TESTING/LIN/sqrt16.f(3)    Library Functions Manual    TESTING/LIN/sqrt16.f(3)

NAME
       TESTING/LIN/sqrt16.f

SYNOPSIS
   Functions/Subroutines
       subroutine sqrt16 (trans, m, n, nrhs, a, lda, x, ldx, b, ldb, rwork,
           resid)
           SQRT16

Function/Subroutine Documentation
   subroutine sqrt16 (character trans, integer m, integer n, integer nrhs,
       real, dimension( lda, * ) a, integer lda, real, dimension( ldx, * ) x,
       integer ldx, real, dimension( ldb, * ) b, integer ldb, real, dimension(
       * ) rwork, real resid)
       SQRT16

       Purpose:


            SQRT16 computes the residual for a solution of a system of linear
            equations  A*x = b  or  A'*x = b:
               RESID = norm(B - A*X) / ( max(m,n) * norm(A) * norm(X) * EPS ),
            where EPS is the machine epsilon.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     Specifies the form of the system of equations:
                     = 'N':  A *x = b
                     = 'T':  A'*x = b, where A' is the transpose of A
                     = 'C':  A'*x = b, where A' is the transpose of A

           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of columns of B, the matrix of right hand sides.
                     NRHS >= 0.

           A

                     A is REAL array, dimension (LDA,N)
                     The original M x N matrix A.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           X

                     X is REAL array, dimension (LDX,NRHS)
                     The computed solution vectors for the system of linear
                     equations.

           LDX

                     LDX is INTEGER
                     The leading dimension of the array X.  If TRANS = 'N',
                     LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).

           B

                     B is REAL array, dimension (LDB,NRHS)
                     On entry, the right hand side vectors for the system of
                     linear equations.
                     On exit, B is overwritten with the difference B - A*X.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  IF TRANS = 'N',
                     LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).

           RWORK

                     RWORK is REAL array, dimension (M)

           RESID

                     RESID is REAL
                     The maximum over the number of right hand sides of
                     norm(B - A*X) / ( max(m,n) * norm(A) * norm(X) * EPS ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 131 of file sqrt16.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/LIN/sqrt16.f(3)