org.netlib.lapack
Class Dgerfs

java.lang.Object
  org.netlib.lapack.Dgerfs

public class Dgerfs
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
 *  =======
 *
 *  DGERFS improves the computed solution to a system of linear
 *  equations and provides error bounds and backward error estimates for

 *  the solution.
 *
 *  Arguments
 *  =========
 *
 *  TRANS   (input) CHARACTER*1
 *          Specifies the form of the system of equations:
 *          = 'N':  A * X = B     (No transpose)
 *          = 'T':  A**T * X = B  (Transpose)
 *          = 'C':  A**H * X = B  (Conjugate transpose = Transpose)
 *
 *  N       (input) INTEGER
 *          The order of the matrix A.  N >= 0.
 *
 *  NRHS    (input) INTEGER
 *          The number of right hand sides, i.e., the number of columns
 *          of the matrices B and X.  NRHS >= 0.
 *
 *  A       (input) DOUBLE PRECISION array, dimension (LDA,N)
 *          The original N-by-N matrix A.
 *
 *  LDA     (input) INTEGER
 *          The leading dimension of the array A.  LDA >= max(1,N).
 *
 *  AF      (input) DOUBLE PRECISION array, dimension (LDAF,N)
 *          The factors L and U from the factorization A = P*L*U
 *          as computed by DGETRF.
 *
 *  LDAF    (input) INTEGER
 *          The leading dimension of the array AF.  LDAF >= max(1,N).
 *
 *  IPIV    (input) INTEGER array, dimension (N)
 *          The pivot indices from DGETRF; for 1<=i<=N, row i of the
 *          matrix was interchanged with row IPIV(i).
 *
 *  B       (input) DOUBLE PRECISION array, dimension (LDB,NRHS)
 *          The right hand side matrix B.
 *
 *  LDB     (input) INTEGER
 *          The leading dimension of the array B.  LDB >= max(1,N).
 *
 *  X       (input/output) DOUBLE PRECISION array, dimension (LDX,NRHS)
 *          On entry, the solution matrix X, as computed by DGETRS.
 *          On exit, the improved solution matrix X.
 *
 *  LDX     (input) INTEGER
 *          The leading dimension of the array X.  LDX >= max(1,N).
 *
 *  FERR    (output) DOUBLE PRECISION array, dimension (NRHS)
 *          The estimated forward error bound for each solution vector
 *          X(j) (the j-th column of the solution matrix X).
 *          If XTRUE is the true solution corresponding to X(j), FERR(j)

 *          is an estimated upper bound for the magnitude of the largest

 *          element in (X(j) - XTRUE) divided by the magnitude of the
 *          largest element in X(j).  The estimate is as reliable as
 *          the estimate for RCOND, and is almost always a slight
 *          overestimate of the true error.
 *
 *  BERR    (output) DOUBLE PRECISION array, dimension (NRHS)
 *          The componentwise relative backward error of each solution
 *          vector X(j) (i.e., the smallest relative change in
 *          any element of A or B that makes X(j) an exact solution).
 *
 *  WORK    (workspace) DOUBLE PRECISION array, dimension (3*N)
 *
 *  IWORK   (workspace) INTEGER array, dimension (N)
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *
 *  Internal Parameters
 *  ===================
 *
 *  ITMAX is the maximum number of steps of iterative refinement.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dgerfs()

Method Summary

static void

dgerfs(java.lang.String trans, int n, int nrhs, double[] a, int _a_offset, int lda, double[] af, int _af_offset, int ldaf, int[] ipiv, int _ipiv_offset, double[] b, int _b_offset, int ldb, double[] x, int _x_offset, int ldx, double[] ferr, int _ferr_offset, double[] berr, int _berr_offset, double[] work, int _work_offset, int[] iwork, int _iwork_offset, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

Dgerfs

public Dgerfs()

Method Detail

dgerfs

public static void dgerfs(java.lang.String trans,
                          int n,
                          int nrhs,
                          double[] a,
                          int _a_offset,
                          int lda,
                          double[] af,
                          int _af_offset,
                          int ldaf,
                          int[] ipiv,
                          int _ipiv_offset,
                          double[] b,
                          int _b_offset,
                          int ldb,
                          double[] x,
                          int _x_offset,
                          int ldx,
                          double[] ferr,
                          int _ferr_offset,
                          double[] berr,
                          int _berr_offset,
                          double[] work,
                          int _work_offset,
                          int[] iwork,
                          int _iwork_offset,
                          intW info)