DLANTP(3)

💖 DLANTP(3) 💖

okay so this is the Library Functions Manual entry for DLANTP(3), and she is lowkey iconic if you're into packed triangular matrices. no cap. 🫶

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✨ NAME ✨

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

that's the source file path, bestie. periodt.

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🌸 SYNOPSIS 🌸

Functions/Subroutines

• double precision function DLANTP (norm, uplo, diag, n, ap, work) — DLANTP returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular matrix supplied in packed form.

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🦋 Function/Subroutine Documentation 🦋

double precision function DLANTP

double precision function DLANTP (character norm, character uplo, character diag, integer n, double precision, dimension( * ) ap, double precision, dimension( * ) work)

DLANTP returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular matrix supplied in packed form.

💖 Purpose: 💖

DLANTP gives you the one norm, the Frobenius norm, the infinity norm, or the element of largest absolute value of a triangular matrix A, supplied in packed form. that's the whole assignment, bestie. 💅

⭐ Returns ⭐

DLANTP

!>
!>    DLANTP = ( 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 — is a CHARACTER*1. Specifies the value to be returned in DLANTP as described above.
• UPLO — is a CHARACTER*1. Specifies whether the matrix A is upper or lower triangular.
  • = 'U': Upper triangular
  • = 'L': Lower triangular
• DIAG — is a CHARACTER*1. Specifies whether or not the matrix A is unit triangular.
  • = 'N': Non-unit triangular
  • = 'U': Unit triangular
• N — is INTEGER. The order of the matrix A. N >= 0. When N = 0, DLANTP is set to zero.
• AP — is DOUBLE PRECISION array, dimension (N*(N+1)/2). The upper or lower triangular matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows:

if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.

Note that when DIAG = 'U', the elements of the array AP corresponding to the diagonal elements of the matrix A are not referenced, but are assumed to be one.

• WORK — is DOUBLE PRECISION 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 123 of file dlantp.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 page, bestie. this footer flex is from LAPACK Version 3.12.0, and the footer path is /home/abui...RC/dlantp.f(3). no date on this one, just vibes. 🫶