# dpotf2.f - Man Page

## Synopsis

### Functions/Subroutines

subroutine **dpotf2** (UPLO, **N**, A, **LDA**, INFO)**DPOTF2** computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblocked algorithm).

## Function/Subroutine Documentation

### subroutine dpotf2 (character UPLO, integer N, double precision, dimension( lda, * ) A, integer LDA, integer INFO)

**DPOTF2** computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblocked algorithm).

**Purpose:**

DPOTF2 computes the Cholesky factorization of a real symmetric positive definite matrix A. The factorization has the form A = U**T * U , if UPLO = 'U', or A = L * L**T, if UPLO = 'L', where U is an upper triangular matrix and L is lower triangular. This is the unblocked version of the algorithm, calling Level 2 BLAS.

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

*N*N is INTEGER The order of the matrix A. N >= 0.

*A*A is DOUBLE PRECISION array, dimension (LDA,N) On entry, the symmetric matrix A. If UPLO = 'U', the leading n by n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U**T *U or A = L*L**T.

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

*INFO*INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value > 0: if INFO = k, the leading minor of order k is not positive definite, and the factorization could not be completed.

**Author:**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**December 2016

Definition at line 111 of file dpotf2.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dpotf2(3) is an alias of dpotf2.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK