dsyev - compute all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A
SUBROUTINE DSYEV(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER*1 JOBZ, UPLO INTEGER N, LDA, LDWORK, INFO DOUBLE PRECISION A(LDA,*), W(*), WORK(*) SUBROUTINE DSYEV_64(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER*1 JOBZ, UPLO INTEGER*8 N, LDA, LDWORK, INFO DOUBLE PRECISION A(LDA,*), W(*), WORK(*) F95 INTERFACE SUBROUTINE SYEV(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER :: N, LDA, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A SUBROUTINE SYEV_64(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER(8) :: N, LDA, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void dsyev(char jobz, char uplo, int n, double *a, int lda, double *w, int *info); void dsyev_64(char jobz, char uplo, long n, double *a, long lda, double *w, long *info);
Oracle Solaris Studio Performance Library dsyev(3P) NAME dsyev - compute all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A SYNOPSIS SUBROUTINE DSYEV(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER*1 JOBZ, UPLO INTEGER N, LDA, LDWORK, INFO DOUBLE PRECISION A(LDA,*), W(*), WORK(*) SUBROUTINE DSYEV_64(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER*1 JOBZ, UPLO INTEGER*8 N, LDA, LDWORK, INFO DOUBLE PRECISION A(LDA,*), W(*), WORK(*) F95 INTERFACE SUBROUTINE SYEV(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER :: N, LDA, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A SUBROUTINE SYEV_64(JOBZ, UPLO, N, A, LDA, W, WORK, LDWORK, INFO) CHARACTER(LEN=1) :: JOBZ, UPLO INTEGER(8) :: N, LDA, LDWORK, INFO REAL(8), DIMENSION(:) :: W, WORK REAL(8), DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void dsyev(char jobz, char uplo, int n, double *a, int lda, double *w, int *info); void dsyev_64(char jobz, char uplo, long n, double *a, long lda, double *w, long *info); PURPOSE dsyev computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. ARGUMENTS JOBZ (input) = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. 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. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diago- nal, is destroyed. LDA (input) The leading dimension of the array A. LDA >= max(1,N). W (output) If INFO = 0, the eigenvalues in ascending order. WORK (workspace) On exit, if INFO = 0, WORK(1) returns the optimal LDWORK. LDWORK (input) The length of the array WORK. LDWORK >= max(1,3*N-1). For optimal efficiency, LDWORK >= (NB+2)*N, where NB is the blocksize for DSYTRD returned by ILAENV. If LDWORK = -1, then a workspace query is assumed; the rou- tine 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. INFO (output) = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, the algorithm failed to converge; i off- diagonal elements of an intermediate tridiagonal form did not converge to zero. 7 Nov 2015 dsyev(3P)