TESTING/LIN/zqrt14.f(3)    Library Functions Manual    TESTING/LIN/zqrt14.f(3)

NAME
       TESTING/LIN/zqrt14.f

SYNOPSIS
   Functions/Subroutines
       double precision function zqrt14 (trans, m, n, nrhs, a, lda, x, ldx,
           work, lwork)
           ZQRT14

Function/Subroutine Documentation
   double precision function zqrt14 (character trans, integer m, integer n,
       integer nrhs, complex*16, dimension( lda, * ) a, integer lda,
       complex*16, dimension( ldx, * ) x, integer ldx, complex*16, dimension(
       lwork ) work, integer lwork)
       ZQRT14

       Purpose:


           !>
           !> ZQRT14 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 = 'C') 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
           !>          = 'C':  Conjugate transpose, check for X in 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 COMPLEX*16 array, dimension (LDA,N)
           !>          The M-by-N matrix A.
           !>

           LDA

           !>          LDA is INTEGER
           !>          The leading dimension of the array A.
           !>

           X

           !>          X is COMPLEX*16 array, dimension (LDX,NRHS)
           !>          If TRANS = 'N', the N-by-NRHS matrix X.
           !>          IF TRANS = 'C', the M-by-NRHS matrix X.
           !>

           LDX

           !>          LDX is INTEGER
           !>          The leading dimension of the array X.
           !>

           WORK

           !>          WORK is COMPLEX*16 array dimension (LWORK)
           !>

           LWORK

           !>          LWORK is INTEGER
           !>          length of workspace array required
           !>          If TRANS = 'N', LWORK >= (M+NRHS)*(N+2);
           !>          if TRANS = 'C', 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 zqrt14.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/zqrt14.f(3)