org.netlib.lapack
Class SLAED0
java.lang.Object
org.netlib.lapack.SLAED0
public class SLAED0
- extends java.lang.Object
SLAED0 is a simplified interface to the JLAPACK routine slaed0.
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 seymour@cs.utk.edu with any questions.
* ..
*
* Purpose
* =======
*
* SLAED0 computes all eigenvalues and corresponding eigenvectors of a
* symmetric tridiagonal matrix using the divide and conquer method.
*
* Arguments
* =========
*
* ICOMPQ (input) INTEGER
* = 0: Compute eigenvalues only.
* = 1: Compute eigenvectors of original dense symmetric matrix
* also. On entry, Q contains the orthogonal matrix used
* to reduce the original matrix to tridiagonal form.
* = 2: Compute eigenvalues and eigenvectors of tridiagonal
* matrix.
*
* QSIZ (input) INTEGER
* The dimension of the orthogonal matrix used to reduce
* the full matrix to tridiagonal form. QSIZ >= N if ICOMPQ = 1.
*
* N (input) INTEGER
* The dimension of the symmetric tridiagonal matrix. N >= 0.
*
* D (input/output) REAL array, dimension (N)
* On entry, the main diagonal of the tridiagonal matrix.
* On exit, its eigenvalues.
*
* E (input) REAL array, dimension (N-1)
* The off-diagonal elements of the tridiagonal matrix.
* On exit, E has been destroyed.
*
* Q (input/output) REAL array, dimension (LDQ, N)
* On entry, Q must contain an N-by-N orthogonal matrix.
* If ICOMPQ = 0 Q is not referenced.
* If ICOMPQ = 1 On entry, Q is a subset of the columns of the
* orthogonal matrix used to reduce the full
* matrix to tridiagonal form corresponding to
* the subset of the full matrix which is being
* decomposed at this time.
* If ICOMPQ = 2 On entry, Q will be the identity matrix.
* On exit, Q contains the eigenvectors of the
* tridiagonal matrix.
*
* LDQ (input) INTEGER
* The leading dimension of the array Q. If eigenvectors are
* desired, then LDQ >= max(1,N). In any case, LDQ >= 1.
*
* QSTORE (workspace) REAL array, dimension (LDQS, N)
* Referenced only when ICOMPQ = 1. Used to store parts of
* the eigenvector matrix when the updating matrix multiplies
* take place.
*
* LDQS (input) INTEGER
* The leading dimension of the array QSTORE. If ICOMPQ = 1,
* then LDQS >= max(1,N). In any case, LDQS >= 1.
*
* WORK (workspace) REAL array,
* If ICOMPQ = 0 or 1, the dimension of WORK must be at least
* 1 + 3*N + 2*N*lg N + 2*N**2
* ( lg( N ) = smallest integer k
* such that 2^k >= N )
* If ICOMPQ = 2, the dimension of WORK must be at least
* 4*N + N**2.
*
* IWORK (workspace) INTEGER array,
* If ICOMPQ = 0 or 1, the dimension of IWORK must be at least
* 6 + 6*N + 5*N*lg N.
* ( lg( N ) = smallest integer k
* such that 2^k >= N )
* If ICOMPQ = 2, the dimension of IWORK must be at least
* 3 + 5*N.
*
* INFO (output) INTEGER
* = 0: successful exit.
* < 0: if INFO = -i, the i-th argument had an illegal value.
* > 0: The algorithm failed to compute an eigenvalue while
* working on the submatrix lying in rows and columns
* INFO/(N+1) through mod(INFO,N+1).
*
* Further Details
* ===============
*
* Based on contributions by
* Jeff Rutter, Computer Science Division, University of California
* at Berkeley, USA
*
* =====================================================================
*
* .. Parameters ..
|
Method Summary |
static void |
SLAED0(int icompq,
int qsiz,
int n,
float[] d,
float[] e,
float[][] q,
float[][] qstore,
float[] work,
int[] iwork,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SLAED0
public SLAED0()
SLAED0
public static void SLAED0(int icompq,
int qsiz,
int n,
float[] d,
float[] e,
float[][] q,
float[][] qstore,
float[] work,
int[] iwork,
intW info)