org.netlib.lapack
Class Dlaqr1
java.lang.Object
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 ..
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 |
Dlaqr1
public Dlaqr1()
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)