p?potrf

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 4/28/2026

Version

Public

p?potrf

Computes the Cholesky factorization of a symmetric (Hermitian) positive-definite distributed matrix.

Syntax

call pspotrf ( uplo , n , a , ia , ja , desca , info )

call pdpotrf ( uplo , n , a , ia , ja , desca , info )

call pcpotrf ( uplo , n , a , ia , ja , desca , info )

call pzpotrf ( uplo , n , a , ia , ja , desca , info )

Include Files

mkl_scalapack.h

Description

pspotrf pdpotrf pcpotrf pzpotrf The p?potrf routine function computes the Cholesky factorization of a real symmetric or complex Hermitian positive-definite distributed n -by- n matrix A ( ia : ia + n -1, ja : ja + n -1), denoted below as sub( A ).

The factorization has the form

sub( A ) = U^:code:`H`*U if uplo='U' , or

sub( A ) = L*L^:code:`H` if uplo='L'

where L is a lower triangular matrix and U is upper triangular.

Input Parameters

uplo

(global) CHARACTER*1 .

Indicates whether the upper or lower triangular part of sub( A ) is stored. Must be ‘U’ or ‘L’ . If uplo = 'U' , the array a stores the upper triangular part of the matrix sub( A ) that is factored as U^:code:`H`*U .

n

(global) INTEGER . The order of the distributed matrix sub( A ) (n≥0) .

a

(local) REAL for pspotrf DOUBLE PRECISON for pdpotrf COMPLEX for pcpotrf DOUBLE COMPLEX for pzpotrf .

Pointer into the local memory to an array of size (lld_a, LOCc(ja+n-1)) .

On entry, this array contains the local pieces of the n -by- n symmetric/Hermitian distributed matrix sub( A ) to be factored. Depending on uplo , the array a contains either the upper or the lower triangular part of the matrix sub( A ) (see uplo ).

ia , ja

(global) INTEGER . The row and column indices in the global matrix A indicating the first row and the first column of the matrix sub( A ), respectively.

desca

(global and local) INTEGER array of size dlen_ . The array descriptor for the distributed matrix A .

Output Parameters

a

The upper or lower triangular part of a is overwritten by the Cholesky factor U or L , as specified by uplo .

info

(global) INTEGER . If info=0 , the execution is successful;

info < 0 : if the i -th argument is an array, and the j- th entry had an illegal value, then info = -( i *100+ j ); if the i- th argument is a scalar and had an illegal value, then info = -i .

If info = k >0, the leading minor of order k , A ( ia : ia + k -1, ja : ja + k -1), is not positive-definite, and the factorization could not be completed.

NOTE:

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

p?potrf

Syntax

Include Files

Description

Input Parameters

Output Parameters