BLAS/SRC/ctpsv.f(3)

💖 NAME 💖

BLAS/SRC/ctpsv.f — that's the file, bestie. This page comes from the BLAS/SRC/ctpsv.f(3) Library Functions Manual, and it's the CTPSV subroutine's whole moment. ✨

🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine ctpsv (uplo, trans, diag, n, ap, x, incx)
    CTPSV

🌸 Function/Subroutine Documentation 🌸

subroutine ctpsv (character uplo, character trans, character diag, integer
    n, complex, dimension(*) ap, complex, dimension(*) x, integer incx)
    CTPSV

✨ Purpose ✨

okay so CTPSV solves one of the systems of equations

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

where b and x are n element vectors and A is an n by n unit, or non-unit, upper or lower triangular matrix, supplied in packed form. 🫶

🚨 bestie, listen: no test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine. no cap.

🧚 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 equations to be solved as follows:

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

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.

AP

AP is COMPLEX array, dimension at least ( ( n*( n + 1 ) )/2 ).

Before entry with UPLO = 'U' or 'u', the array AP must contain the upper triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively, and so on. 🍓

Before entry with UPLO = 'L' or 'l', the array AP must contain the lower triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on. 🍓

note bestie: when DIAG = 'U' or 'u', the diagonal elements of A are not referenced, but are assumed to be unity. 💅

X

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

Before entry, the incremented array X must contain the n element right-hand side vector b. On exit, X is overwritten with the solution vector x. 🔥

INCX

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

👑 Author 👑

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

🔥 Further Details: 🔥

• Level 2 Blas routine.
• -- 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 143 of file ctpsv.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie! 💖 source/version sign-off: LAPACK, Version 3.12.0, and the page is BLAS/SRC/ctpsv.f(3). mwah 💋