Application: gvSIG desktop

package com.iver.utiles;

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program 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 2

 * 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/**

 * Tests for the MathExtension class

 * 

 * @author Pablo Piqueras Bartolom? (p_queras@hotmail.com)

 */

public class TestMathExtension {

	/**

	 * Test method for the TestMathExtension class

	 * 

	 * @param args

	 */

	public static void main(String[] args)

	{

		// Test 1

		System.out.println("Test 1 -> log2(1)");

		showResultState(0, MathExtension.log2(1), 1);

		// Test 2

		System.out.println("Test 2 -> log2(16)");

		showResultState(4, MathExtension.log2(16), 2);

		// Test 3

		System.out.println("Test 3 -> log2Integer(15)");

		showResultState(3, MathExtension.log2Integer(15), 3);

		// Test 4

		System.out.println("Test 4 -> log2Integer(64)");

		showResultState(6, MathExtension.log2Integer(64), 4);

		// Test 5

		System.out.println("Test 5 -> exp2Integer(10)");

		showResultState(1024, MathExtension.exp2Integer(10), 5);

		// Test 6

		System.out.println("Test 6 -> exp2(0)");

		showResultState(1, MathExtension.exp2(0), 6);

		// Test 7

		System.out.println("Test 7 -> exp2Integer(3.5)");

		showResultState(11, MathExtension.exp2Integer(3.5), 7);

		// Test 8

		System.out.println("Test 8 -> logX(e2, e6)");

		showResultState(3, MathExtension.logX(Math.pow(Math.E, 2), Math.pow(Math.E, 6)), 8);

		// Test 9

		System.out.println("Test 9 -> logXInteger(5, 137.43)");

		showResultState(3, MathExtension.logXInteger(5, 137.43), 9);

		// Test 10

		System.out.println("Test 10 -> expXInteger(3.4, 2.1)");

		showResultState(13, MathExtension.expXInteger(3.4, 2.1), 10);

		// There might be more tests

	}

	/**

	 * Indicates if the result of the current test has been successfull or not

	 * 

	 * @param correct The correct result

	 * @param result The result of the operation

	 * @param testNumber The numer of the current test

	 */

	private static void showResultState(double correct, double result, int testNumber) {

		if (correct == result)

			System.out.println("Test " + testNumber + " OK    (Result: " + result + ")");

		else

			System.out.println("Test " + testNumber + " FAILED    (Result: " + result + ")");

	}

}

package com.iver.utiles;

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program 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 2

 * 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/**

 * Some more mathematical functions that 'java.lang.Math' doesn't have

 * 

 * @author Pablo Piqueras Bartolom? (p_queras@hotmail.com)

 */

public final class MathExtension {

	/**

	 * 2-base logarithm of a

	 * @param a

	 * @return

	 */

	public static double log2(double a) {

		return (Math.log(a) / Math.log(2));

	}

	/**

	 * 2-base logarithm of a, but the result doesn't have decimals (approximated to the integer number most near by below)

	 * @param a

	 * @return

	 */

	public static int log2Integer(double a) {

		return (int) Math.floor(log2(a));

	}

	/**

	 * 2 raised to the power a

	 * @param a

	 * @return

	 */

	public static double exp2(double a) {

		return (Math.exp(a * Math.log(2)));

	}

	/**

	 * 2 raised to the power a, but the result doesn't have decimals (approximated to the integer number most near by below)

	 * @param a

	 * @return

	 */

	public static int exp2Integer(double a) {

		return (int) Math.floor(exp2(a));

	}

	/**

	 * X-base logarithm of a

	 * @param a

	 * @return

	 */

	public static double logX(double x_base, double a) {

		return (Math.log(a) / Math.log(x_base));

	}

	/**

	 * X-base logarithm of a, but the result doesn't have decimals (approximated to the integer number most near by below)

	 * @param a

	 * @return

	 */

	public static int logXInteger(double x_base, double a) {

		return (int) Math.floor(logX(x_base, a));

	}

	/**

	 * X raised to the power a

	 * @param a

	 * @return

	 */

	public static double expX(double x, double a) {

		return (Math.exp(a * Math.log(x)));

	}

	/**

	 * X raised to the power a, but the result doesn't have decimals (approximated to the integer number most near by below)

	 * @param a

	 * @return

	 */

	public static int expXInteger(double x, double a) {

		return (int) Math.floor(expX(x, a));

	}

}