org.netlib.lapack
Class SLAGV2

java.lang.Object
  extended by org.netlib.lapack.SLAGV2

public class SLAGV2
extends java.lang.Object

SLAGV2 is a simplified interface to the JLAPACK routine slagv2.
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 * ======= * * SLAGV2 computes the Generalized Schur factorization of a real 2-by-2 * matrix pencil (A,B) where B is upper triangular. This routine * computes orthogonal (rotation) matrices given by CSL, SNL and CSR, * SNR such that * * 1) if the pencil (A,B) has two real eigenvalues (include 0/0 or 1/0 * types), then * * [ a11 a12 ] := [ CSL SNL ] [ a11 a12 ] [ CSR -SNR ] * [ 0 a22 ] [ -SNL CSL ] [ a21 a22 ] [ SNR CSR ] * * [ b11 b12 ] := [ CSL SNL ] [ b11 b12 ] [ CSR -SNR ] * [ 0 b22 ] [ -SNL CSL ] [ 0 b22 ] [ SNR CSR ], * * 2) if the pencil (A,B) has a pair of complex conjugate eigenvalues, * then * * [ a11 a12 ] := [ CSL SNL ] [ a11 a12 ] [ CSR -SNR ] * [ a21 a22 ] [ -SNL CSL ] [ a21 a22 ] [ SNR CSR ] * * [ b11 0 ] := [ CSL SNL ] [ b11 b12 ] [ CSR -SNR ] * [ 0 b22 ] [ -SNL CSL ] [ 0 b22 ] [ SNR CSR ] * * where b11 >= b22 > 0. * * * Arguments * ========= * * A (input/output) REAL array, dimension (LDA, 2) * On entry, the 2 x 2 matrix A. * On exit, A is overwritten by the ``A-part'' of the * generalized Schur form. * * LDA (input) INTEGER * THe leading dimension of the array A. LDA >= 2. * * B (input/output) REAL array, dimension (LDB, 2) * On entry, the upper triangular 2 x 2 matrix B. * On exit, B is overwritten by the ``B-part'' of the * generalized Schur form. * * LDB (input) INTEGER * THe leading dimension of the array B. LDB >= 2. * * ALPHAR (output) REAL array, dimension (2) * ALPHAI (output) REAL array, dimension (2) * BETA (output) REAL array, dimension (2) * (ALPHAR(k)+i*ALPHAI(k))/BETA(k) are the eigenvalues of the * pencil (A,B), k=1,2, i = sqrt(-1). Note that BETA(k) may * be zero. * * CSL (output) REAL * The cosine of the left rotation matrix. * * SNL (output) REAL * The sine of the left rotation matrix. * * CSR (output) REAL * The cosine of the right rotation matrix. * * SNR (output) REAL * The sine of the right rotation matrix. * * Further Details * =============== * * Based on contributions by * Mark Fahey, Department of Mathematics, Univ. of Kentucky, USA * * ===================================================================== * * .. Parameters ..


Constructor Summary
SLAGV2()
           
 
Method Summary
static void SLAGV2(float[][] a, float[][] b, float[] alphar, float[] alphai, float[] beta, floatW csl, floatW snl, floatW csr, floatW snr)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SLAGV2

public SLAGV2()
Method Detail

SLAGV2

public static void SLAGV2(float[][] a,
                          float[][] b,
                          float[] alphar,
                          float[] alphai,
                          float[] beta,
                          floatW csl,
                          floatW snl,
                          floatW csr,
                          floatW snr)