org.chocosolver.solver.expression.continuous.arithmetic.UnCArExpression Maven / Gradle / Ivy
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/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2023, 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.memory.IStateDouble;
import org.chocosolver.solver.ICause;
import org.chocosolver.solver.Model;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.RealVar;
import org.chocosolver.util.objects.RealInterval;
import org.chocosolver.util.tools.RealUtils;
import java.util.List;
import java.util.TreeSet;
/**
* Unary arithmetic continuous expression
*
* Project: choco-solver.
*
* @author Charles Prud'homme
* @since 28/04/2016.
*/
public class UnCArExpression 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 expression this expression relies on
*/
private final CArExpression e;
IStateDouble l;
IStateDouble u;
/**
* Builds a unary expression
*
* @param op operator
* @param exp an continuous arithmetic expression
*/
public UnCArExpression(Operator op, CArExpression exp) {
this.op = op;
this.e = exp;
this.model = e.getModel();
}
@Override
public Model getModel() {
return model;
}
@Override
public RealVar realVar(double p) {
if (me == null) {
RealVar v = e.realVar(p);
switch (op) {
case NEG:
me = model.realVar(-v.getUB(), -v.getLB(), p);
model.realIbexGenericConstraint("{0}=-{1}", me, v).post();
break;
case ABS:
me = model.realVar(0.0, Math.max(Math.abs(v.getLB()), Math.abs(v.getUB())) , p);
model.realIbexGenericConstraint("{0}=abs({1})", me, v).post();
break;
case EXP:
me = model.realVar(Math.min(Math.exp(v.getLB()), Math.exp(v.getUB())),
Math.max(Math.exp(v.getLB()), Math.exp(v.getUB())), p);
model.realIbexGenericConstraint("{0}=exp({1})", me, v).post();
break;
case LN:
me = model.realVar(Math.min(Math.log(v.getLB()), Math.log(v.getUB())),
Math.max(Math.log(v.getLB()), Math.log(v.getUB())), p);
model.realIbexGenericConstraint("{0}=ln({1})", me, v).post();
break;
case SQR:
RealInterval res2 = RealUtils.iPower(v, 2);
me = model.realVar(res2.getLB(), res2.getUB(), p);
model.realIbexGenericConstraint("{0}={1}^2", me, v).post();
break;
case SQRT:
RealInterval res2_ = RealUtils.iRoot(v, 2);
me = model.realVar(res2_.getLB(), res2_.getUB(), p);
model.realIbexGenericConstraint("{0}=sqrt({1})", me, v).post();
break;
case CUB:
RealInterval res3 = RealUtils.iPower(v, 2);
me = model.realVar(res3.getLB(), res3.getUB(), p);
model.realIbexGenericConstraint("{0}={1}^3", me, v).post();
break;
case CBRT:
RealInterval res3_ = RealUtils.iRoot(v, 3);
me = model.realVar(res3_.getLB(), res3_.getUB(), p);
model.realIbexGenericConstraint("{0}={1}^(1/3)", me, v).post();
break;
case COS:
me = model.realVar(-1.0, 1.0, p);
model.realIbexGenericConstraint("{0}=cos({1})", me, v).post();
break;
case SIN:
me = model.realVar(-1.0, 1.0, p);
model.realIbexGenericConstraint("{0}=sin({1})", me, v).post();
break;
case TAN:
me = model.realVar(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=tan({1})", me, v).post();
break;
case ACOS:
me = model.realVar(0.0, Math.PI, p);
model.realIbexGenericConstraint("{0}=acos({1})", me, v).post();
break;
case ASIN:
me = model.realVar(-Math.PI / 2, Math.PI / 2, p);
model.realIbexGenericConstraint("{0}=asin({1})", me, v).post();
break;
case ATAN:
me = model.realVar(-Math.PI / 2, Math.PI / 2, p);
model.realIbexGenericConstraint("{0}=atan({1})", me, v).post();
break;
case COSH:
me = model.realVar(0.0, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=cosh({1})", me, v).post();
break;
case SINH:
