sgennd.f

Go to the documentation of this file.

*> \brief \b SGENND
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at 
*            http://www.netlib.org/lapack/explore-html/ 
*
*  Definition:
*  ===========
*
*       LOGICAL FUNCTION SGENND (M, N, A, LDA)
* 
*       .. Scalar Arguments ..
*       INTEGER M, N, LDA
*       ..
*       .. Array Arguments ..
*       REAL A( LDA, * )
*       ..
*  
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*>    SGENND tests that its argument has a non-negative diagonal.
*> \endverbatim
*
*  Arguments:
*  ==========
*
*> \param[in] M
*> \verbatim
*>          M is INTEGER
*>          The number of rows in A.
*> \endverbatim
*>
*> \param[in] N
*> \verbatim
*>          N is INTEGER
*>          The number of columns in A.
*> \endverbatim
*>
*> \param[in] A
*> \verbatim
*>          A is REAL array, dimension (LDA, N)
*>          The matrix.
*> \endverbatim
*>
*> \param[in] LDA
*> \verbatim
*>          LDA is INTEGER
*>          Leading dimension of A.
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee 
*> \author Univ. of California Berkeley 
*> \author Univ. of Colorado Denver 
*> \author NAG Ltd. 
*
*> \date November 2011
*
*> \ingroup single_lin
*
*  =====================================================================
      LOGICAL FUNCTION sgennd (M, N, A, LDA)
*
*  -- LAPACK test routine (version 3.4.0) --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     November 2011
*
*     .. Scalar Arguments ..
      INTEGER M, N, LDA
*     ..
*     .. Array Arguments ..
      REAL A( lda, * )
*     ..
*
*  =====================================================================
*
*     .. Parameters ..
      REAL               ZERO
      parameter                ( zero = 0.0e0 )
*     ..
*     .. Local Scalars ..
      INTEGER I, K
*     ..
*     .. Intrinsics ..
      INTRINSIC min
*     ..
*     .. Executable Statements ..
      k = min( m, n )
      DO i = 1, k
         IF( a( i, i ).LT.zero ) THEN
            sgennd = .false.
            RETURN
         END IF
      END DO
      sgennd = .true.
      RETURN
      END