# CentOS 7.0 - man page for dlagtm (centos section 3)

dlagtm.f(3) LAPACK dlagtm.f(3)dlagtm.fNAME-Functions/Subroutines subroutine dlagtm (TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB) DLAGTM performs a matrix-matrix 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, orSYNOPSIS-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 matrix-matrix 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, orPurpose: DLAGTM performs a matrix-vector 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 (N-1) The (n-1) sub-diagonal elements of T. D D is DOUBLE PRECISION array, dimension (N) The diagonal elements of T. DU DU is DOUBLE PRECISION array, dimension (N-1) The (n-1) super-diagonal 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.-1.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 dlagtm.f(3)