spotrf (3p)

Name

spotrf - tive definite matrix A

Synopsis

SUBROUTINE SPOTRF(UPLO, N, A, LDA, INFO)

CHARACTER*1 UPLO
INTEGER N, LDA, INFO
REAL A(LDA,*)

SUBROUTINE SPOTRF_64(UPLO, N, A, LDA, INFO)

CHARACTER*1 UPLO
INTEGER*8 N, LDA, INFO
REAL A(LDA,*)




F95 INTERFACE
SUBROUTINE POTRF(UPLO, N, A, LDA, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A

SUBROUTINE POTRF_64(UPLO, N, A, LDA, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDA, INFO
REAL, DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void spotrf(char uplo, int n, float *a, int lda, int *info);

void spotrf_64(char uplo, long n, float *a, long lda, long *info);

Description

Oracle Solaris Studio Performance Library                           spotrf(3P)



NAME
       spotrf  -  compute the Cholesky factorization of a real symmetric posi-
       tive definite matrix A


SYNOPSIS
       SUBROUTINE SPOTRF(UPLO, N, A, LDA, INFO)

       CHARACTER*1 UPLO
       INTEGER N, LDA, INFO
       REAL A(LDA,*)

       SUBROUTINE SPOTRF_64(UPLO, N, A, LDA, INFO)

       CHARACTER*1 UPLO
       INTEGER*8 N, LDA, INFO
       REAL A(LDA,*)




   F95 INTERFACE
       SUBROUTINE POTRF(UPLO, N, A, LDA, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER :: N, LDA, INFO
       REAL, DIMENSION(:,:) :: A

       SUBROUTINE POTRF_64(UPLO, N, A, LDA, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, LDA, INFO
       REAL, DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void spotrf(char uplo, int n, float *a, int lda, int *info);

       void spotrf_64(char uplo, long n, float *a, long lda, long *info);



PURPOSE
       spotrf 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 block version of the algorithm, calling Level 3 BLAS.


ARGUMENTS
       UPLO (input)
                 = 'U':  Upper triangle of A is stored;
                 = 'L':  Lower triangle of A is stored.


       N (input) The order of the matrix A.  N >= 0.


       A (input/output)
                 On entry, the symmetric matrix A.  If UPLO = 'U', the leading
                 N-by-N upper triangular part of A contains the upper triangu-
                 lar  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 (input)
                 The leading dimension of the array A.  LDA >= max(1,N).


       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value
                 > 0:  if INFO = i, the leading minor of order i is not  posi-
                 tive  definite, and the factorization could not be completed.




                                  7 Nov 2015                        spotrf(3P)