org.lsmp.djep.sjep.MutiablePolynomial Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jep Show documentation

JEP is a Java library for parsing and evaluating mathematical expressions.

The newest version!

/* @author rich
 * Created on 23-Dec-2004
 *
 * See LICENSE.txt for license information.
 */
package org.lsmp.djep.sjep;
import org.nfunk.jep.*;
/**
 * A mutable polynomial representing a + b + c.
 * There are no requirements that this is in a reduced form
 * so some powers can be zero.
 * 
 * @author Rich Morris
 * Created on 23-Dec-2004
 */
public class MutiablePolynomial
{
	PolynomialCreator pc;
	PNodeI terms[];
	/**
	 * Note arrays parsed may be modified.
	 */
	public MutiablePolynomial(PolynomialCreator pc,PNodeI nodes[])
	{
		this.pc = pc;
		terms = nodes;
	}

	public void add(PNodeI term) throws ParseException
	{
		if(term instanceof PConstant)
			for(int i=0;i 0) {
		 		newTerms[pos] = term;
		 		++pos;
		 		done = true;
			}
			newTerms[pos] = terms[i];
			++pos;
		}
		if(!done)
		{
			newTerms[pos] = term;
			++pos;
		}
		terms = newTerms;
	}

	/**
	 * Multiplies this by a polynomial and expands the results.
	 * (1+x)*(1+x) --> 1+2*x+x^2
	 * @param p the polynomial to multiply by
	 * @throws ParseException
	 */
	void expandMul(Polynomial p) throws ParseException
	{
		PNodeI newTerms[][] = new PNodeI[terms.length][p.terms.length];
		for(int i=0;i 1+2*x+x^2
	 * @param node
	 * @throws ParseException
	 */
	void expandMul(PNodeI node) throws ParseException
	{	
		if(node instanceof Polynomial)	{
			expandMul((Polynomial) node);
			return;
		}
		PNodeI newTerms[] = new PNodeI[terms.length];
		for(int i=0;i 1
			else if(terms[i] instanceof PConstant) {}
			else {
				newTerms[pos] = terms[i];
				++pos;
			}
		}
		terms = newTerms;
	}
	
	PNodeI toPNode() throws ParseException
	{
		reduce();
		if(terms.length ==0) return pc.zeroConstant;
		if(terms.length == 1) return terms[0];
		return new Polynomial(pc,terms);
	}
	
	public String toString() {
		StringBuffer sb = new StringBuffer();
		for(int i=0;i0) sb.append('+');
			sb.append(terms[i].toString());
		}
		return sb.toString();
	}
}