org.netlib.lapack
Class SPTRFS
java.lang.Object
org.netlib.lapack.SPTRFS
public class SPTRFS
- extends java.lang.Object
SPTRFS is a simplified interface to the JLAPACK routine sptrfs.
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
* =======
*
* SPTRFS improves the computed solution to a system of linear
* equations when the coefficient matrix is symmetric positive definite
* and tridiagonal, and provides error bounds and backward error
* estimates for the solution.
*
* Arguments
* =========
*
* 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 matrix B. NRHS >= 0.
*
* D (input) REAL array, dimension (N)
* The n diagonal elements of the tridiagonal matrix A.
*
* E (input) REAL array, dimension (N-1)
* The (n-1) subdiagonal elements of the tridiagonal matrix A.
*
* DF (input) REAL array, dimension (N)
* The n diagonal elements of the diagonal matrix D from the
* factorization computed by SPTTRF.
*
* EF (input) REAL array, dimension (N-1)
* The (n-1) subdiagonal elements of the unit bidiagonal factor
* L from the factorization computed by SPTTRF.
*
* 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 SPTTRS.
* 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 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).
*
* 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 (2*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 ..
|
Method Summary |
static void |
SPTRFS(int n,
int nrhs,
float[] d,
float[] e,
float[] df,
float[] ef,
float[][] b,
float[][] x,
float[] ferr,
float[] berr,
float[] work,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SPTRFS
public SPTRFS()
SPTRFS
public static void SPTRFS(int n,
int nrhs,
float[] d,
float[] e,
float[] df,
float[] ef,
float[][] b,
float[][] x,
float[] ferr,
float[] berr,
float[] work,
intW info)