geirm 01/06/19 04:44:16
Added: rupert/src/java/org/apache/commons/rupert/nathan
MathTool.java
Log:
Initial commit of contribution from Nathan Bubna <[EMAIL PROTECTED]>
Revision Changes Path
1.1
jakarta-commons-sandbox/rupert/src/java/org/apache/commons/rupert/nathan/MathTool.java
Index: MathTool.java
===================================================================
/*
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.commons.rupert.nathan;
import java.lang.Math;
/**
* Tool for performing floating point math in Velocity
*
* All methods are static. Most take Objects as parameters
* because Velocity wouldn't find the methods otherwise.
*
* @author Nathan Bubna
* @version $Id: MathTool.java,v 1.1 2001/06/19 11:44:15 geirm Exp $
*/
public class MathTool
{
/************* basic math methods ***************/
public static double add(Object num1, Object num2)
{
return toDouble(num1) + toDouble(num2);
}
public static double sub(Object num1, Object num2)
{
return toDouble(num1) - toDouble(num2);
}
public static double mul(Object num1, Object num2)
{
return toDouble(num1) * toDouble(num2);
}
public static double div(Object num1, Object num2)
{
double d1 = toDouble(num1);
double d2 = toDouble(num2);
if (d2 == 0)
{
throw new IllegalArgumentException("Divide by zero!? Shame on you!");
}
return d1 / d2;
}
/************ accessors for some java.lang.Math methods *********/
public static double max(Object num1, Object num2)
{
return Math.max(toDouble(num1), toDouble(num2));
}
public static double min(Object num1, Object num2)
{
return Math.min(toDouble(num1), toDouble(num2));
}
public static double abs(Object num)
{
return Math.abs(toDouble(num));
}
/**
* The toDouble method is a bit of hack used because Velocity
* seems to be passing in literal numbers and Strings representing
numbers
* as members of the Object class.
*
* If the Object passed in is not a valid number, a
NumberFormatException will be thrown.
*
* converts an object with a numeric value into a java double
* will return 0.0 if the object does not contain a numeric value.
*/
public static double toDouble(Object num)
{
double value = 0.0;
if (num instanceof Number)
{
if (num != null)
value = ((Number)num).doubleValue();
}
else if (num instanceof String)
{
value = Double.parseDouble((String)num);
}
else
{
String num_string = String.valueOf(num);
value = Double.parseDouble(num_string);
}
return value;
}
/**
* The toInt method is a bit of hack used because Velocity
* seems to be passing in literal numbers and Strings representing
numbers
* as members of the Object class.
*
* If the Object passed in is not a valid number, a
NumberFormatException will be thrown.
*
* converts an object with a numeric value into a java int
* will return 0 if the object does not contain a numeric value.
*/
public static int toInt(Object num)
{
int value = 0;
if (num instanceof Number)
{
if (num != null)
value = ((Number)num).intValue();
}
else if (num instanceof String)
{
value = Integer.parseInt((String)num);
}
else
{
String num_string = String.valueOf(num);
value = Integer.parseInt(num_string);
}
return value;
}
/**
* rounds a double to the specified number of decimal places
*/
public static double roundTo(int decimals, double value)
{
if (decimals == 0)
{
value = (int)(value + .5);
}
else
{
double shift = Math.pow(10, decimals);
value = value * shift;
value = (int)(value + .5);
value = value / shift;
}
return value;
}
public static double roundTo(Object decimals, Object num)
{
return roundTo(toInt(decimals), toDouble(num));
}
private static int percent (double value)
{
value = roundTo (2, value);
value *= 100;
return (int) value;
}
}
