CLANTR(3)

💅 NAME — clantr.f(3) — Library Functions Manual 💅

okay bestie, this is the clantr.f(3) page from the Library Functions Manual, and it's all about this file: /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/clantr.f 💖

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✨ SYNOPSIS ✨

Functions/Subroutines:

real function CLANTR (norm, uplo, diag, m, n, a, lda, work)

Real function, no cap: CLANTR returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix. slay 🔥

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🦋 Function/Subroutine Documentation 🦋

🌸 real function CLANTR 🌸

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

CLANTR returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix. periodt 💅

💖 Purpose 💖

okay so the whole point: CLANTR returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix A. that's the vibe 🫶

⭐ Returns ⭐

Returns CLANTR, and the receipts are literally this:

!>
!>    CLANTR = ( 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.
!>

so yes, max(abs(A(i,j))) is not a consistent matrix norm — important caveat, bestie, don't forget it 😭

🎀 Parameters 🎀

• NORM — NORM is CHARACTER*1. Specifies the value to be returned in CLANTR as described above. iykyk ✨
• UPLO — UPLO is CHARACTER*1. Specifies whether the matrix A is upper or lower trapezoidal.
  • = 'U': Upper trapezoidal
  • = 'L': Lower trapezoidal Note that A is triangular instead of trapezoidal if M = N. 🦋
• DIAG — DIAG is CHARACTER*1. Specifies whether or not the matrix A has unit diagonal.
  • = 'N': Non-unit diagonal
  • = 'U': Unit diagonal
• M — M is INTEGER. The number of rows of the matrix A. M >= 0, and if UPLO = 'U', M <= N. When M = 0, CLANTR is set to zero. 🍓
• N — N is INTEGER. The number of columns of the matrix A. N >= 0, and if UPLO = 'L', N <= M. When N = 0, CLANTR is set to zero. 🌸
• A — A is COMPLEX array, dimension (LDA,N). The trapezoidal matrix A (A is triangular if M = N). If UPLO = 'U', the leading m by n upper trapezoidal part of the array A contains the upper trapezoidal matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading m by n lower trapezoidal part of the array A contains the lower trapezoidal matrix, and the strictly upper triangular part of A is not referenced. Note that when DIAG = 'U', the diagonal elements of A are not referenced and are assumed to be one. 💜
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(M,1). 🔥
• WORK — WORK is REAL array, dimension (MAX(1,LWORK)), where LWORK >= M when NORM = 'I'; otherwise, WORK is not referenced. no notes, that's exactly it 💅

👑 Author 👑

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

Definition at line 140 of file clantr.f.

🧚 Author 🧚 (generated)

Generated automatically by Doxygen for LAPACK from the source code. 🫶

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okay bestie, that's the whole page! source/version: LAPACK Version 3.12.0, and the footer path is /home/abui...RC/clantr.f(3). date: not listed on this page, so no cap there. bye bestie 💖✨🎀