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.
128 lines
2.8 KiB
128 lines
2.8 KiB
*> \brief \b SLADIV
|
|
*
|
|
* =========== DOCUMENTATION ===========
|
|
*
|
|
* Online html documentation available at
|
|
* http://www.netlib.org/lapack/explore-html/
|
|
*
|
|
*> \htmlonly
|
|
*> Download SLADIV + dependencies
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/sladiv.f">
|
|
*> [TGZ]</a>
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/sladiv.f">
|
|
*> [ZIP]</a>
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/sladiv.f">
|
|
*> [TXT]</a>
|
|
*> \endhtmlonly
|
|
*
|
|
* Definition:
|
|
* ===========
|
|
*
|
|
* SUBROUTINE SLADIV( A, B, C, D, P, Q )
|
|
*
|
|
* .. Scalar Arguments ..
|
|
* REAL A, B, C, D, P, Q
|
|
* ..
|
|
*
|
|
*
|
|
*> \par Purpose:
|
|
* =============
|
|
*>
|
|
*> \verbatim
|
|
*>
|
|
*> SLADIV performs complex division in real arithmetic
|
|
*>
|
|
*> a + i*b
|
|
*> p + i*q = ---------
|
|
*> c + i*d
|
|
*>
|
|
*> The algorithm is due to Robert L. Smith and can be found
|
|
*> in D. Knuth, The art of Computer Programming, Vol.2, p.195
|
|
*> \endverbatim
|
|
*
|
|
* Arguments:
|
|
* ==========
|
|
*
|
|
*> \param[in] A
|
|
*> \verbatim
|
|
*> A is REAL
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] B
|
|
*> \verbatim
|
|
*> B is REAL
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] C
|
|
*> \verbatim
|
|
*> C is REAL
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] D
|
|
*> \verbatim
|
|
*> D is REAL
|
|
*> The scalars a, b, c, and d in the above expression.
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[out] P
|
|
*> \verbatim
|
|
*> P is REAL
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[out] Q
|
|
*> \verbatim
|
|
*> Q is REAL
|
|
*> The scalars p and q in the above expression.
|
|
*> \endverbatim
|
|
*
|
|
* Authors:
|
|
* ========
|
|
*
|
|
*> \author Univ. of Tennessee
|
|
*> \author Univ. of California Berkeley
|
|
*> \author Univ. of Colorado Denver
|
|
*> \author NAG Ltd.
|
|
*
|
|
*> \date November 2011
|
|
*
|
|
*> \ingroup auxOTHERauxiliary
|
|
*
|
|
* =====================================================================
|
|
SUBROUTINE SLADIV( A, B, C, D, P, Q )
|
|
*
|
|
* -- LAPACK auxiliary 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 ..
|
|
REAL A, B, C, D, P, Q
|
|
* ..
|
|
*
|
|
* =====================================================================
|
|
*
|
|
* .. Local Scalars ..
|
|
REAL E, F
|
|
* ..
|
|
* .. Intrinsic Functions ..
|
|
INTRINSIC ABS
|
|
* ..
|
|
* .. Executable Statements ..
|
|
*
|
|
IF( ABS( D ).LT.ABS( C ) ) THEN
|
|
E = D / C
|
|
F = C + D*E
|
|
P = ( A+B*E ) / F
|
|
Q = ( B-A*E ) / F
|
|
ELSE
|
|
E = C / D
|
|
F = D + C*E
|
|
P = ( B+A*E ) / F
|
|
Q = ( -A+B*E ) / F
|
|
END IF
|
|
*
|
|
RETURN
|
|
*
|
|
* End of SLADIV
|
|
*
|
|
END
|