CTPMV (3) Linux Manual Page

ctpmv.f –

Synopsis

Functions/Subroutines

subroutine ctpmv (UPLO, TRANS, DIAG, N, AP, X, INCX)
CTPMV

Function/Subroutine Documentation

subroutine ctpmv (characterUPLO, characterTRANS, characterDIAG, integerN, complex, dimension(*)AP, complex, dimension(*)X, integerINCX)

CTPMV Purpose:

 CTPMV performs one of the 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, supplied in packed form.

 

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.

AP

 AP is COMPLEX array of 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 that when DIAG = ‘U’ or ‘u’, the diagonal elements of

 A are not referenced, but are assumed to be unity.

X

 X is COMPLEX array of 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

 tranformed 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.

Date:

November 2011

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 143 of file ctpmv.f.

Author

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