org.lightjason.agentspeak.action.builtin.math.linearprogram.CEquationConstraint.java Source code

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/*
 * @cond LICENSE
 * ######################################################################################
 * # LGPL License                                                                       #
 * #                                                                                    #
 * # This file is part of the LightJason AgentSpeak(L++)                                #
 * # Copyright (c) 2015-17, LightJason (info@lightjason.org)                            #
 * # This program is free software: you can redistribute it and/or modify               #
 * # it under the terms of the GNU Lesser General Public License as                     #
 * # published by the Free Software Foundation, either version 3 of the                 #
 * # License, or (at your option) any later version.                                    #
 * #                                                                                    #
 * # This program is distributed in the hope that it will be useful,                    #
 * # but WITHOUT ANY WARRANTY; without even the implied warranty of                     #
 * # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                      #
 * # GNU Lesser General Public License for more details.                                #
 * #                                                                                    #
 * # You should have received a copy of the GNU Lesser General Public License           #
 * # along with this program. If not, see http://www.gnu.org/licenses/                  #
 * ######################################################################################
 * @endcond
 */

package org.lightjason.agentspeak.action.builtin.math.linearprogram;

import com.codepoetics.protonpack.StreamUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.apache.commons.math3.optim.linear.LinearConstraint;
import org.apache.commons.math3.optim.linear.LinearObjectiveFunction;
import org.lightjason.agentspeak.language.CCommon;
import org.lightjason.agentspeak.language.ITerm;
import org.lightjason.agentspeak.language.execution.IContext;
import org.lightjason.agentspeak.language.fuzzy.CFuzzyValue;
import org.lightjason.agentspeak.language.fuzzy.IFuzzyValue;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import java.util.Collection;
import java.util.List;
import java.util.stream.Collectors;

/**
 * add a linear equation constraint to the LP.
 * The arguments of the action contains the left and right side of the equation:
 *
 * + \f$ \left( \sum_{i=1} c_i \cdot x_i \right) + c_{const}    =      \left( \sum_{i=1} r_i \cdot x_i \right) + r_{const} \f$
 * + \f$ \left( \sum_{i=1} c_i \cdot x_i \right) + c_{const}    \geq   \left( \sum_{i=1} r_i \cdot x_i \right) + r_{const} \f$
 * + \f$ \left( \sum_{i=1} c_i \cdot x_i \right) + c_{const}    \leq   \left( \sum_{i=1} r_i \cdot x_i \right) + r_{const} \f$
 *
 * The first arguments is the LP object, the following arguments are the \f$ c_i \f$ values, after that the \f$ c_{const} \f$ value must be added, in the middle
 * of the arguments the relation symbol (\f$ = \f$, \f$ \geq \f$ or \f$ \leq \f$) must be set as string, after that all \f$ r_i \f$
 * elements must be set and the last argument is the \f$ r_{const} \f$, the action fails on wrong input
 *
 * @code math/linearprogram/equationconstraint( LP, [2,7,[7,12,[19]]], "<", [1,2],3,5 ) @endcode
 * @see https://en.wikipedia.org/wiki/Linear_programming
 * @see http://commons.apache.org/proper/commons-math/userguide/optimization.html
 */
public final class CEquationConstraint extends IConstraint {
    /**
     * serial id
     */
    private static final long serialVersionUID = 3123101079239668634L;

    @Nonnegative
    @Override
    public final int minimalArgumentNumber() {
        return 6;
    }

    @Nonnull
    @Override
    public final IFuzzyValue<Boolean> execute(final boolean p_parallel, @Nonnull final IContext p_context,
            @Nonnull final List<ITerm> p_argument, @Nonnull final List<ITerm> p_return) {
        final List<ITerm> l_arguments = CCommon.flatten(p_argument).collect(Collectors.toList());

        // create left-hand-side and right-hand-side with operator lists
        final List<Number> l_lhs = StreamUtils
                .takeWhile(l_arguments.stream().skip(1), i -> !CCommon.rawvalueAssignableTo(i, String.class))
                .map(ITerm::<Number>raw).collect(Collectors.toList());

        final List<ITerm> l_rhs = l_arguments.stream().skip(l_lhs.size() + 1).collect(Collectors.toList());

        // test content
        if ((l_lhs.size() < 2) || (l_rhs.size() < 3) || (!CCommon.rawvalueAssignableTo(l_rhs.get(0), String.class)))
            return CFuzzyValue.from(false);

        // create constraint
        l_arguments.get(0).<Pair<LinearObjectiveFunction, Collection<LinearConstraint>>>raw().getRight()
                .add(new LinearConstraint(

                        // c_i values
                        l_lhs.stream().limit(l_lhs.size() - 1).mapToDouble(Number::doubleValue).toArray(),

                        // c_const value
                        l_lhs.get(l_lhs.size() - 1).doubleValue(),

                        // relation symbol
                        this.getRelation(l_rhs.get(0).<String>raw()),

                        // r_i values
                        l_rhs.stream().limit(l_rhs.size() - 1).skip(1).map(ITerm::<Number>raw)
                                .mapToDouble(Number::doubleValue).toArray(),

                        // r_const value
                        l_rhs.get(l_rhs.size() - 1).<Number>raw().doubleValue()

        ));

        return CFuzzyValue.from(true);
    }

}