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Class org.netlib.lapack.DSBGV

java.lang.Object
   |
   +----org.netlib.lapack.DSBGV

public class DSBGV

extends Object

DSBGV is a simplified interface to the JLAPACK routine dsbgv.
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
 *  =======
 *
 *  DSBGV computes all the eigenvalues, and optionally, the eigenvectors
 *  of a real generalized symmetric-definite banded eigenproblem, of
 *  the form A*x=(lambda)*B*x. Here A and B are assumed to be symmetric
 *  and banded, and B is also positive definite.
 *
 *  Arguments
 *  =========
 *
 *  JOBZ    (input) CHARACTER*1
 *          = 'N':  Compute eigenvalues only;
 *          = 'V':  Compute eigenvalues and eigenvectors.
 *
 *  UPLO    (input) CHARACTER*1
 *          = 'U':  Upper triangles of A and B are stored;
 *          = 'L':  Lower triangles of A and B are stored.
 *
 *  N       (input) INTEGER
 *          The order of the matrices A and B.  N >= 0.
 *
 *  KA      (input) INTEGER
 *          The number of superdiagonals of the matrix A if UPLO = 'U',
 *          or the number of subdiagonals if UPLO = 'L'. KA >= 0.
 *
 *  KB      (input) INTEGER
 *          The number of superdiagonals of the matrix B if UPLO = 'U',
 *          or the number of subdiagonals if UPLO = 'L'. KB >= 0.
 *
 *  AB      (input/output) DOUBLE PRECISION array, dimension (LDAB, N)
 *          On entry, the upper or lower triangle of the symmetric band
 *          matrix A, stored in the first ka+1 rows of the array.  The
 *          j-th column of A is stored in the j-th column of the array AB
 *          as follows:
 *          if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-ka)<=i<=j;
 *          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+ka).
 *
 *          On exit, the contents of AB are destroyed.
 *
 *  LDAB    (input) INTEGER
 *          The leading dimension of the array AB.  LDAB >= KA+1.
 *
 *  BB      (input/output) DOUBLE PRECISION array, dimension (LDBB, N)
 *          On entry, the upper or lower triangle of the symmetric band
 *          matrix B, stored in the first kb+1 rows of the array.  The
 *          j-th column of B is stored in the j-th column of the array BB
 *          as follows:
 *          if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-kb)<=i<=j;
 *          if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for j<=i<=min(n,j+kb).
 *
 *          On exit, the factor S from the split Cholesky factorization
 *          B = S**T*S, as returned by DPBSTF.
 *
 *  LDBB    (input) INTEGER
 *          The leading dimension of the array BB.  LDBB >= KB+1.
 *
 *  W       (output) DOUBLE PRECISION array, dimension (N)
 *          If INFO = 0, the eigenvalues in ascending order.
 *
 *  Z       (output) DOUBLE PRECISION array, dimension (LDZ, N)
 *          If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of
 *          eigenvectors, with the i-th column of Z holding the
 *          eigenvector associated with W(i). The eigenvectors are
 *          normalized so that Z**T*B*Z = I.
 *          If JOBZ = 'N', then Z is not referenced.
 *
 *  LDZ     (input) INTEGER
 *          The leading dimension of the array Z.  LDZ >= 1, and if
 *          JOBZ = 'V', LDZ >= N.
 *
 *  WORK    (workspace) DOUBLE PRECISION array, dimension (3*N)
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *          > 0:  if INFO = i, and i is:
 *             <= N:  the algorithm failed to converge:
 *                    i off-diagonal elements of an intermediate
 *                    tridiagonal form did not converge to zero;
 *             > N:   if INFO = N + i, for 1 <= i <= N, then DPBSTF
 *                    returned INFO = i: B is not positive definite.
 *                    The factorization of B could not be completed and
 *                    no eigenvalues or eigenvectors were computed.
 *
 *  =====================================================================
 *
 *     .. Local Scalars ..

DSBGV()

DSBGV(String, String, int, int, int, double[][], double[][], double[], double[][], double[], intW)

 public DSBGV()

 public static void DSBGV(String jobz,
                          String uplo,
                          int n,
                          int ka,
                          int kb,
                          double ab[][],
                          double bb[][],
                          double w[],
                          double z[][],
                          double work[],
                          intW info)

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