NORM like this:

!>
!>    ZLANSY = ( max(abs(A(i,j))), NORM = 'M' or 'm'
!>             (
!>             ( norm1(A),         NORM = '1', 'O' or 'o'
!>             (
!>             ( normI(A),         NORM = 'I' or 'i'
!>             (
!>             ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
!>
!> where  norm1  denotes the  one norm of a matrix (maximum column sum),
!> normI  denotes the  infinity norm  of a matrix  (maximum row sum) and
!> normF  denotes the  Frobenius norm of a matrix (square root of sum of
!> squares).  Note that  max(abs(A(i,j)))  is not a consistent matrix norm.
!>

Quick translation, bestie: norm1 is the one norm of a matrix (maximum column sum), normI is the infinity norm of a matrix (maximum row sum), and normF is the Frobenius norm of a matrix (square root of sum of squares). Also important: max(abs(A(i,j))) is not a consistent matrix norm. Noted. 💀

🔥 Parameters

• NORM — NORM is CHARACTER*1. It specifies the value to be returned in ZLANSY as described above.
• UPLO — UPLO is CHARACTER*1. It specifies whether the upper or lower triangular part of the symmetric matrix A is to be referenced.
  • = 'U': Upper triangular part of A is referenced.
  • = 'L': Lower triangular part of A is referenced.
• N — N is INTEGER. The order of the matrix A. N >= 0. When N = 0, ZLANSY is set to zero.
• A — A is COMPLEX*16 array, dimension (LDA,N). The symmetric matrix A. If UPLO = 'U', the leading n by n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(N,1).
• WORK — WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK is not referenced.

👑 Author

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

Definition at line 122 of file zlansy.f.

🦋 Author 🦋

Generated automatically by Doxygen for LAPACK from the source code.

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Bestie, that's the whole page. Footer check: LAPACK — Version 3.12.0 — /home/abui...RC/zlansy.f(3). No separate date is printed on that line, just those source/version vibes. 🫶