NAME

ZTRMVT - perform the matrix-vector operations x := conjg( T' ) *y, and w := T *z,

SYNOPSIS

SUBROUTINE ZTRMVT(

UPLO, N, T, LDT, X, INCX, Y, INCY, W, INCW, Z, INCZ )

CHARACTER UPLO INTEGER INCW, INCX, INCY, INCZ, LDT, N COMPLEX*16 T( LDT, * ), W( * ), X( * ), Y( * ), Z( * )

PURPOSE

ZTRMVT performs the matrix-vector operations x := conjg( T' ) *y, and w := T *z, where x is an n element vector and T is an n by n upper or lower triangular matrix.

ARGUMENTS

UPLO - 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.

Unchanged on exit.

N - INTEGER.

On entry, N specifies the order of the matrix A. N must be at least zero. Unchanged on exit.

T - COMPLEX*16 array of DIMENSION ( LDT, n ).

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

LDT - 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 ). Unchanged on exit.

X - COMPLEX*16 array of dimension at least

( 1 + ( n - 1 )*abs( INCX ) ). On exit, X = T' * y

INCX - INTEGER.

On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Unchanged on exit.

Y - COMPLEX*16 array of dimension at least

( 1 + ( n - 1 )*abs( INCY ) ). Before entry, the incremented array Y must contain the n element vector y. Unchanged on exit.

INCY - INTEGER.

On entry, INCY specifies the increment for the elements of Y. INCY must not be zero. Unchanged on exit.

W - COMPLEX*16 array of dimension at least

( 1 + ( n - 1 )*abs( INCW ) ). On exit, W = T * z

INCW - INTEGER.

On entry, INCW specifies the increment for the elements of W. INCW must not be zero. Unchanged on exit.

Z - COMPLEX*16 array of dimension at least

( 1 + ( n - 1 )*abs( INCZ ) ). Before entry, the incremented array Z must contain the n element vector z. Unchanged on exit.

INCY - INTEGER.

On entrz, INCY specifies the increment for the elements of Y. INCY must not be zero. Unchanged on exit.

Level 2 Blas routine.

Test the input parameters.

Quick return if possible.

End of ZTRMVT.