org.netlib.lapack
Class SGGBAK
java.lang.Object
org.netlib.lapack.SGGBAK
public class SGGBAK
- extends java.lang.Object
SGGBAK is a simplified interface to the JLAPACK routine sggbak.
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
* =======
*
* SGGBAK 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
* SGGBAL.
*
* 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 SGGBAL.
*
* 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 SGGBAL.
* 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
*
* LSCALE (input) REAL array, dimension (N)
* Details of the permutations and/or scaling factors applied
* to the left side of A and B, as returned by SGGBAL.
*
* RSCALE (input) REAL array, dimension (N)
* Details of the permutations and/or scaling factors applied
* to the right side of A and B, as returned by SGGBAL.
*
* M (input) INTEGER
* The number of columns of the matrix V. M >= 0.
*
* V (input/output) REAL array, dimension (LDV,M)
* On entry, the matrix of right or left eigenvectors to be
* transformed, as returned by STGEVC.
* 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 ..
Method Summary |
static void |
SGGBAK(java.lang.String job,
java.lang.String side,
int n,
int ilo,
int ihi,
float[] lscale,
float[] rscale,
int m,
float[][] v,
intW info)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SGGBAK
public SGGBAK()
SGGBAK
public static void SGGBAK(java.lang.String job,
java.lang.String side,
int n,
int ilo,
int ihi,
float[] lscale,
float[] rscale,
int m,
float[][] v,
intW info)