# cppt02.f - Man Page

TESTING/LIN/cppt02.f

## Synopsis

### Functions/Subroutines

subroutine cppt02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)
CPPT02

## Function/Subroutine Documentation

### subroutine cppt02 (character uplo, integer n, integer nrhs, complex, dimension( * ) a, complex, dimension( ldx, * ) x, integer ldx, complex, dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real resid)

CPPT02

Purpose:

``` CPPT02 computes the residual in the solution of a Hermitian system
of linear equations  A*x = b  when packed storage is used for the
coefficient matrix.  The ratio computed is

RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS),

where EPS is the machine precision.```
Parameters

UPLO

```          UPLO is CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored:
= 'U':  Upper triangular
= 'L':  Lower triangular```

N

```          N is INTEGER
The number of rows and columns of the matrix A.  N >= 0.```

NRHS

```          NRHS is INTEGER
The number of columns of B, the matrix of right hand sides.
NRHS >= 0.```

A

```          A is COMPLEX array, dimension (N*(N+1)/2)
The original Hermitian matrix A, stored as a packed
triangular matrix.```

X

```          X is COMPLEX array, dimension (LDX,NRHS)
The computed solution vectors for the system of linear
equations.```

LDX

```          LDX is INTEGER
The leading dimension of the array X.   LDX >= max(1,N).```

B

```          B is COMPLEX array, dimension (LDB,NRHS)
On entry, the right hand side vectors for the system of
linear equations.
On exit, B is overwritten with the difference B - A*X.```

LDB

```          LDB is INTEGER
The leading dimension of the array B.  LDB >= max(1,N).```

RWORK

`          RWORK is REAL array, dimension (N)`

RESID

```          RESID is REAL
The maximum over the number of right hand sides of
norm(B - A*X) / ( norm(A) * norm(X) * EPS ).```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 121 of file cppt02.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page cppt02(3) is an alias of cppt02.f(3).

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