org.netlib.lapack
Class SPBRFS

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

public class SPBRFS
extends java.lang.Object

SPBRFS is a simplified interface to the JLAPACK routine spbrfs.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines.  Using this interface also allows you
to omit offset and leading dimension arguments.  However, because
of these conversions, these routines will be slower than the low
level ones.  Following is the description from the original Fortran
source.  Contact seymour@cs.utk.edu with any questions.

* .. * * Purpose * ======= * * SPBRFS improves the computed solution to a system of linear * equations when the coefficient matrix is symmetric positive definite * and banded, 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. * * KD (input) INTEGER * The number of superdiagonals of the matrix A if UPLO = 'U', * or the number of subdiagonals if UPLO = 'L'. KD >= 0. * * NRHS (input) INTEGER * The number of right hand sides, i.e., the number of columns * of the matrices B and X. NRHS >= 0. * * AB (input) REAL array, dimension (LDAB,N) * The upper or lower triangle of the symmetric band matrix A, * stored in the first KD+1 rows of the array. The j-th column * of A is stored in the j-th column of the array AB as follows: * if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; * if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). * * LDAB (input) INTEGER * The leading dimension of the array AB. LDAB >= KD+1. * * AFB (input) REAL array, dimension (LDAFB,N) * The triangular factor U or L from the Cholesky factorization * A = U**T*U or A = L*L**T of the band matrix A as computed by * SPBTRF, in the same storage format as A (see AB). * * LDAFB (input) INTEGER * The leading dimension of the array AFB. LDAFB >= KD+1. * * B (input) REAL 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) REAL array, dimension (LDX,NRHS) * On entry, the solution matrix X, as computed by SPBTRS. * On exit, the improved solution matrix X. * * LDX (input) INTEGER * The leading dimension of the array X. LDX >= max(1,N). * * FERR (output) REAL 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) REAL 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) REAL 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
SPBRFS()
           
 
Method Summary
static void SPBRFS(java.lang.String uplo, int n, int kd, int nrhs, float[][] ab, float[][] afb, float[][] b, float[][] x, float[] ferr, float[] berr, float[] work, int[] iwork, intW info)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SPBRFS

public SPBRFS()
Method Detail

SPBRFS

public static void SPBRFS(java.lang.String uplo,
                          int n,
                          int kd,
                          int nrhs,
                          float[][] ab,
                          float[][] afb,
                          float[][] b,
                          float[][] x,
                          float[] ferr,
                          float[] berr,
                          float[] work,
                          int[] iwork,
                          intW info)