///////////////////////////////////////////////////////////////////////////////
// For information as to what this class does, see the Javadoc, below.       //
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// 2007, 2008, 2009, 2010, 2014, 2015, 2022 by Peter Spirtes, Richard        //
// Scheines, Joseph Ramsey, and Clark Glymour.                               //
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// it under the terms of the GNU General Public License as published by      //
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package edu.cmu.tetrad.test;

import edu.cmu.tetrad.util.MathUtils;
import org.apache.commons.math3.util.FastMath;
import org.junit.Test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;


/**
 * Tests some extra mathematical functions not contained in org.apache.commons.math3.util.FastMath.
 *
 * @author josephramsey
 */
public class TestMathUtils {

    @Test
    public void testLogistic() {
        assertTrue(MathUtils.logistic(0.) == 0.5);
        assertTrue(MathUtils.logistic(-10.) < 1.e-4);
        assertTrue(MathUtils.logistic(+10.) > 1. - 1.e-4);
    }

    @Test
    public void testExpSums() {
        final double d = 100.0;

        assertEquals(7.22E86,
                FastMath.exp(d + d), 1E86);
        assertEquals(7.22E86, FastMath.exp(d) * FastMath.exp(d), 1E86);
    }
}


