org.netlib.lapack
Class Ddisna

java.lang.Object
  org.netlib.lapack.Ddisna

public class Ddisna
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
 *  =======
 *
 *  DDISNA computes the reciprocal condition numbers for the eigenvectors
 *  of a real symmetric or complex Hermitian matrix or for the left or
 *  right singular vectors of a general m-by-n matrix. The reciprocal
 *  condition number is the 'gap' between the corresponding eigenvalue or
 *  singular value and the nearest other one.
 *
 *  The bound on the error, measured by angle in radians, in the I-th
 *  computed vector is given by
 *
 *         DLAMCH( 'E' ) * ( ANORM / SEP( I ) )
 *
 *  where ANORM = 2-norm(A) = max( abs( D(j) ) ).  SEP(I) is not allowed

 *  to be smaller than DLAMCH( 'E' )*ANORM in order to limit the size of

 *  the error bound.
 *
 *  DDISNA may also be used to compute error bounds for eigenvectors of
 *  the generalized symmetric definite eigenproblem.
 *
 *  Arguments
 *  =========
 *
 *  JOB     (input) CHARACTER*1
 *          Specifies for which problem the reciprocal condition numbers

 *          should be computed:
 *          = 'E':  the eigenvectors of a symmetric/Hermitian matrix;
 *          = 'L':  the left singular vectors of a general matrix;
 *          = 'R':  the right singular vectors of a general matrix.
 *
 *  M       (input) INTEGER
 *          The number of rows of the matrix. M >= 0.
 *
 *  N       (input) INTEGER
 *          If JOB = 'L' or 'R', the number of columns of the matrix,
 *          in which case N >= 0. Ignored if JOB = 'E'.
 *
 *  D       (input) DOUBLE PRECISION array, dimension (M) if JOB = 'E'
 *                              dimension (min(M,N)) if JOB = 'L' or 'R'

 *          The eigenvalues (if JOB = 'E') or singular values (if JOB =
 *          'L' or 'R') of the matrix, in either increasing or decreasing
 *          order. If singular values, they must be non-negative.
 *
 *  SEP     (output) DOUBLE PRECISION array, dimension (M) if JOB = 'E'
 *                               dimension (min(M,N)) if JOB = 'L' or 'R'
 *          The reciprocal condition numbers of the vectors.
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit.
 *          < 0:  if INFO = -i, the i-th argument had an illegal value.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Ddisna()

Method Summary

static void

ddisna(java.lang.String job, int m, int n, double[] d, int _d_offset, double[] sep, int _sep_offset, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

Ddisna

public Ddisna()

Method Detail

ddisna

public static void ddisna(java.lang.String job,
                          int m,
                          int n,
                          double[] d,
                          int _d_offset,
                          double[] sep,
                          int _sep_offset,
                          intW info)