# cppt01.f - Man Page

TESTING/LIN/cppt01.f

## Synopsis

### Functions/Subroutines

subroutine cppt01 (uplo, n, a, afac, rwork, resid)
CPPT01

## Function/Subroutine Documentation

### subroutine cppt01 (character uplo, integer n, complex, dimension( * ) a, complex, dimension( * ) afac, real, dimension( * ) rwork, real resid)

CPPT01

Purpose:

``` CPPT01 reconstructs a Hermitian positive definite packed matrix A
from its L*L' or U'*U factorization and computes the residual
norm( L*L' - A ) / ( N * norm(A) * EPS ) or
norm( U'*U - A ) / ( N * norm(A) * EPS ),
where EPS is the machine epsilon, L' is the conjugate transpose of
L, and U' is the conjugate transpose of U.```
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.```

A

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

AFAC

```          AFAC is COMPLEX array, dimension (N*(N+1)/2)
On entry, the factor L or U from the L*L' or U'*U
factorization of A, stored as a packed triangular matrix.
Overwritten with the reconstructed matrix, and then with the
difference L*L' - A (or U'*U - A).```

RWORK

`          RWORK is REAL array, dimension (N)`

RESID

```          RESID is REAL
If UPLO = 'L', norm(L*L' - A) / ( N * norm(A) * EPS )
If UPLO = 'U', norm(U'*U - A) / ( N * norm(A) * EPS )```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 94 of file cppt01.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page cppt01(3) is an alias of cppt01.f(3).

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