TESTING/LIN/sqrt14.f(3)    Library Functions Manual    TESTING/LIN/sqrt14.f(3)

NAME
       TESTING/LIN/sqrt14.f

SYNOPSIS
   Functions/Subroutines
       real function sqrt14 (trans, m, n, nrhs, a, lda, x, ldx, work, lwork)
           SQRT14

Function/Subroutine Documentation
   real function sqrt14 (character trans, integer m, integer n, integer nrhs,
       real, dimension( lda, * ) a, integer lda, real, dimension( ldx, * ) x,
       integer ldx, real, dimension( lwork ) work, integer lwork)
       SQRT14

       Purpose:


            SQRT14 checks whether X is in the row space of A or A'.  It does so
            by scaling both X and A such that their norms are in the range
            [sqrt(eps), 1/sqrt(eps)], then computing a QR factorization of [A,X]
            (if TRANS = 'T') or an LQ factorization of [A',X]' (if TRANS = 'N'),
            and returning the norm of the trailing triangle, scaled by
            MAX(M,N,NRHS)*eps.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     = 'N':  No transpose, check for X in the row space of A
                     = 'T':  Transpose, check for X in the row space of A'.

           M

                     M is INTEGER
                     The number of rows of the matrix A.

           N

                     N is INTEGER
                     The number of columns of the matrix A.

           NRHS

                     NRHS is INTEGER
                     The number of right hand sides, i.e., the number of columns
                     of X.

           A

                     A is REAL array, dimension (LDA,N)
                     The M-by-N matrix A.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.

           X

                     X is REAL array, dimension (LDX,NRHS)
                     If TRANS = 'N', the N-by-NRHS matrix X.
                     IF TRANS = 'T', the M-by-NRHS matrix X.

           LDX

                     LDX is INTEGER
                     The leading dimension of the array X.

           WORK

                     WORK is REAL array dimension (LWORK)

           LWORK

                     LWORK is INTEGER
                     length of workspace array required
                     If TRANS = 'N', LWORK >= (M+NRHS)*(N+2);
                     if TRANS = 'T', LWORK >= (N+NRHS)*(M+2).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 114 of file sqrt14.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/sqrt14.f(3)