# 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

Univ. of Colorado Denver

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