# zpot01.f - Man Page

TESTING/LIN/zpot01.f

## Synopsis

### Functions/Subroutines

subroutine zpot01 (uplo, n, a, lda, afac, ldafac, rwork, resid)
ZPOT01

## Function/Subroutine Documentation

### subroutine zpot01 (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldafac, * ) afac, integer ldafac, double precision, dimension( * ) rwork, double precision resid)

ZPOT01

Purpose:

``` ZPOT01 reconstructs a Hermitian positive definite 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*16 array, dimension (LDA,N)
The original Hermitian matrix A.```

LDA

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

AFAC

```          AFAC is COMPLEX*16 array, dimension (LDAFAC,N)
On entry, the factor L or U from the L * L**H or U**H * U
factorization of A.
Overwritten with the reconstructed matrix, and then with
the difference L * L**H - A (or U**H * U - A).```

LDAFAC

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

RWORK

`          RWORK is DOUBLE PRECISION array, dimension (N)`

RESID

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

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 105 of file zpot01.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page zpot01(3) is an alias of zpot01.f(3).

Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK