SLANGT(3)

💅 NAME

okay bestie, this page is slangt.f(3) from the Library Functions Manual — yes, that header vibe — and the NAME section is literally the source file path:

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

the header/footer shorthand is /home/abui...RC/slangt.f(3), iykyk. No cap, that's the whole NAME section. 💖

✨ SYNOPSIS ✨

Functions/Subroutines — it's giving "one function, big main character energy":

real function SLANGT (norm, n, dl, d, du)

SLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. Slay. 💅

🫶 Function/Subroutine Documentation

full signature, bestie:

real function SLANGT (character norm, integer n, real, dimension( * ) dl, real, dimension( * ) d, real, dimension( * ) du)

ngl, same tea: SLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. Obsessed with a clean signature.

🎀 Purpose

SLANGT is the vibe check for a real tridiagonal matrix A: it hands you the one norm, the Frobenius norm, the infinity norm, or the element with the largest absolute value, depending on NORM. That's the whole purpose, bestie. ✨

🌸 Returns

SLANGT returns one of these, based on NORM:

!>
!>    SLANGT = ( 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.
!>

Important note: max(abs(A(i,j))) is not a consistent matrix norm — the original says it and I'm not gonna pretend otherwise. Periodt. 💀

🦋 Parameters

NORM

NORM is CHARACTER*1. It specifies the value to be returned in SLANGT as described above. Pick your menu item, bestie.

N

N is INTEGER. The order of the matrix A. N >= 0. When N = 0, SLANGT is set to zero. Zero case is handled, no stress.

DL

DL is REAL array, dimension (N-1). The (n-1) sub-diagonal elements of A. Sub-diagonal cuties.

D

D is REAL array, dimension (N). The diagonal elements of A. Main diagonal main character energy.

DU

DU is REAL array, dimension (N-1). The (n-1) super-diagonal elements of A. Super-diagonal, super slay.

👑 Author

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

the author squad ate, fr fr 🌈

📍 Definition at line 105 of file slangt.f.

That's the exact spot: Definition at line 105 of file slangt.f. Lowkey iconic. 💖

🪄 Author

Generated automatically by Doxygen for LAPACK from the source code. Not me being auto-generated and still serving. 🫶

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Sign-off: LAPACK Version 3.12.0 is the source/version on the footer, and the footer date is literally not there — so consider this your official no-date, slangt.f(3) bestie goodbye. Mwah 💋🦋