SRC/clansy.f(3)

💖 NAME 💖

SRC/clansy.f — that’s this page’s name, bestie. The actual star is clansy, and she’s here to return 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. Norm queen behavior, honestly. 👑

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✨ SYNOPSIS ✨

🌈 Functions/Subroutines

• real function clansy (norm, uplo, n, a, lda, work) — CLANSY 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.

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🎀 Function/Subroutine Documentation 🎀

Here’s the full signature, copied with love and zero edits:

   real function clansy (character norm, character uplo, integer n, complex,
       dimension( lda, * ) a, integer lda, real, dimension( * ) work)

CLANSY 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. Yup, that’s the whole vibe. 💅

💜 Purpose

The original says it like this, and we’re keeping it exactly:

!>
!> CLANSY  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.
!>

🌸 Returns

CLANSY returns one of these, depending on NORM:

!>
!>    CLANSY = ( 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.
!>

Heads up, bestie: max(abs(A(i,j))) is not a consistent matrix norm. That’s a direct warning from the original, so don’t come for me — I’m just the messenger. 😭

🦋 Parameters

🌟 NORM

NORM is CHARACTER*1. It specifies the value to be returned in CLANSY as described above. It’s literally the “which norm are we doing today?” selector.

🌟 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. It’s the order of the matrix A. N >= 0. When N = 0, CLANSY is set to zero.

🌟 A

A is COMPLEX array, dimension (LDA,N). It’s 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. It’s the leading dimension of the array A. LDA >= max(N,1).

🌟 WORK

WORK is REAL 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 clansy.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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This page came from SRC/clansy.f(3) in the Library Functions Manual, and the footer says LAPACK Version 3.12.0. The footer didn’t include a date, so I’m not inventing one — mystery era, honestly 🕵️‍♀️. Bye bestie, go compute a norm for me 💖✨