
dlagtm.f(3) LAPACK dlagtm.f(3)
NAME
dlagtm.f 
SYNOPSIS
Functions/Subroutines
subroutine dlagtm (TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB)
DLAGTM performs a matrixmatrix product of the form C = aAB+BC, where A is a
tridiagonal matrix, B and C are rectangular matrices, and a and B are scalars, which
may be 0, 1, or 1.
Function/Subroutine Documentation
subroutine dlagtm (characterTRANS, integerN, integerNRHS, double precisionALPHA, double
precision, dimension( * )DL, double precision, dimension( * )D, double precision,
dimension( * )DU, double precision, dimension( ldx, * )X, integerLDX, double
precisionBETA, double precision, dimension( ldb, * )B, integerLDB)
DLAGTM performs a matrixmatrix product of the form C = aAB+BC, where A is a tridiagonal
matrix, B and C are rectangular matrices, and a and B are scalars, which may be 0, 1, or
1.
Purpose:
DLAGTM performs a matrixvector product of the form
B := alpha * A * X + beta * B
where A is a tridiagonal matrix of order N, B and X are N by NRHS
matrices, and alpha and beta are real scalars, each of which may be
0., 1., or 1.
Parameters:
TRANS
TRANS is CHARACTER*1
Specifies the operation applied to A.
= 'N': No transpose, B := alpha * A * X + beta * B
= 'T': Transpose, B := alpha * A'* X + beta * B
= 'C': Conjugate transpose = Transpose
N
N is INTEGER
The order of the matrix A. N >= 0.
NRHS
NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrices X and B.
ALPHA
ALPHA is DOUBLE PRECISION
The scalar alpha. ALPHA must be 0., 1., or 1.; otherwise,
it is assumed to be 0.
DL
DL is DOUBLE PRECISION array, dimension (N1)
The (n1) subdiagonal elements of T.
D
D is DOUBLE PRECISION array, dimension (N)
The diagonal elements of T.
DU
DU is DOUBLE PRECISION array, dimension (N1)
The (n1) superdiagonal elements of T.
X
X is DOUBLE PRECISION array, dimension (LDX,NRHS)
The N by NRHS matrix X.
LDX
LDX is INTEGER
The leading dimension of the array X. LDX >= max(N,1).
BETA
BETA is DOUBLE PRECISION
The scalar beta. BETA must be 0., 1., or 1.; otherwise,
it is assumed to be 1.
B
B is DOUBLE PRECISION array, dimension (LDB,NRHS)
On entry, the N by NRHS matrix B.
On exit, B is overwritten by the matrix expression
B := alpha * A * X + beta * B.
LDB
LDB is INTEGER
The leading dimension of the array B. LDB >= max(N,1).
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Definition at line 145 of file dlagtm.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dlagtm.f(3) 
