/*
* Open Source Physics software is free software as described near the bottom of this code file.
*
* For additional information and documentation on Open Source Physics please see:
* <http://www.opensourcephysics.org/>
*/
package org.opensourcephysics.numerics;
/**
* ParsedFunction defines a function of a single varianble using a String.
*
* This function is immutable. That is, once an instance is created with a particular
* function string, the function cannot be changed. Because immutable
* objects cannot change, they are thread safe and can be freely shared in a Java
* program.
*
* @author Wolfgang Christian
*/
public final class ParsedFunction implements Function {
private final String fStr;
private final Function function;
/**
* Constructs a function x with from the given string.
*
* @param fStr the function
* @throws ParserException
*/
public ParsedFunction(String fStr) throws ParserException {
this(fStr, "x"); //$NON-NLS-1$
}
/**
* Constructs a ParsedFunction from the given string and independent variable.
*
* @param _fStr the function
* @param var the independent variable
* @throws ParserException
*/
public ParsedFunction(String _fStr, String var) throws ParserException {
fStr = _fStr;
SuryonoParser parser = null;
parser = new SuryonoParser(fStr, var);
function = parser;
}
/**
* Evaluates the function, f.
*
* @param x the value of the independent variable
*
* @return the value of the function
*/
public double evaluate(double x) {
return function.evaluate(x);
}
/**
* Represents the function as a string.
*
* @return the string
*/
public String toString() {
return "f(x) = "+fStr; //$NON-NLS-1$
}
}
/*
* Open Source Physics software is free software; you can redistribute
* it and/or modify it under the terms of the GNU General Public License (GPL) as
* published by the Free Software Foundation; either version 2 of the License,
* or(at your option) any later version.
* Code that uses any portion of the code in the org.opensourcephysics package
* or any subpackage (subdirectory) of this package must must also be be released
* under the GNU GPL license.
*
* This software 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA
* or view the license online at http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2007 The Open Source Physics project
* http://www.opensourcephysics.org
*/