me = model.realVar(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=sinh({1})", me, v).post();
break;
case TANH:
me = model.realVar(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=tanh({1})", me, v).post();
break;
case ACOSH:
me = model.realVar(0.0, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=acosh({1})", me, v).post();
break;
case ASINH:
me = model.realVar(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=asinh({1})", me, v).post();
break;
case ATANH:
me = model.realVar(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, p);
model.realIbexGenericConstraint("{0}=atanh({1})", me, v).post();
break;
default:
throw new UnsupportedOperationException("Unary arithmetic expressions does not support "+op.name());
}
}
return me;
}
@Override
public void tighten() {
RealInterval res;
switch (op) {
case COS:
res = RealUtils.cos(e);
break;
case SIN:
res = RealUtils.sin(e);
break;
case NEG:
res = new RealIntervalConstant(-e.getUB(), -e.getLB());
break;
case SQR:
res = RealUtils.iPower(e, 2);
break;
case SQRT:
res = RealUtils.iRoot(e, 2);
break;
case CUB:
res = RealUtils.iPower(e, 3);
break;
case CBRT:
res = RealUtils.iRoot(e, 3);
break;
case ABS:
double linf = e.getLB();
double lsup = e.getUB();
if(lsup < 0.){
res = new RealIntervalConstant(-lsup, -linf);
}else if (linf < 0.){
res = new RealIntervalConstant(0., Math.max(-linf, lsup));
}else{
res = new RealIntervalConstant(linf, lsup);
}
break;
case EXP:
case LN:
case TAN:
case ACOS:
case ASIN:
case ATAN:
case COSH:
case SINH:
case TANH:
case ACOSH:
case ASINH:
case ATANH:
default:
throw new UnsupportedOperationException("Equation does not support " + op.name()+". Consider using Ibex instead.");
}
l.set(res.getLB());
u.set(res.getUB());
}
@Override
public void project(ICause cause) throws ContradictionException {
RealInterval res;
switch (op) {
case COS:
res = RealUtils.acos_wrt(this, e);
break;
case SIN:
res = RealUtils.asin_wrt(this, e);
break;
case NEG:
res = new RealIntervalConstant(-this.getUB(), -this.getLB());
break;
case SQR:
res = RealUtils.iRoot(this, 2, e);
break;
case SQRT:
res = RealUtils.iPower(this, 2);
break;
case CUB:
res = RealUtils.iRoot(this, 3, e);
break;
case CBRT:
res = RealUtils.iPower(this, 3);
break;
case ABS:
res = new RealIntervalConstant(-this.getUB(), this.getUB());
break;
case EXP:
case LN:
case TAN:
case ACOS:
case ASIN:
case ATAN:
case COSH:
case SINH:
case TANH:
case ACOSH:
case ASINH:
case ATANH:
default:
throw new UnsupportedOperationException("Equation does not support " + op.name()+". Consider using Ibex instead.");
}
e.intersect(res, cause);
}
@Override
public void collectVariables(TreeSet set) {
e.collectVariables(set);
}
@Override
public void subExps(List list) {
e.subExps(list);
list.add(this);
}
@Override
public boolean isolate(RealVar var, List wx, List wox) {
boolean dependsOnX = e.isolate(var, wx, wox);
if (dependsOnX){
wx.add(this);
}
else{
wox.add(this);
}
return dependsOnX;
}
@Override
public void init() {
if(l == null && u == null) {
l = model.getEnvironment().makeFloat(Double.NEGATIVE_INFINITY);
u = model.getEnvironment().makeFloat(Double.POSITIVE_INFINITY);
}
e.init();
}
@Override
public double getLB() {
return l.get();
}
@Override
public double getUB() {
return u.get();
}
@Override
public void intersect(double lb, double ub, ICause cause) throws ContradictionException {
if (lb > getLB()) {
l.set(lb);
}
if (ub < getUB()) {
u.set(ub);
}
if (getLB() > getUB()) {
model.getSolver().throwsException(cause, null, "");
}
}
@Override
public String toString() {
return op.name() + "(" + e.toString() + ")";
}
}