org.netlib.lapack
Class SLAIC1

java.lang.Object
  extended by org.netlib.lapack.SLAIC1

public class SLAIC1
extends java.lang.Object

SLAIC1 is a simplified interface to the JLAPACK routine slaic1.
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 * ======= * * SLAIC1 applies one step of incremental condition estimation in * its simplest version: * * Let x, twonorm(x) = 1, be an approximate singular vector of an j-by-j * lower triangular matrix L, such that * twonorm(L*x) = sest * Then SLAIC1 computes sestpr, s, c such that * the vector * [ s*x ] * xhat = [ c ] * is an approximate singular vector of * [ L 0 ] * Lhat = [ w' gamma ] * in the sense that * twonorm(Lhat*xhat) = sestpr. * * Depending on JOB, an estimate for the largest or smallest singular * value is computed. * * Note that [s c]' and sestpr**2 is an eigenpair of the system * * diag(sest*sest, 0) + [alpha gamma] * [ alpha ] * [ gamma ] * * where alpha = x'*w. * * Arguments * ========= * * JOB (input) INTEGER * = 1: an estimate for the largest singular value is computed. * = 2: an estimate for the smallest singular value is computed. * * J (input) INTEGER * Length of X and W * * X (input) REAL array, dimension (J) * The j-vector x. * * SEST (input) REAL * Estimated singular value of j by j matrix L * * W (input) REAL array, dimension (J) * The j-vector w. * * GAMMA (input) REAL * The diagonal element gamma. * * SESTPR (output) REAL * Estimated singular value of (j+1) by (j+1) matrix Lhat. * * S (output) REAL * Sine needed in forming xhat. * * C (output) REAL * Cosine needed in forming xhat. * * ===================================================================== * * .. Parameters ..


Constructor Summary
SLAIC1()
           
 
Method Summary
static void SLAIC1(int job, int j, float[] x, float sest, float[] w, float gamma, floatW sestpr, floatW s, floatW c)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SLAIC1

public SLAIC1()
Method Detail

SLAIC1

public static void SLAIC1(int job,
                          int j,
                          float[] x,
                          float sest,
                          float[] w,
                          float gamma,
                          floatW sestpr,
                          floatW s,
                          floatW c)