org.netlib.lapack
Class Dtrrfs

java.lang.Object
  org.netlib.lapack.Dtrrfs

public class Dtrrfs
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
 *  =======
 *
 *  DTRRFS provides error bounds and backward error estimates for the
 *  solution to a system of linear equations with a triangular
 *  coefficient matrix.
 *
 *  The solution matrix X must be computed by DTRTRS or some other
 *  means before entering this routine.  DTRRFS does not do iterative
 *  refinement because doing so cannot improve the backward error.
 *
 *  Arguments
 *  =========
 *
 *  UPLO    (input) CHARACTER*1
 *          = 'U':  A is upper triangular;
 *          = 'L':  A is lower triangular.
 *
 *  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)
 *
 *  DIAG    (input) CHARACTER*1
 *          = 'N':  A is non-unit triangular;
 *          = 'U':  A is unit triangular.
 *
 *  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 triangular matrix A.  If UPLO = 'U', the leading N-by-N
 *          upper triangular part of the array A contains the upper
 *          triangular matrix, and the strictly lower triangular part of

 *          A is not referenced.  If UPLO = 'L', the leading N-by-N lower
 *          triangular part of the array A contains the lower triangular

 *          matrix, and the strictly upper triangular part of A is not
 *          referenced.  If DIAG = 'U', the diagonal elements of A are
 *          also not referenced and are assumed to be 1.
 *
 *  LDA     (input) INTEGER
 *          The leading dimension of the array A.  LDA >= max(1,N).
 *
 *  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) DOUBLE PRECISION array, dimension (LDX,NRHS)
 *          The 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
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dtrrfs()

Method Summary

static void

dtrrfs(java.lang.String uplo, java.lang.String trans, java.lang.String diag, int n, int nrhs, double[] a, int _a_offset, int lda, 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

Dtrrfs

public Dtrrfs()

Method Detail

dtrrfs

public static void dtrrfs(java.lang.String uplo,
                          java.lang.String trans,
                          java.lang.String diag,
                          int n,
                          int nrhs,
                          double[] a,
                          int _a_offset,
                          int lda,
                          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)