org.netlib.lapack
Class DGGBAK

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

public class DGGBAK
extends java.lang.Object

DGGBAK is a simplified interface to the JLAPACK routine dggbak.
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 * ======= * * DGGBAK forms the right or left eigenvectors of a real generalized * eigenvalue problem A*x = lambda*B*x, by backward transformation on * the computed eigenvectors of the balanced pair of matrices output by * DGGBAL. * * Arguments * ========= * * JOB (input) CHARACTER*1 * Specifies the type of backward transformation required: * = 'N': do nothing, return immediately; * = 'P': do backward transformation for permutation only; * = 'S': do backward transformation for scaling only; * = 'B': do backward transformations for both permutation and * scaling. * JOB must be the same as the argument JOB supplied to DGGBAL. * * SIDE (input) CHARACTER*1 * = 'R': V contains right eigenvectors; * = 'L': V contains left eigenvectors. * * N (input) INTEGER * The number of rows of the matrix V. N >= 0. * * ILO (input) INTEGER * IHI (input) INTEGER * The integers ILO and IHI determined by DGGBAL. * 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. * * LSCALE (input) DOUBLE PRECISION array, dimension (N) * Details of the permutations and/or scaling factors applied * to the left side of A and B, as returned by DGGBAL. * * RSCALE (input) DOUBLE PRECISION array, dimension (N) * Details of the permutations and/or scaling factors applied * to the right side of A and B, as returned by DGGBAL. * * M (input) INTEGER * The number of columns of the matrix V. M >= 0. * * V (input/output) DOUBLE PRECISION array, dimension (LDV,M) * On entry, the matrix of right or left eigenvectors to be * transformed, as returned by DTGEVC. * On exit, V is overwritten by the transformed eigenvectors. * * LDV (input) INTEGER * The leading dimension of the matrix V. LDV >= max(1,N). * * INFO (output) INTEGER * = 0: successful exit. * < 0: if INFO = -i, the i-th argument had an illegal value. * * Further Details * =============== * * See R.C. Ward, Balancing the generalized eigenvalue problem, * SIAM J. Sci. Stat. Comp. 2 (1981), 141-152. * * ===================================================================== * * .. Local Scalars ..


Constructor Summary
DGGBAK()
           
 
Method Summary
static void DGGBAK(java.lang.String job, java.lang.String side, int n, int ilo, int ihi, double[] lscale, double[] rscale, int m, double[][] v, intW info)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DGGBAK

public DGGBAK()
Method Detail

DGGBAK

public static void DGGBAK(java.lang.String job,
                          java.lang.String side,
                          int n,
                          int ilo,
                          int ihi,
                          double[] lscale,
                          double[] rscale,
                          int m,
                          double[][] v,
                          intW info)