# claptm.f - Man Page

TESTING/LIN/claptm.f

## Synopsis

### Functions/Subroutines

subroutine **claptm** (uplo, n, nrhs, alpha, d, e, x, ldx, beta, b, ldb)**CLAPTM**

## Function/Subroutine Documentation

### 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***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.

*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 REAL The scalar alpha. ALPHA must be 1. or -1.; otherwise, it is assumed to be 0.

*D*D is REAL array, dimension (N) The n diagonal elements of the tridiagonal matrix A.

*E*E is COMPLEX array, dimension (N-1) The (n-1) subdiagonal or superdiagonal elements of A.

*X*X is COMPLEX 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 REAL The scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 1.

*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.

*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.

Definition at line **127** of file **claptm.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page claptm(3) is an alias of claptm.f(3).

Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK