SUBROUTINE ZPBTF2( UPLO, N, KD, AB, LDAB, INFO) CHARACTER * 1 UPLO DOUBLE COMPLEX AB(LDAB,*) INTEGER N, KD, LDAB, INFO SUBROUTINE ZPBTF2_64( UPLO, N, KD, AB, LDAB, INFO) CHARACTER * 1 UPLO DOUBLE COMPLEX AB(LDAB,*) INTEGER*8 N, KD, LDAB, INFO
SUBROUTINE PBTF2( UPLO, [N], KD, AB, [LDAB], [INFO]) CHARACTER(LEN=1) :: UPLO COMPLEX(8), DIMENSION(:,:) :: AB INTEGER :: N, KD, LDAB, INFO SUBROUTINE PBTF2_64( UPLO, [N], KD, AB, [LDAB], [INFO]) CHARACTER(LEN=1) :: UPLO COMPLEX(8), DIMENSION(:,:) :: AB INTEGER(8) :: N, KD, LDAB, INFO
void zpbtf2(char uplo, int n, int kd, doublecomplex *ab, int ldab, int *info);
void zpbtf2_64(char uplo, long n, long kd, doublecomplex *ab, long ldab, long *info);
The factorization has the form
A = U' * U , if UPLO = 'U', or A = L * L', if UPLO = 'L',
where U is an upper triangular matrix, U' is the conjugate transpose of U, and L is lower triangular.
This is the unblocked version of the algorithm, calling Level 2 BLAS.
On exit, if INFO = 0, the triangular factor U or L from the Cholesky factorization A = U'*U or A = L*L' of the band matrix A, in the same storage format as A.