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00011 #include <math.h>
00012
00013 #include "CouenneExprCos.hpp"
00014 #include "CouenneExprSin.hpp"
00015 #include "CouenneExprBCos.hpp"
00016 #include "CouenneExprOpp.hpp"
00017 #include "CouenneExprMul.hpp"
00018 #include "CouenneExprClone.hpp"
00019
00020 using namespace Couenne;
00021
00022 static const CouNumber
00023 pi = M_PI,
00024 pi2 = M_PI * 2.,
00025 pih = M_PI / 2.;
00026
00027
00028
00029 expression *exprCos::differentiate (int index) {
00030
00031 return new exprOpp (new exprMul (new exprSin (new exprClone (argument_)),
00032 argument_ -> differentiate (index)));
00033 }
00034
00035
00036
00037 void exprCos::getBounds (expression *&lb, expression *&ub) {
00038
00039 expression *xl, *xu;
00040 argument_ -> getBounds (xl, xu);
00041
00042 lb = new exprLBCos (xl, xu);
00043 ub = new exprUBCos (new exprClone (xl), new exprClone (xu));
00044 }
00045
00046
00047 void exprCos::getBounds (CouNumber &lb, CouNumber &ub) {
00048
00049 CouNumber l, u;
00050 argument_ -> getBounds (l, u);
00051
00052 if ((u - l >= pi2) ||
00053 (floor (l/pi2 - 0.5) <
00054 floor (u/pi2 - 0.5)))
00055 lb = -1.;
00056 else lb = CoinMin (cos (l), cos (u));
00057
00058 if ((u - l >= pi2) ||
00059 (floor (l/pi2) <
00060 floor (u/pi2)))
00061 ub = 1.;
00062 else ub = CoinMax (cos (l), cos (u));
00063 }
00064
00065
00067 void exprCos::closestFeasible (expression *varind, expression *vardep,
00068 CouNumber& left, CouNumber& right) const
00069 {
00070 CouNumber curr = (*varind)();
00071 int period = (int)(curr/pi2);
00072 CouNumber curr_noperiod = curr - pi2*period;
00073 CouNumber inv = acos((*vardep)());
00074
00075 if (curr_noperiod < inv) {
00076 left = pi2*period - inv;
00077 right = pi2*period + inv;
00078 }
00079 else if (curr_noperiod < pi2-inv) {
00080 left = pi2*period + inv;
00081 right = pi2*(period+1) - inv;
00082 }
00083 else {
00084 left = pi2*(period+1) - inv;
00085 right = pi2*(period+1) + inv;
00086 }
00087 }