FunctionsTest.java

package io.vivarium.util;

import org.junit.Test;
import org.junit.experimental.categories.Category;

import com.johnuckele.vtest.Tester;

import io.vivarium.test.FastTest;
import io.vivarium.test.UnitTest;

public class FunctionsTest
{
    @Test
    @Category({ FastTest.class, UnitTest.class })
    public void testLogit()
    {
        Tester.equal("0 = logit(0.5)", Functions.logit(0.5), 0, 0.0001);

        Tester.equal("1 = sigmoid(logit(1))", 1, Functions.sigmoid(Functions.logit(1)), 0.0001);

        Tester.equal("-1 = logit(sigmoid(-1))", -1, Functions.logit(Functions.sigmoid(-1)), 0.0001);

        Tester.equal("4.5951 = logit(0.99)", 4.5951, Functions.logit(0.99), 0.0001);
    }

    @Test
    @Category({ FastTest.class, UnitTest.class })
    public void testSigmoid()
    {
        Tester.equal("sigmoid(-1) = 0.2689", 0.2689, Functions.sigmoid(-1), 0.0001);

        Tester.equal("sigmoid(0) = 0.5", 0.5, Functions.sigmoid(0), 0.0001);

        Tester.equal("sigmoid(0.5) = 0.6224", 0.6224, Functions.sigmoid(0.5), 0.0001);

        Tester.equal("sigmoid(1) = 0.7310", 0.7310, Functions.sigmoid(1), 0.0001);

        Tester.equal("sigmoid(4) = 0.9820", 0.9820, Functions.sigmoid(4), 0.0001);
    }

    @Test
    @Category({ FastTest.class, UnitTest.class })
    public void testLogarithmicAverage()
    {
        double a, b, c;

        a = 1;
        b = 1;
        c = 1;
        Tester.equal("avg(1,1) = 1", Math.log(c), Functions.logarithmicAverage(Math.log(a), Math.log(b)), 0.0001);

        a = 3;
        b = 1;
        c = 2;
        Tester.equal("avg(3,1) = 2", Math.log(c), Functions.logarithmicAverage(Math.log(a), Math.log(b)), 0.0001);

        a = 2;
        b = 1;
        c = 1.5;
        Tester.equal("avg(2,1) = 1.5", Math.log(c), Functions.logarithmicAverage(Math.log(a), Math.log(b)), 0.0001);
    }
}