STPTTR(3)

🌸 NAME 🌸

okay bestie, welcome to stpttr.f(3) — it's a LAPACK page filed under Library Functions Manual, and the header/footer path vibes as /home/abui...RC/stpttr.f(3). The actual source file named in NAME is:

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

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine STPTTR (uplo, n, ap, a, lda, info)
    STPTTR copies a triangular matrix from the standard packed format
    (TP) to the standard full format (TR).

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💅 Function/Subroutine Documentation 💅

subroutine STPTTR (character uplo, integer n, real, dimension( * ) ap, real,
    dimension( lda, * ) a, integer lda, integer info)

The whole main-character move: STPTTR copies a triangular matrix from the standard packed format (TP) into the standard full format (TR). No cap.

🎀 Purpose 🎀

!>
!> STPTTR copies a triangular matrix A from standard packed format (TP)
!> to standard full format (TR).
!>

tl;dr: it moves triangular matrix A from packed TP land into full TR land. Obsessed.

🦋 Parameters 🦋

UPLO

UPLO is CHARACTER*1 — it picks which triangle is the moment:

• = 'U': A is upper triangular.
• = 'L': A is lower triangular.

N

N is INTEGER, the order of the matrix A. N >= 0.

AP

AP is a REAL array, dimension ( N*(N+1)/2 ). On entry, it's the upper or lower triangular matrix A, packed columnwise in a linear array. The j-th column of A is stored in AP like this:

• 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.

A

A is a REAL array, dimension ( LDA, N ). On exit, it's the triangular 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.

literally do not expect the unreferenced triangle to be read, bestie.

LDA

LDA is INTEGER, the leading dimension of the array A. LDA >= max(1,N).

INFO

INFO is INTEGER:

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value

💖 Author 💖

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

Definition at line 103 of file stpttr.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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sign-off: this page is from LAPACK Version 3.12.0, source/header path /home/abui...RC/stpttr.f(3), and since it was generated automatically there's no separate date printed on the page. 🫶✨