The OpenNET Project / Index page

[ новости /+++ | форум | теги | ]

Интерактивная система просмотра системных руководств (man-ов)

 ТемаНаборКатегория 
 
 [Cписок руководств | Печать]

cptrfs (3)
  • >> cptrfs (3) ( Solaris man: Библиотечные вызовы )
  • 
    NAME
         cptrfs - improve the computed solution to a system of linear
         equations  when the coefficient matrix is Hermitian positive
         definite and tridiagonal,  and  provides  error  bounds  and
         backward error estimates for the solution
    
    SYNOPSIS
         SUBROUTINE CPTRFS( UPLO, N, NRHS, D, E, DF, EF, B,  LDB,  X,
                   LDX, FERR, BERR, WORK, RWORK, INFO )
    
         CHARACTER UPLO
    
         INTEGER INFO, LDB, LDX, N, NRHS
    
         REAL BERR( * ), D( * ), DF( * ), FERR( * ), RWORK( * )
    
         COMPLEX B( LDB, * ), E( * ), EF( * ), WORK( * ), X( LDX, * )
    
    
    
         #include <sunperf.h>
    
         void cptrfs(char uplo, int n, int nrhs,  float  *d,  complex
                   *e,  float *df, complex *ef, complex *cb, int ldb,
                   complex *cx, int ldx, float  *ferr,  float  *berr,
                   int *info) ;
    
    PURPOSE
         CPTRFS improves the computed solution to a system of  linear
         equations  when the coefficient matrix is Hermitian positive
         definite and tridiagonal,  and  provides  error  bounds  and
         backward error estimates for the solution.
    
    
    ARGUMENTS
         UPLO      (input) CHARACTER*1
                   Specifies whether the superdiagonal or the  subdi-
                   agonal  of  the tridiagonal matrix A is stored and
                   the form of the factorization:
                   = 'U':  E is the  superdiagonal  of  A,  and  A  =
                   U**H*D*U;
                   = 'L':  E  is  the  subdiagonal  of  A,  and  A  =
                   L*D*L**H.   (The  two forms are equivalent if A is
                   real.)
    
         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 real diagonal elements  of  the  tridiagonal
                   matrix A.
    
         E         (input) COMPLEX array, dimension (N-1)
                   The (n-1) off-diagonal elements of the tridiagonal
                   matrix A (see UPLO).
    
         DF        (input) REAL array, dimension (N)
                   The n diagonal elements of the diagonal  matrix  D
                   from the factorization computed by CPTTRF.
    
         EF        (input) COMPLEX array, dimension (N-1)
                   The (n-1) off-diagonal elements of the unit  bidi-
                   agonal  factor  U or L from the factorization com-
                   puted by CPTTRF (see UPLO).
    
         B         (input) COMPLEX 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) COMPLEX array, dimension (LDX,NRHS)
                   On entry, the solution matrix X,  as  computed  by
                   CPTTRS.  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) COMPLEX array, dimension (N)
    
         RWORK     (workspace) REAL array, dimension (N)
    
         INFO      (output) INTEGER
                   = 0:  successful exit
                   < 0:  if INFO = -i, the i-th argument had an ille-
                   gal value
    
    
    
    


    Поиск по тексту MAN-ов: 




    Партнёры:
    PostgresPro
    Inferno Solutions
    Hosting by Hoster.ru
    Хостинг:

    Закладки на сайте
    Проследить за страницей
    Created 1996-2024 by Maxim Chirkov
    Добавить, Поддержать, Вебмастеру