/home/coin/SVN-release/OS-2.1.1/Couenne/src/convex/operators/conv-exprQuad.cpp

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00001 /* $Id: conv-exprQuad.cpp 217 2009-07-08 17:02:07Z pbelotti $
00002  *
00003  * Name:    conv-exprQuad.cpp
00004  * Authors: Pierre Bonami
00005  *          Stefan Vigerske
00006  *          Pietro Belotti
00007  * Purpose: implementation of convexification methods for exprQuad
00008  *
00009  * (C) Carnegie-Mellon University, 2006-09.
00010  * This file is licensed under the Common Public License (CPL)
00011  */
00012 
00013 #include "OsiRowCut.hpp"
00014 #include "OsiCuts.hpp"
00015 
00016 #include "exprAux.hpp"
00017 #include "exprQuad.hpp"
00018 #include "exprBQuad.hpp"
00019 #include "CouenneCutGenerator.hpp"
00020 
00022 void exprQuad::getBounds (expression *&lb, expression *&ub) {
00023 
00024   lb = new exprLBQuad (this);
00025   ub = new exprUBQuad (this);
00026 
00027   /*printf ("generated quad bounds:\n  ");
00028   lb -> print (); printf (" [%g]\n  ", (*lb) ());
00029   ub -> print (); printf (" [%g]\n",   (*ub) ());*/
00030 }
00031 
00032 
00034 void exprQuad::getBounds (CouNumber &lb, CouNumber &ub) {
00035   expression::getBounds (lb, ub);
00036 }
00037 
00038 
00039 
00040 // generate equality between *this and *w
00041 void exprQuad::generateCuts (expression *w, //const OsiSolverInterface &si, 
00042                              OsiCuts &cs, const CouenneCutGenerator *cg,
00043                              t_chg_bounds *chg, 
00044                              int wind, CouNumber lb, CouNumber ub) {
00045 
00046   if ((!(cg -> isFirst ())) &&                    // unless a convexification was never created,
00047       (fabs ((*this) () - (*w) ()) < COUENNE_EPS) // do we really need a convexification cut?
00048       || !alphaConvexify (cg -> Problem ()))  // ... or a new alpha-convexification?
00049     return;
00050 
00051   /*int 
00052     nrc = cs.sizeRowCuts (),
00053     ncc = cs.sizeColCuts ();*/
00054 
00055   // generate linear cuts for convex quadratic [upper|lower]-envelope
00056   // of this expression
00057   quadCuts (w, cs, cg);
00058 
00059   /*if (cs.sizeRowCuts () > nrc) {
00060     printf ("------------------ constraint row cuts\n");
00061     for (int i=nrc; i<cs.sizeRowCuts (); i++) 
00062       cs.rowCutPtr (i) -> print ();
00063   }
00064   if (cs.sizeColCuts () > nrc) {
00065     printf ("================== constraint col cuts\n");
00066     for (int i=ncc; i<cs.sizeColCuts (); i++) 
00067       cs.colCutPtr (i) -> print ();
00068       }*/
00069 }

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