# 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

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