org.netlib.lapack
Class Dlaqr1

java.lang.Object
  extended by org.netlib.lapack.Dlaqr1

public class Dlaqr1
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.

* .. * * Given a 2-by-2 or 3-by-3 matrix H, DLAQR1 sets v to a * scalar multiple of the first column of the product * * (*) K = (H - (sr1 + i*si1)*I)*(H - (sr2 + i*si2)*I) * * scaling to avoid overflows and most underflows. It * is assumed that either * * 1) sr1 = sr2 and si1 = -si2 * or * 2) si1 = si2 = 0. * * This is useful for starting double implicit shift bulges * in the QR algorithm. * * * N (input) integer * Order of the matrix H. N must be either 2 or 3. * * H (input) DOUBLE PRECISION array of dimension (LDH,N) * The 2-by-2 or 3-by-3 matrix H in (*). * * LDH (input) integer * The leading dimension of H as declared in * the calling procedure. LDH.GE.N * * SR1 (input) DOUBLE PRECISION * SI1 The shifts in (*). * SR2 * SI2 * * V (output) DOUBLE PRECISION array of dimension N * A scalar multiple of the first column of the * matrix K in (*). * * ================================================================ * Based on contributions by * Karen Braman and Ralph Byers, Department of Mathematics, * University of Kansas, USA * * ================================================================ * * .. Parameters ..


Constructor Summary
Dlaqr1()
           
 
Method Summary
static void dlaqr1(int n, double[] h, int _h_offset, int ldh, double sr1, double si1, double sr2, double si2, double[] v, int _v_offset)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Dlaqr1

public Dlaqr1()
Method Detail

dlaqr1

public static void dlaqr1(int n,
                          double[] h,
                          int _h_offset,
                          int ldh,
                          double sr1,
                          double si1,
                          double sr2,
                          double si2,
                          double[] v,
                          int _v_offset)