org.netlib.lapack
Class SLASD8
java.lang.Object
org.netlib.lapack.SLASD8
public class SLASD8
- extends java.lang.Object
SLASD8 is a simplified interface to the JLAPACK routine slasd8.
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
* =======
*
* SLASD8 finds the square roots of the roots of the secular equation,
* as defined by the values in DSIGMA and Z. It makes the appropriate
* calls to SLASD4, and stores, for each element in D, the distance
* to its two nearest poles (elements in DSIGMA). It also updates
* the arrays VF and VL, the first and last components of all the
* right singular vectors of the original bidiagonal matrix.
*
* SLASD8 is called from SLASD6.
*
* Arguments
* =========
*
* ICOMPQ (input) INTEGER
* Specifies whether singular vectors are to be computed in
* factored form in the calling routine:
* = 0: Compute singular values only.
* = 1: Compute singular vectors in factored form as well.
*
* K (input) INTEGER
* The number of terms in the rational function to be solved
* by SLASD4. K >= 1.
*
* D (output) REAL array, dimension ( K )
* On output, D contains the updated singular values.
*
* Z (input) REAL array, dimension ( K )
* The first K elements of this array contain the components
* of the deflation-adjusted updating row vector.
*
* VF (input/output) REAL array, dimension ( K )
* On entry, VF contains information passed through DBEDE8.
* On exit, VF contains the first K components of the first
* components of all right singular vectors of the bidiagonal
* matrix.
*
* VL (input/output) REAL array, dimension ( K )
* On entry, VL contains information passed through DBEDE8.
* On exit, VL contains the first K components of the last
* components of all right singular vectors of the bidiagonal
* matrix.
*
* DIFL (output) REAL array, dimension ( K )
* On exit, DIFL(I) = D(I) - DSIGMA(I).
*
* DIFR (output) REAL array,
* dimension ( LDDIFR, 2 ) if ICOMPQ = 1 and
* dimension ( K ) if ICOMPQ = 0.
* On exit, DIFR(I,1) = D(I) - DSIGMA(I+1), DIFR(K,1) is not
* defined and will not be referenced.
*
* If ICOMPQ = 1, DIFR(1:K,2) is an array containing the
* normalizing factors for the right singular vector matrix.
*
* LDDIFR (input) INTEGER
* The leading dimension of DIFR, must be at least K.
*
* DSIGMA (input) REAL array, dimension ( K )
* The first K elements of this array contain the old roots
* of the deflated updating problem. These are the poles
* of the secular equation.
*
* WORK (workspace) REAL array, dimension at least 3 * K
*
* INFO (output) INTEGER
* = 0: successful exit.
* < 0: if INFO = -i, the i-th argument had an illegal value.
* > 0: if INFO = 1, an singular value did not converge
*
* Further Details
* ===============
*
* Based on contributions by
* Ming Gu and Huan Ren, Computer Science Division, University of
* California at Berkeley, USA
*
* =====================================================================
*
* .. Parameters ..
|
Method Summary |
static void |
SLASD8(int icompq,
int k,
float[] d,
float[] z,
float[] vf,
float[] vl,
float[] difl,
float[][] difr,
float[] dsigma,
float[] work,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SLASD8
public SLASD8()
SLASD8
public static void SLASD8(int icompq,
int k,
float[] d,
float[] z,
float[] vf,
float[] vl,
float[] difl,
float[][] difr,
float[] dsigma,
float[] work,
intW info)