SUBROUTINE DSYGV( ITYPE, JOBZ, UPLO, N, A, LDA, B, LDB, W, WORK, * LDWORK, INFO) CHARACTER * 1 JOBZ, UPLO INTEGER ITYPE, N, LDA, LDB, LDWORK, INFO DOUBLE PRECISION A(LDA,*), B(LDB,*), W(*), WORK(*) SUBROUTINE DSYGV_64( ITYPE, JOBZ, UPLO, N, A, LDA, B, LDB, W, WORK, * LDWORK, INFO) CHARACTER * 1 JOBZ, UPLO INTEGER*8 ITYPE, N, LDA, LDB, LDWORK, INFO DOUBLE PRECISION A(LDA,*), B(LDB,*), W(*), WORK(*)
SUBROUTINE SYGV( ITYPE, JOBZ, UPLO, N, A, [LDA], B, [LDB], W, [WORK], * [LDWORK], [INFO]) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER :: ITYPE, N, LDA, LDB, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A, B SUBROUTINE SYGV_64( ITYPE, JOBZ, UPLO, N, A, [LDA], B, [LDB], W, * [WORK], [LDWORK], [INFO]) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER(8) :: ITYPE, N, LDA, LDB, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A, B
void dsygv(int itype, char jobz, char uplo, int n, double *a, int lda, double *b, int ldb, double *w, int *info);
void dsygv_64(long itype, char jobz, char uplo, long n, double *a, long lda, double *b, long ldb, double *w, long *info);
positive definite.
On exit, if JOBZ = 'V', then if INFO = 0, A contains the matrix Z of eigenvectors. The eigenvectors are normalized as follows: if ITYPE = 1 or 2, Z**T*B*Z = I; if ITYPE = 3, Z**T*inv(B)*Z = I. If JOBZ = 'N', then on exit the upper triangle (if UPLO='U') or the lower triangle (if UPLO='L') of A, including the diagonal, is destroyed.
On exit, if INFO <= N, the part of B containing the matrix is overwritten by the triangular factor U or L from the Cholesky factorization B = U**T*U or B = L*L**T.
If LDWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LDWORK is issued by XERBLA.