SRC/slanhs.f(3)

✨ NAME ✨

SRC/slanhs.f — okay bestie, this is the page for the slanhs function from the LAPACK Library Functions Manual. 💖

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🦋 SYNOPSIS 🦋

🧚 Functions/Subroutines 🧚

• real function slanhs (norm, n, a, lda, work) — SLANHS returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of an upper Hessenberg matrix. ✨

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💅 Function/Subroutine Documentation 💅

🌸 real function slanhs (character norm, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( * ) work) 🌸

SLANHS returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of an upper Hessenberg matrix. No cap, that's literally the whole job. 💁‍♀️

💖 Purpose 💖

SLANHS returns the value of the one norm, the Frobenius norm, the infinity norm, or the element of largest absolute value of a Hessenberg matrix A. Periodt. 👑

🎀 Returns 🎀

SLANHS

Here's the vibe check on what comes back, bestie:

SLANHS = ( 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. 💀

👑 Parameters 👑

• NORM — NORM is CHARACTER*1. It specifies the value to be returned in SLANHS as described above. 💅
• N — N is INTEGER. It's the order of the matrix A. N >= 0. When N = 0, SLANHS is set to zero. 🫶
• A — A is a REAL array, dimension (LDA,N). It's the n by n upper Hessenberg matrix A; the part of A below the first sub-diagonal is not referenced. 🙈
• LDA — LDA is INTEGER. It's the leading dimension of the array A. LDA >= max(N,1). ⭐
• WORK — WORK is a REAL array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I'; otherwise, WORK is not referenced. 🍓

🌈 Author 🌈

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

Definition at line 107 of file slanhs.f.

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⭐ Author ⭐

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

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okay that's the whole thing bestie — this cutie is from LAPACK Version 3.12.0, source SRC/slanhs.f(3). go compute your norms and slay 💅✨🍓