org.netlib.lapack
Class Dlanv2

java.lang.Object
  org.netlib.lapack.Dlanv2

public class Dlanv2
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
 *  =======
 *
 *  DLANV2 computes the Schur factorization of a real 2-by-2 nonsymmetric
 *  matrix in standard form:
 *
 *       [ A  B ] = [ CS -SN ] [ AA  BB ] [ CS  SN ]
 *       [ C  D ]   [ SN  CS ] [ CC  DD ] [-SN  CS ]
 *
 *  where either
 *  1) CC = 0 so that AA and DD are real eigenvalues of the matrix, or
 *  2) AA = DD and BB*CC < 0, so that AA + or - sqrt(BB*CC) are complex
 *  conjugate eigenvalues.
 *
 *  Arguments
 *  =========
 *
 *  A       (input/output) DOUBLE PRECISION
 *  B       (input/output) DOUBLE PRECISION
 *  C       (input/output) DOUBLE PRECISION
 *  D       (input/output) DOUBLE PRECISION
 *          On entry, the elements of the input matrix.
 *          On exit, they are overwritten by the elements of the
 *          standardised Schur form.
 *
 *  RT1R    (output) DOUBLE PRECISION
 *  RT1I    (output) DOUBLE PRECISION
 *  RT2R    (output) DOUBLE PRECISION
 *  RT2I    (output) DOUBLE PRECISION
 *          The real and imaginary parts of the eigenvalues. If the
 *          eigenvalues are a complex conjugate pair, RT1I > 0.
 *
 *  CS      (output) DOUBLE PRECISION
 *  SN      (output) DOUBLE PRECISION
 *          Parameters of the rotation matrix.
 *
 *  Further Details
 *  ===============
 *
 *  Modified by V. Sima, Research Institute for Informatics, Bucharest,
 *  Romania, to reduce the risk of cancellation errors,
 *  when computing real eigenvalues, and to ensure, if possible, that
 *  abs(RT1R) >= abs(RT2R).
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dlanv2()

Method Summary

static void

dlanv2(doubleW a, doubleW b, doubleW c, doubleW d, doubleW rt1r, doubleW rt1i, doubleW rt2r, doubleW rt2i, doubleW cs, doubleW sn)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Dlanv2

public Dlanv2()

Method Detail

dlanv2

public static void dlanv2(doubleW a,
                          doubleW b,
                          doubleW c,
                          doubleW d,
                          doubleW rt1r,
                          doubleW rt1i,
                          doubleW rt2r,
                          doubleW rt2i,
                          doubleW cs,
                          doubleW sn)