# 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

Univ. of Colorado Denver

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