com.github.aptd.simulation.elements.common.CMath.java Source code

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Here is the source code for com.github.aptd.simulation.elements.common.CMath.java

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/*
 * @cond LICENSE
 * ######################################################################################
 * # LGPL License                                                                       #
 * #                                                                                    #
 * # This file is part of the Asimov - Agentbased Passenger Train Delay                 #
 * # 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 com.github.aptd.simulation.elements.common;

import cern.colt.matrix.DoubleMatrix1D;
import cern.colt.matrix.DoubleMatrix2D;
import cern.colt.matrix.doublealgo.Formatter;
import cern.colt.matrix.impl.DenseDoubleMatrix1D;
import cern.colt.matrix.impl.DenseDoubleMatrix2D;
import cern.colt.matrix.linalg.Algebra;
import cern.jet.math.Functions;
import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;
import org.apache.commons.math3.random.MersenneTwister;
import org.apache.commons.math3.random.RandomGenerator;
import org.apache.commons.math3.random.SynchronizedRandomGenerator;

import java.util.function.Consumer;
import java.util.stream.Stream;

/**
 * class for global math algorithm
 */
public final class CMath {
    /**
     * reference to global algebra instance
     */
    public static final Algebra ALGEBRA = Algebra.DEFAULT;
    /**
     * synchronized random generator
     */
    public static final RandomGenerator RANDOMGENERATOR = new SynchronizedRandomGenerator(new MersenneTwister());
    /**
     * matrix formatter
     */
    public static final Formatter MATRIXFORMAT = new Formatter();

    static {
        MATRIXFORMAT.setRowSeparator("; ");
        MATRIXFORMAT.setColumnSeparator(",");
        MATRIXFORMAT.setPrintShape(false);
    }

    /**
     * pvate ctor
     */
    private CMath() {
    }

    /**
     * consums a stream of matrix objects
     *
     * @param p_stream stream
     * @param p_consumer consumer function
     * @return stream
     */
    public static Stream<DoubleMatrix1D> matrixconsumer(final Stream<DoubleMatrix1D> p_stream,
            final Consumer<String> p_consumer) {
        return p_stream.peek(i -> p_consumer.accept(MATRIXFORMAT.toString(i) + " "));
    }

    /**
     * creates a rotation matrix
     *
     * @param p_alpha angel in radians
     * @return matrix
     *
     * @see https://en.wikipedia.org/wiki/Rotation_matrix
     */
    public static DoubleMatrix2D rotationmatrix(final double p_alpha) {
        final double l_sin = Math.sin(p_alpha);
        final double l_cos = Math.cos(p_alpha);
        return new DenseDoubleMatrix2D(new double[][] { { l_cos, l_sin }, { -l_sin, l_cos } });
    }

    /**
     * returns the angel
     *
     * @param p_first first vector
     * @param p_second second vector
     * @return pair of angel in radians and boolean for calulation correctness
     */
    public static Pair<Double, Boolean> angle(final DoubleMatrix1D p_first, final DoubleMatrix1D p_second) {
        final double l_first = ALGEBRA.norm2(p_first);
        final double l_second = ALGEBRA.norm2(p_second);

        return (l_first == 0) || (l_second == 0) ? new ImmutablePair<>(0.0, false)
                : new ImmutablePair<>(
                        Math.acos(ALGEBRA.mult(p_first, p_second) / (Math.sqrt(l_first) * Math.sqrt(l_second))),
                        true);
    }

    /**
     * returns the distance between to points
     *
     * @param p_first vector
     * @param p_second vector
     * @return distance
     */
    public static double distance(final DoubleMatrix1D p_first, final DoubleMatrix1D p_second) {
        return ALGEBRA.norm2(new DenseDoubleMatrix1D(p_second.toArray()).assign(p_first, Functions.minus));
    }

}