org.netlib.lapack
Class Dlarrj
java.lang.Object
org.netlib.lapack.Dlarrj
public class Dlarrj
- extends java.lang.Object
Following is the description from the original
Fortran source. For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.
* ..
*
* Purpose
* =======
*
* Given the initial eigenvalue approximations of T, DLARRJ
* does bisection to refine the eigenvalues of T,
* W( IFIRST-OFFSET ) through W( ILAST-OFFSET ), to more accuracy. Initi
* guesses for these eigenvalues are input in W, the corresponding estim
* of the error in these guesses in WERR. During bisection, intervals
* [left, right] are maintained by storing their mid-points and
* semi-widths in the arrays W and WERR respectively.
*
* Arguments
* =========
*
* N (input) INTEGER
* The order of the matrix.
*
* D (input) DOUBLE PRECISION array, dimension (N)
* The N diagonal elements of T.
*
* E2 (input) DOUBLE PRECISION array, dimension (N-1)
* The Squares of the (N-1) subdiagonal elements of T.
*
* IFIRST (input) INTEGER
* The index of the first eigenvalue to be computed.
*
* ILAST (input) INTEGER
* The index of the last eigenvalue to be computed.
*
* RTOL (input) DOUBLE PRECISION
* Tolerance for the convergence of the bisection intervals.
* An interval [LEFT,RIGHT] has converged if
* RIGHT-LEFT.LT.RTOL*MAX(|LEFT|,|RIGHT|).
*
* OFFSET (input) INTEGER
* Offset for the arrays W and WERR, i.e., the IFIRST-OFFSET
* through ILAST-OFFSET elements of these arrays are to be used.
*
* W (input/output) DOUBLE PRECISION array, dimension (N)
* On input, W( IFIRST-OFFSET ) through W( ILAST-OFFSET ) are
* estimates of the eigenvalues of L D L^T indexed IFIRST throug
* ILAST.
* On output, these estimates are refined.
*
* WERR (input/output) DOUBLE PRECISION array, dimension (N)
* On input, WERR( IFIRST-OFFSET ) through WERR( ILAST-OFFSET )
* the errors in the estimates of the corresponding elements in
* On output, these errors are refined.
*
* WORK (workspace) DOUBLE PRECISION array, dimension (2*N)
* Workspace.
*
* IWORK (workspace) INTEGER array, dimension (2*N)
* Workspace.
*
* PIVMIN (input) DOUBLE PRECISION
* The minimum pivot in the Sturm sequence for T.
*
* SPDIAM (input) DOUBLE PRECISION
* The spectral diameter of T.
*
* INFO (output) INTEGER
* Error flag.
*
* Further Details
* ===============
*
* Based on contributions by
* Beresford Parlett, University of California, Berkeley, USA
* Jim Demmel, University of California, Berkeley, USA
* Inderjit Dhillon, University of Texas, Austin, USA
* Osni Marques, LBNL/NERSC, USA
* Christof Voemel, University of California, Berkeley, USA
*
* =====================================================================
*
* .. Parameters ..
Method Summary |
static void |
dlarrj(int n,
double[] d,
int _d_offset,
double[] e2,
int _e2_offset,
int ifirst,
int ilast,
double rtol,
int offset,
double[] w,
int _w_offset,
double[] werr,
int _werr_offset,
double[] work,
int _work_offset,
int[] iwork,
int _iwork_offset,
double pivmin,
double spdiam,
intW info)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Dlarrj
public Dlarrj()
dlarrj
public static void dlarrj(int n,
double[] d,
int _d_offset,
double[] e2,
int _e2_offset,
int ifirst,
int ilast,
double rtol,
int offset,
double[] w,
int _w_offset,
double[] werr,
int _werr_offset,
double[] work,
int _work_offset,
int[] iwork,
int _iwork_offset,
double pivmin,
double spdiam,
intW info)