org.netlib.lapack
Class Dsyrfs
java.lang.Object
org.netlib.lapack.Dsyrfs
public class Dsyrfs
- 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
* =======
*
* DSYRFS improves the computed solution to a system of linear
* equations when the coefficient matrix is symmetric indefinite, 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.
*
* A (input) DOUBLE PRECISION array, dimension (LDA,N)
* The symmetric matrix A. If UPLO = 'U', the leading N-by-N
* upper triangular part of A contains the upper triangular part
* of the matrix A, and the strictly lower triangular part of A
* is not referenced. If UPLO = 'L', the leading N-by-N lower
* triangular part of A contains the lower triangular part of
* the matrix A, and the strictly upper triangular part of A is
* not referenced.
*
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,N).
*
* AF (input) DOUBLE PRECISION array, dimension (LDAF,N)
* The factored form of the matrix A. AF 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 DSYTRF.
*
* LDAF (input) INTEGER
* The leading dimension of the array AF. LDAF >= max(1,N).
*
* IPIV (input) INTEGER array, dimension (N)
* Details of the interchanges and the block structure of D
* as determined by DSYTRF.
*
* 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 DSYTRS.
* 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 ..
Method Summary |
static void |
dsyrfs(java.lang.String uplo,
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 |
Dsyrfs
public Dsyrfs()
dsyrfs
public static void dsyrfs(java.lang.String uplo,
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)