org.chocosolver.solver.expression.continuous.arithmetic.BiCArExpression Maven / Gradle / Ivy
/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2019, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver.expression.continuous.arithmetic;
import org.chocosolver.solver.Model;
import org.chocosolver.solver.variables.RealVar;
import org.chocosolver.util.tools.VariableUtils;
/**
* Binary continuous arithmetic expression
*
* Project: choco-solver.
*
* @author Charles Prud'homme
* @since 28/04/2016.
*/
public class BiCArExpression implements CArExpression {
/**
* The model in which the expression is declared
*/
Model model;
/**
* Lazy creation of the underlying variable
*/
RealVar me = null;
/**
* Operator of the arithmetic expression
*/
Operator op;
/**
* The first expression this expression relies on
*/
private CArExpression e1;
/**
* The second expression this expression relies on
*/
private CArExpression e2;
/**
* Builds a binary expression
*
* @param op an operator
* @param e1 an expression
* @param e2 an expression
*/
public BiCArExpression(Operator op, CArExpression e1, CArExpression e2) {
this.op = op;
this.e1 = e1;
this.e2 = e2;
this.model = e1.getModel();
}
@Override
public Model getModel() {
return model;
}
@Override
public RealVar realVar(double p) {
if (me == null) {
RealVar v1 = e1.realVar(p);
RealVar v2 = e2.realVar(p);
double[] bounds;
switch (op) {
case ADD:
bounds = VariableUtils.boundsForAddition(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}={1}+{2}", me, v1, v2).post();
break;
case SUB:
bounds = VariableUtils.boundsForSubstraction(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}={1}-{2}", me, v1, v2).post();
break;
case MUL:
bounds = VariableUtils.boundsForMultiplication(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}={1}*{2}", me, v1, v2).post();
break;
case DIV:
bounds = VariableUtils.boundsForDivision(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}={1}/{2}", me, v1, v2).post();
break;
case POW:
bounds = VariableUtils.boundsForPow(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}={1}^{2}", me, v1, v2).post();
break;
case MIN:
bounds = VariableUtils.boundsForMinimum(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}=min({1},{2})", me, v1, v2).post();
break;
case MAX:
bounds = VariableUtils.boundsForMaximum(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}=max({1},{2})", me, v1, v2).post();
break;
case ATAN2:
bounds = VariableUtils.boundsForAtan2(v1, v2);
me = model.realVar(bounds[0], bounds[1], p);
model.realIbexGenericConstraint("{0}=atan2({1},{2})", me, v1, v2).post();
break;
default:
throw new UnsupportedOperationException("Binary arithmetic expressions does not support " + op.name());
}
}
return me;
}
@Override
public String toString() {
return op.name() + "(" + e1.toString() + "," + e2.toString() + ")";
}
}