org.netlib.lapack
Class Dptcon

java.lang.Object
  org.netlib.lapack.Dptcon

public class Dptcon
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
 *  =======
 *
 *  DPTCON computes the reciprocal of the condition number (in the
 *  1-norm) of a real symmetric positive definite tridiagonal matrix
 *  using the factorization A = L*D*L**T or A = U**T*D*U computed by
 *  DPTTRF.
 *
 *  Norm(inv(A)) is computed by a direct method, and the reciprocal of
 *  the condition number is computed as
 *               RCOND = 1 / (ANORM * norm(inv(A))).
 *
 *  Arguments
 *  =========
 *
 *  N       (input) INTEGER
 *          The order of the matrix A.  N >= 0.
 *
 *  D       (input) DOUBLE PRECISION array, dimension (N)
 *          The n diagonal elements of the diagonal matrix D from the
 *          factorization of A, as computed by DPTTRF.
 *
 *  E       (input) DOUBLE PRECISION array, dimension (N-1)
 *          The (n-1) off-diagonal elements of the unit bidiagonal factor
 *          U or L from the factorization of A,  as computed by DPTTRF.
 *
 *  ANORM   (input) DOUBLE PRECISION
 *          The 1-norm of the original matrix A.
 *
 *  RCOND   (output) DOUBLE PRECISION
 *          The reciprocal of the condition number of the matrix A,
 *          computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is the
 *          1-norm of inv(A) computed in this routine.
 *
 *  WORK    (workspace) DOUBLE PRECISION array, dimension (N)
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *
 *  Further Details
 *  ===============
 *
 *  The method used is described in Nicholas J. Higham, "Efficient
 *  Algorithms for Computing the Condition Number of a Tridiagonal
 *  Matrix", SIAM J. Sci. Stat. Comput., Vol. 7, No. 1, January 1986.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dptcon()

Method Summary

static void

dptcon(int n, double[] d, int _d_offset, double[] e, int _e_offset, double anorm, doubleW rcond, double[] work, int _work_offset, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

Dptcon

public Dptcon()

Method Detail

dptcon

public static void dptcon(int n,
                          double[] d,
                          int _d_offset,
                          double[] e,
                          int _e_offset,
                          double anorm,
                          doubleW rcond,
                          double[] work,
                          int _work_offset,
                          intW info)