You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
112 lines
3.5 KiB
112 lines
3.5 KiB
2 years ago
|
*> \brief \b XLAENV
|
||
|
|
*
|
||
|
|
* =========== DOCUMENTATION ===========
|
||
|
|
*
|
||
|
|
* Online html documentation available at
|
||
|
|
* http://www.netlib.org/lapack/explore-html/
|
||
|
|
*
|
||
|
|
* Definition:
|
||
|
|
* ===========
|
||
|
|
*
|
||
|
|
* SUBROUTINE XLAENV( ISPEC, NVALUE )
|
||
|
|
*
|
||
|
|
* .. Scalar Arguments ..
|
||
|
|
* INTEGER ISPEC, NVALUE
|
||
|
|
* ..
|
||
|
|
*
|
||
|
|
*
|
||
|
|
*> \par Purpose:
|
||
|
|
* =============
|
||
|
|
*>
|
||
|
|
*> \verbatim
|
||
|
|
*>
|
||
|
|
*> XLAENV sets certain machine- and problem-dependent quantities
|
||
|
|
*> which will later be retrieved by ILAENV.
|
||
|
|
*> \endverbatim
|
||
|
|
*
|
||
|
|
* Arguments:
|
||
|
|
* ==========
|
||
|
|
*
|
||
|
|
*> \param[in] ISPEC
|
||
|
|
*> \verbatim
|
||
|
|
*> ISPEC is INTEGER
|
||
|
|
*> Specifies the parameter to be set in the COMMON array IPARMS.
|
||
|
|
*> = 1: the optimal blocksize; if this value is 1, an unblocked
|
||
|
|
*> algorithm will give the best performance.
|
||
|
|
*> = 2: the minimum block size for which the block routine
|
||
|
|
*> should be used; if the usable block size is less than
|
||
|
|
*> this value, an unblocked routine should be used.
|
||
|
|
*> = 3: the crossover point (in a block routine, for N less
|
||
|
|
*> than this value, an unblocked routine should be used)
|
||
|
|
*> = 4: the number of shifts, used in the nonsymmetric
|
||
|
|
*> eigenvalue routines
|
||
|
|
*> = 5: the minimum column dimension for blocking to be used;
|
||
|
|
*> rectangular blocks must have dimension at least k by m,
|
||
|
|
*> where k is given by ILAENV(2,...) and m by ILAENV(5,...)
|
||
|
|
*> = 6: the crossover point for the SVD (when reducing an m by n
|
||
|
|
*> matrix to bidiagonal form, if max(m,n)/min(m,n) exceeds
|
||
|
|
*> this value, a QR factorization is used first to reduce
|
||
|
|
*> the matrix to a triangular form)
|
||
|
|
*> = 7: the number of processors
|
||
|
|
*> = 8: another crossover point, for the multishift QR and QZ
|
||
|
|
*> methods for nonsymmetric eigenvalue problems.
|
||
|
|
*> = 9: maximum size of the subproblems at the bottom of the
|
||
|
|
*> computation tree in the divide-and-conquer algorithm
|
||
|
|
*> (used by xGELSD and xGESDD)
|
||
|
|
*> =10: ieee NaN arithmetic can be trusted not to trap
|
||
|
|
*> =11: infinity arithmetic can be trusted not to trap
|
||
|
|
*> 12 <= ISPEC <= 16:
|
||
|
|
*> xHSEQR or one of its subroutines,
|
||
|
|
*> see IPARMQ for detailed explanation
|
||
|
|
*> \endverbatim
|
||
|
|
*>
|
||
|
|
*> \param[in] NVALUE
|
||
|
|
*> \verbatim
|
||
|
|
*> NVALUE is INTEGER
|
||
|
|
*> The value of the parameter specified by ISPEC.
|
||
|
|
*> \endverbatim
|
||
|
|
*
|
||
|
|
* Authors:
|
||
|
|
* ========
|
||
|
|
*
|
||
|
|
*> \author Univ. of Tennessee
|
||
|
|
*> \author Univ. of California Berkeley
|
||
|
|
*> \author Univ. of Colorado Denver
|
||
|
|
*> \author NAG Ltd.
|
||
|
|
*
|
||
|
|
*> \ingroup aux_eig
|
||
|
|
*
|
||
|
|
* =====================================================================
|
||
|
|
SUBROUTINE XLAENV( ISPEC, NVALUE )
|
||
|
|
*
|
||
|
|
* -- LAPACK test routine --
|
||
|
|
* -- LAPACK is a software package provided by Univ. of Tennessee, --
|
||
|
|
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
|
||
|
|
*
|
||
|
|
* .. Scalar Arguments ..
|
||
|
|
INTEGER ISPEC, NVALUE
|
||
|
|
* ..
|
||
|
|
*
|
||
|
|
* =====================================================================
|
||
|
|
*
|
||
|
|
* .. Arrays in Common ..
|
||
|
|
INTEGER IPARMS( 100 )
|
||
|
|
* ..
|
||
|
|
* .. Common blocks ..
|
||
|
|
COMMON / CLAENV / IPARMS
|
||
|
|
* ..
|
||
|
|
* .. Save statement ..
|
||
|
|
SAVE / CLAENV /
|
||
|
|
* ..
|
||
|
|
* .. Executable Statements ..
|
||
|
|
*
|
||
|
|
IF( ISPEC.GE.1 .AND. ISPEC.LE.16 ) THEN
|
||
|
|
IPARMS( ISPEC ) = NVALUE
|
||
|
|
END IF
|
||
|
|
*
|
||
|
|
RETURN
|
||
|
|
*
|
||
|
|
* End of XLAENV
|
||
|
|
*
|
||
|
|
END
|