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JEP is a Java library for parsing and evaluating mathematical expressions.
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/* @author rich
* Created on 23-Dec-2004
*
* See LICENSE.txt for license information.
*/
package org.lsmp.djep.sjep;
import org.nfunk.jep.*;
/**
* A mutable monomial representing a * x^i * y^j * ... * z^k.
* 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 MutiableMonomial
{
PolynomialCreator pc;
PConstant coeff;
int length;
PNodeI terms[];
PNodeI powers[];
/**
* Note arrays parsed may be modified.
*/
public MutiableMonomial(PolynomialCreator pc,PConstant coeff,PNodeI nodes[],PNodeI pows[])
{
this.pc = pc;
this.coeff = coeff;
length = nodes.length;
terms = nodes;
powers = pows;
}
public void mul(PConstant c) throws ParseException
{
coeff = (PConstant) coeff.mul(c);
}
public void div(PConstant c) throws ParseException
{
coeff = (PConstant) coeff.div(c);
}
public void mul(PNodeI term,PNodeI power) throws ParseException
{
for(int i=0;i 0) {
newTerms[pos] = term;
newPowers[pos] = power;
++pos;
done = true;
}
newTerms[pos] = terms[i];
newPowers[pos] = powers[i];
++pos;
}
if(!done)
{
newTerms[pos] = term;
newPowers[pos] = power;
++pos;
}
length = length+1;
terms = newTerms;
powers = newPowers;
}
void power(PConstant c) throws ParseException
{
coeff = (PConstant) coeff.pow(c);
for(int i=0;i 1
else if(terms[i].isOne()) {} // 1^x --> 1
else if(terms[i] instanceof PConstant && powers[i] instanceof PConstant)
{
coeff = (PConstant) coeff.mul(terms[i].pow(powers[i]));
}
else {
newTerms[pos] = terms[i];
newPowers[pos] = powers[i];
++pos;
}
}
length = newLen;
terms = newTerms;
powers = newPowers;
}
PNodeI toPNode() throws ParseException
{
reduce();
if(length ==0) return coeff;
if(coeff.isZero()) return pc.zeroConstant;
return new Monomial(pc,coeff,terms,powers);
}
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append(coeff.toString());
for(int i=0;i