test.uk.co.modularaudio.util.audio.math.FastMathTester.java Source code

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Here is the source code for test.uk.co.modularaudio.util.audio.math.FastMathTester.java

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/**
 *
 * Copyright (C) 2015 - Daniel Hams, Modular Audio Limited
 *                      daniel.hams@gmail.com
 *
 * Mad is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Mad 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Mad.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package test.uk.co.modularaudio.util.audio.math;

import junit.framework.TestCase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import uk.co.modularaudio.util.audio.math.AudioMath;
import uk.co.modularaudio.util.math.FastMath;
import uk.co.modularaudio.util.math.MathFormatter;

public class FastMathTester extends TestCase {
    private static Log log = LogFactory.getLog(FastMathTester.class.getName());

    private final static int NUM_TEST_FLOATS = 8192;
    private final float[] testFloats = new float[NUM_TEST_FLOATS];
    private final float[] outputFloats = new float[NUM_TEST_FLOATS];

    public FastMathTester() {
        for (int i = 0; i < NUM_TEST_FLOATS; ++i) {
            testFloats[i] = (float) Math.random();
        }
    }

    public void testTanhApproximation() {
        final float[] localFloatsToTest = new float[] { 0.0f, 0.1f, 0.2f, 0.3f, 0.4f, 0.5f, 0.6f, 0.7f, 0.8f, 0.9f,
                1.0f, 1.1f, 1.2f, 10.0f, 100.0f, 200.0f, -200.0f, -100.0f, -10.0f, -1.0f, -0.5f, -0.1f, };

        final float[] localOutputFloats = new float[localFloatsToTest.length];

        for (int i = 0; i < localFloatsToTest.length; ++i) {
            final float ftt = localFloatsToTest[i];
            final float jmResult = (float) Math.tanh(ftt);
            localOutputFloats[i] = jmResult;
            final float fmResult = FastMath.fastApproxTanh(ftt);
            localOutputFloats[i] = fmResult;
            final float amResult = AudioMath.tanhNoClip(ftt);
            localOutputFloats[i] = amResult;

            log.debug("Sour(" + MathFormatter.slowFloatPrint(ftt, 12, true) + ")");
            log.debug("Java(" + MathFormatter.slowFloatPrint(jmResult, 12, true) + ")");
            log.debug("Appr(" + MathFormatter.slowFloatPrint(fmResult, 12, true) + ")");
            log.debug("AMAp(" + MathFormatter.slowFloatPrint(amResult, 12, true) + ")");
        }

        for (int i = 0; i < 100; ++i) {
            doOneCycle();
        }
    }

    private void doOneCycle() {

        final long jnb = System.nanoTime();
        for (int i = 0; i < NUM_TEST_FLOATS; ++i) {
            outputFloats[i] = (float) Math.tanh(testFloats[i]);
        }
        final long jna = System.nanoTime();
        final long fb = System.nanoTime();
        for (int i = 0; i < NUM_TEST_FLOATS; ++i) {
            outputFloats[i] = FastMath.fastApproxTanh(testFloats[i]);
        }
        final long fa = System.nanoTime();
        final long amb = System.nanoTime();
        for (int i = 0; i < NUM_TEST_FLOATS; ++i) {
            outputFloats[i] = AudioMath.tanhNoClip(testFloats[i]);
        }
        final long ama = System.nanoTime();
        final long javaTime = jna - jnb;
        final long fastTime = fa - fb;
        final long amTime = ama - amb;
        log.debug("Java nanos " + javaTime + " fast nanos " + fastTime + " audio math tan nanos " + amTime);
    }

}