public class SSYEVD
- extends java.lang.Object
SSYEVD is a simplified interface to the JLAPACK routine ssyevd.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines. Using this interface also allows you
to omit offset and leading dimension arguments. However, because
of these conversions, these routines will be slower than the low
level ones. Following is the description from the original Fortran
source. Contact firstname.lastname@example.org with any questions.
* SSYEVD computes all eigenvalues and, optionally, eigenvectors of a
* real symmetric matrix A. If eigenvectors are desired, it uses a
* divide and conquer algorithm.
* The divide and conquer algorithm makes very mild assumptions about
* floating point arithmetic. It will work on machines with a guard
* digit in add/subtract, or on those binary machines without guard
* digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or
* Cray-2. It could conceivably fail on hexadecimal or decimal machines
* without guard digits, but we know of none.
* Because of large use of BLAS of level 3, SSYEVD needs N**2 more
* workspace than SSYEVX.
* JOBZ (input) CHARACTER*1
* = 'N': Compute eigenvalues only;
* = 'V': Compute eigenvalues and eigenvectors.
* UPLO (input) CHARACTER*1
* = 'U': Upper triangle of A is stored;
* = 'L': Lower triangle of A is stored.
* N (input) INTEGER
* The order of the matrix A. N >= 0.
* A (input/output) REAL array, dimension (LDA, N)
* On entry, the symmetric matrix A. If UPLO = 'U', the
* leading N-by-N upper triangular part of A contains the
* upper triangular 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
* diagonal, is destroyed.
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,N).
* W (output) REAL array, dimension (N)
* If INFO = 0, the eigenvalues in ascending order.
* WORK (workspace/output) REAL array,
* dimension (LWORK)
* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
* LWORK (input) INTEGER
* The dimension of the array WORK.
* If N <= 1, LWORK must be at least 1.
* If JOBZ = 'N' and N > 1, LWORK must be at least 2*N+1.
* If JOBZ = 'V' and N > 1, LWORK must be at least
* 1 + 6*N + 2*N**2.
* If LWORK = -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 LWORK is issued by XERBLA.
* IWORK (workspace/output) INTEGER array, dimension (LIWORK)
* On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK.
* LIWORK (input) INTEGER
* The dimension of the array IWORK.
* If N <= 1, LIWORK must be at least 1.
* If JOBZ = 'N' and N > 1, LIWORK must be at least 1.
* If JOBZ = 'V' and N > 1, LIWORK must be at least 3 + 5*N.
* If LIWORK = -1, then a workspace query is assumed; the
* routine only calculates the optimal size of the IWORK array,
* returns this value as the first entry of the IWORK array, and
* no error message related to LIWORK is issued by XERBLA.
* INFO (output) INTEGER
* = 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.
* Further Details
* Based on contributions by
* Jeff Rutter, Computer Science Division, University of California
* at Berkeley, USA
* Modified by Francoise Tisseur, University of Tennessee.
* .. Parameters ..
|Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
public static void SSYEVD(java.lang.String jobz,