org.netlib.lapack
Class Dsprfs

java.lang.Object
  extended by org.netlib.lapack.Dsprfs

public class Dsprfs
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 * ======= * * DSPRFS improves the computed solution to a system of linear * equations when the coefficient matrix is symmetric indefinite * and packed, and provides error bounds and backward error estimates * for the solution. * * Arguments * ========= * * UPLO (input) CHARACTER*1 * = 'U': Upper triangle of A is stored; * = 'L': Lower triangle of A is stored. * * 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. * * AP (input) DOUBLE PRECISION array, dimension (N*(N+1)/2) * The upper or lower triangle of the symmetric matrix A, packed * columnwise in a linear array. The j-th column of A is stored * in the array AP as follows: * if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; * if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. * * AFP (input) DOUBLE PRECISION array, dimension (N*(N+1)/2) * The factored form of the matrix A. AFP contains the block * diagonal matrix D and the multipliers used to obtain the * factor U or L from the factorization A = U*D*U**T or * A = L*D*L**T as computed by DSPTRF, stored as a packed * triangular matrix. * * IPIV (input) INTEGER array, dimension (N) * Details of the interchanges and the block structure of D * as determined by DSPTRF. * * 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 DSPTRS. * 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
Dsprfs()
           
 
Method Summary
static void dsprfs(java.lang.String uplo, int n, int nrhs, double[] ap, int _ap_offset, double[] afp, int _afp_offset, 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

Dsprfs

public Dsprfs()
Method Detail

dsprfs

public static void dsprfs(java.lang.String uplo,
                          int n,
                          int nrhs,
                          double[] ap,
                          int _ap_offset,
                          double[] afp,
                          int _afp_offset,
                          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)