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*> \brief \b DLADIV** =========== DOCUMENTATION ===========** Online html documentation available at * http://www.netlib.org/lapack/explore-html/ **> \htmlonly*> Download DLADIV + dependencies *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dladiv.f"> *> [TGZ]</a> *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dladiv.f"> *> [ZIP]</a> *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dladiv.f"> *> [TXT]</a>*> \endhtmlonly ** Definition:* ===========** SUBROUTINE DLADIV( A, B, C, D, P, Q )* * .. Scalar Arguments ..* DOUBLE PRECISION A, B, C, D, P, Q* ..* **> \par Purpose:* =============*>*> \verbatim*>*> DLADIV 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 DOUBLE PRECISION*> \endverbatim*>*> \param[in] B*> \verbatim*> B is DOUBLE PRECISION*> \endverbatim*>*> \param[in] C*> \verbatim*> C is DOUBLE PRECISION*> \endverbatim*>*> \param[in] D*> \verbatim*> D is DOUBLE PRECISION*> The scalars a, b, c, and d in the above expression.*> \endverbatim*>*> \param[out] P*> \verbatim*> P is DOUBLE PRECISION*> \endverbatim*>*> \param[out] Q*> \verbatim*> Q is DOUBLE PRECISION*> 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 DLADIV( 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 .. DOUBLE PRECISION A, B, C, D, P, Q* ..** =====================================================================** .. Local Scalars .. DOUBLE PRECISION 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 DLADIV* END
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