TESTING/LIN/dlavsp.f(3)

✨ TESTING/LIN/dlavsp.f ✨

okay bestie, so this is from the Library Functions Manual and it's literally all about dlavsp.f — a Fortran subroutine that's giving major main character energy in the LAPACK testing world 💅✨

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🎀 SYNOPSIS 🎀

Functions/Subroutines

• subroutine dlavsp (uplo, trans, diag, n, nrhs, a, ipiv, b, ldb, info) — DLAVSP

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💖 Function/Subroutine Documentation 💖

🌸 subroutine dlavsp (character uplo, character trans, character diag, integer n, integer nrhs, double precision, dimension( * ) a, integer, dimension( * ) ipiv, double precision, dimension( ldb, * ) b, integer ldb, integer info) 🌸

DLAVSP — slay

🦋 Purpose 🦋

okay so DLAVSP performs one of the matrix-vector operations fortran x := A*x or x := A'*x, where x is an N element vector and A is one of the factors from the block U*D*U' or L*D*L' factorization computed by DSPTRF. If TRANS = 'N', multiplies by U or U * D (or L or L * D) If TRANS = 'T', multiplies by U' or D * U' (or L' or D * L') If TRANS = 'C', multiplies by U' or D * U' (or L' or D * L') periodt. 💅

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🌈 Parameters 🌈

• UPLO — UPLO is CHARACTER*1. Specifies whether the factor stored in A is upper or lower triangular.
  • = 'U': Upper triangular 🔼
  • = 'L': Lower triangular 🔽
• TRANS — TRANS is CHARACTER*1. Specifies the operation to be performed:
  • = 'N': x := A*x
  • = 'T': x := A'*x
  • = 'C': x := A'*x
• DIAG — DIAG is CHARACTER*1. Specifies whether or not the diagonal blocks are unit matrices. If the diagonal blocks are assumed to be unit, then A = U or A = L, otherwise A = U*D or A = L*D.
  • = 'U': Diagonal blocks are assumed to be unit matrices. ✨
  • = 'N': Diagonal blocks are assumed to be non-unit matrices.
• N — N is INTEGER. The number of rows and columns of the matrix A. N >= 0. fr fr
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of vectors x to be multiplied by A. NRHS >= 0. no cap
• A — A is DOUBLE PRECISION array, dimension (N*(N+1)/2). The block diagonal matrix D and the multipliers used to obtain the factor U or L, stored as a packed triangular matrix as computed by DSPTRF. iconic 💖
• IPIV — IPIV is INTEGER array, dimension (N). The pivot indices from DSPTRF.
• B — B is DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, B contains NRHS vectors of length N. On exit, B is overwritten with the product A * B. 🦋
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• INFO — INFO is INTEGER.
  • = 0: successful exit 🎉
  • < 0: if INFO = -k, the k-th argument had an illegal value 💀

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👑 Author 👑

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 128 of file dlavsp.f.

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🌟 Author: Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie that's the whole vibe of dlavsp.f — like, it's giving "I'm a serious numerical linear algebra routine but make it cute" and honestly? we're obsessed. 💅✨

LAPACK Version 3.12.0 🌸 — signing off, your fave Fortran bestie 🫶💖