SUBROUTINE ZPOSV( UPLO, N, NRHS, A, LDA, B, LDB, INFO) CHARACTER * 1 UPLO DOUBLE COMPLEX A(LDA,*), B(LDB,*) INTEGER N, NRHS, LDA, LDB, INFO SUBROUTINE ZPOSV_64( UPLO, N, NRHS, A, LDA, B, LDB, INFO) CHARACTER * 1 UPLO DOUBLE COMPLEX A(LDA,*), B(LDB,*) INTEGER*8 N, NRHS, LDA, LDB, INFO
SUBROUTINE POSV( UPLO, [N], [NRHS], A, [LDA], B, [LDB], [INFO]) CHARACTER(LEN=1) :: UPLO COMPLEX(8), DIMENSION(:,:) :: A, B INTEGER :: N, NRHS, LDA, LDB, INFO SUBROUTINE POSV_64( UPLO, [N], [NRHS], A, [LDA], B, [LDB], [INFO]) CHARACTER(LEN=1) :: UPLO COMPLEX(8), DIMENSION(:,:) :: A, B INTEGER(8) :: N, NRHS, LDA, LDB, INFO
void zposv(char uplo, int n, int nrhs, doublecomplex *a, int lda, doublecomplex *b, int ldb, int *info);
void zposv_64(char uplo, long n, long nrhs, doublecomplex *a, long lda, doublecomplex *b, long ldb, long *info);
The Cholesky decomposition is used to factor A as
A = U**H* U, if UPLO = 'U', or A = L * L**H, if UPLO = 'L',
where U is an upper triangular matrix and L is a lower triangular matrix. The factored form of A is then used to solve the system of equations A * X = B.
On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H.