BLAS/SRC/ctrmv.f(3)

💖 BLAS/SRC/ctrmv.f(3) 💖

okay so this page is from the Library Functions Manual, and it is literally about BLAS/SRC/ctrmv.f(3). We are in group-chat mode, but the facts are staying put, bestie. 💅

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🌸 NAME 🌸

BLAS/SRC/ctrmv.f

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine ctrmv (uplo, trans, diag, n, a, lda, x, incx)
       CTRMV

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🦋 Function/Subroutine Documentation 🦋

subroutine ctrmv (character uplo, character trans, character diag, integer
       n, complex, dimension(lda,*) a, integer lda, complex, dimension(*) x,
       integer incx)
       CTRMV

💖 Purpose 💖

okay so CTRMV performs one of these matrix-vector operations:

x := A*x,   or   x := A**T*x,   or   x := A**H*x,

where x is an n element vector and A is an n by n unit, or non-unit, upper or lower triangular matrix. ✨

🎀 Parameters 🎀

💅 UPLO

UPLO is CHARACTER*1. On entry, UPLO specifies whether the matrix is an upper or lower triangular matrix as follows:

• UPLO = 'U' or 'u' — A is an upper triangular matrix.
• UPLO = 'L' or 'l' — A is a lower triangular matrix.

💅 TRANS

TRANS is CHARACTER*1. On entry, TRANS specifies the operation to be performed as follows:

• TRANS = 'N' or 'n' — x := A*x.
• TRANS = 'T' or 't' — x := A**T*x.
• TRANS = 'C' or 'c' — x := A**H*x.

💅 DIAG

DIAG is CHARACTER*1. On entry, DIAG specifies whether or not A is unit triangular as follows:

• DIAG = 'U' or 'u' — A is assumed to be unit triangular.
• DIAG = 'N' or 'n' — A is not assumed to be unit triangular.

💅 N

N is INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero.

🚨 bestie, that means N must be at least zero — no sneaky negatives.

💅 A

A is COMPLEX array, dimension ( LDA, N ).

Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array A must contain the upper triangular matrix and the strictly lower triangular part of A is not referenced.

Before entry with UPLO = 'L' or 'l', the leading n by n lower triangular part of the array A must contain the lower triangular matrix and the strictly upper triangular part of A is not referenced.

Note that when DIAG = 'U' or 'u', the diagonal elements of A are not referenced either, but are assumed to be unity. 🫶

💅 LDA

LDA is INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least max( 1, n ).

💅 X

X is COMPLEX array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ).

Before entry, the incremented array X must contain the n element vector x. On exit, X is overwritten with the transformed vector x. 💖

💅 INCX

INCX is INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero.

🚨 INCX must not be zero. This is not a drill, bestie.

👑 Author 👑

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

🌈 Further Details 🌈

Level 2 Blas routine.

The vector and matrix arguments are not referenced when N = 0, or M = 0

-- Written on 22-October-1986.

• Jack Dongarra, Argonne National Lab.
• Jeremy Du Croz, Nag Central Office.
• Sven Hammarling, Nag Central Office.
• Richard Hanson, Sandia National Labs.

Definition at line 146 of file ctrmv.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 page. The footer is giving LAPACK Version 3.12.0, source tag BLAS/SRC/ctrmv.f(3), and there’s no separate date in it — so that’s the sign-off, periodt. 💖✨🫶