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java.lang.Object | +----org.netlib.lapack.Dporfs
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 * ======= * * DPORFS improves the computed solution to a system of linear * equations when the coefficient matrix is symmetric positive definite, * 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 triangular factor U or L from the Cholesky factorization * A = U**T*U or A = L*L**T, as computed by DPOTRF. * * LDAF (input) INTEGER * The leading dimension of the array AF. LDAF >= 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/output) DOUBLE PRECISION array, dimension (LDX,NRHS) * On entry, the solution matrix X, as computed by DPOTRS. * 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 ..
Dporfs()
dporfs(String, int, int, double[], int, int, double[], int, int, double[], int, int, double[], int, int, double[], int, double[], int, double[], int, int[], int, intW)
Dporfs
public Dporfs()
dporfs
public static void dporfs(String uplo,
int n,
int nrhs,
double a[],
int _a_offset,
int lda,
double af[],
int _af_offset,
int ldaf,
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)
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