CXML
        	    
LAPACK version 3.0
dlagtm(3)

PURPOSE
  DLAGTM - perform 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

SYNTAX
  SUBROUTINE DLAGTM( TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB )

      CHARACTER	     TRANS

      INTEGER	     LDB, LDX, N, NRHS

      DOUBLE	     PRECISION ALPHA, BETA

      DOUBLE	     PRECISION B( LDB, * ), D( * ), DL( * ), DU( * ), X( LDX,
		     * )

DESCRIPTION
  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.

ARGUMENTS
  TRANS	  (input) CHARACTER
	  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	  (input) INTEGER
	  The order of the matrix A.  N >= 0.

  NRHS	  (input) INTEGER
	  The number of right hand sides, i.e., the number of columns of the
	  matrices X and B.

  ALPHA	  (input) DOUBLE PRECISION
	  The scalar alpha.  ALPHA must be 0., 1., or -1.; otherwise, it is
	  assumed to be 0.

  DL	  (input) DOUBLE PRECISION array, dimension (N-1)
	  The (n-1) sub-diagonal elements of T.

  D	  (input) DOUBLE PRECISION array, dimension (N)
	  The diagonal elements of T.

  DU	  (input) DOUBLE PRECISION array, dimension (N-1)
	  The (n-1) super-diagonal elements of T.

  X	  (input) DOUBLE PRECISION array, dimension (LDX,NRHS)
	  The N by NRHS matrix X.  LDX	   (input) INTEGER The leading
	  dimension of the array X.  LDX >= max(N,1).

  BETA	  (input) DOUBLE PRECISION
	  The scalar beta.  BETA must be 0., 1., or -1.; otherwise, it is
	  assumed to be 1.

  B	  (input/output) 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	  (input) INTEGER
	  The leading dimension of the array B.	 LDB >= max(N,1).