claptm()

subroutine claptm	(	character	UPLO,
		integer	N,
		integer	NRHS,
		real	ALPHA,
		real, dimension( * )	D,
		complex, dimension( * )	E,
		complex, dimension( ldx, * )	X,
		integer	LDX,
		real	BETA,
		complex, dimension( ldb, * )	B,
		integer	LDB
	)

CLAPTM

Purpose:

 CLAPTM multiplies an N by NRHS matrix X by a Hermitian tridiagonal
 matrix A and stores the result in a matrix B.  The operation has the
 form

    B := alpha * A * X + beta * B

 where alpha may be either 1. or -1. and beta may be 0., 1., or -1.

Parameters

[in]	UPLO	UPLO is CHARACTER Specifies whether the superdiagonal or the subdiagonal of the tridiagonal matrix A is stored. = 'U': Upper, E is the superdiagonal of A. = 'L': Lower, E is the subdiagonal of A.
[in]	N	N is INTEGER The order of the matrix A. N >= 0.
[in]	NRHS	NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrices X and B.
[in]	ALPHA	ALPHA is REAL The scalar alpha. ALPHA must be 1. or -1.; otherwise, it is assumed to be 0.
[in]	D	D is REAL array, dimension (N) The n diagonal elements of the tridiagonal matrix A.
[in]	E	E is COMPLEX array, dimension (N-1) The (n-1) subdiagonal or superdiagonal elements of A.
[in]	X	X is COMPLEX array, dimension (LDX,NRHS) The N by NRHS matrix X.
[in]	LDX	LDX is INTEGER The leading dimension of the array X. LDX >= max(N,1).
[in]	BETA	BETA is REAL The scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 1.
[in,out]	B	B is COMPLEX 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.
[in]	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.