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/*
* $Id: SolvableResidueRing.java 4407 2013-04-30 10:34:27Z kredel $
*/
package edu.jas.application;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import org.apache.log4j.Logger;
import edu.jas.gb.SolvableGroebnerBaseAbstract;
import edu.jas.gb.SolvableGroebnerBaseSeq;
import edu.jas.poly.GenPolynomial;
import edu.jas.poly.GenSolvablePolynomial;
import edu.jas.poly.GenSolvablePolynomialRing;
import edu.jas.structure.GcdRingElem;
import edu.jas.structure.RingFactory;
/**
* SolvableResidue ring factory based on GenSolvablePolynomial with RingFactory
* interface. Objects of this class are immutable.
* @author Heinz Kredel
*/
public class SolvableResidueRing> implements RingFactory> {
private static final Logger logger = Logger.getLogger(SolvableResidueRing.class);
//private boolean debug = logger.isDebugEnabled();
/**
* Groebner base engine.
*/
protected final SolvableGroebnerBaseAbstract bb;
/**
* Solvable polynomial ideal for the reduction.
*/
public final SolvableIdeal ideal;
/**
* Polynomial ring of the factory. Shortcut to ideal.list.ring.
*/
public final GenSolvablePolynomialRing ring;
/**
* Indicator if this ring is a field.
*/
protected int isField = -1; // initially unknown
/**
* The constructor creates a SolvableResidueRing object from an Ideal.
* @param i polynomial ideal.
*/
public SolvableResidueRing(SolvableIdeal i) {
this(i, false);
}
/**
* The constructor creates a SolvableResidueRing object from an
* SolvableIdeal.
* @param i solvable polynomial ideal.
* @param isMaximal true, if ideal is maxmal.
*/
public SolvableResidueRing(SolvableIdeal i, boolean isMaximal) {
ideal = i.GB(); // cheap if isGB
ring = ideal.getRing();
bb = new SolvableGroebnerBaseSeq();
if (isMaximal) {
isField = 1;
return;
}
if (ideal.isONE()) {
logger.warn("ideal is one, so all residues are 0");
}
//System.out.println("rr ring = " + ring.getClass().getName());
//System.out.println("rr cofac = " + ring.coFac.getClass().getName());
}
/**
* Is this structure finite or infinite.
* @return true if this structure is finite, else false.
* @see edu.jas.structure.ElemFactory#isFinite()
*/
public boolean isFinite() {
return ideal.commonZeroTest() <= 0 && ring.coFac.isFinite();
}
/**
* Copy SolvableResidue element c.
* @param c
* @return a copy of c.
*/
public SolvableResidue copy(SolvableResidue c) {
//System.out.println("rr copy in = " + c.val);
if (c == null) { // where does this happen?
return getZERO(); // or null?
}
SolvableResidue r = new SolvableResidue(this, c.val);
//System.out.println("rr copy out = " + r.val);
//System.out.println("rr copy ideal = " + ideal.list.list);
return r; //new SolvableResidue( c.ring, c.val );
}
/**
* Get the zero element.
* @return 0 as SolvableResidue.
*/
public SolvableResidue getZERO() {
return new SolvableResidue(this, ring.getZERO());
}
/**
* Get the one element.
* @return 1 as SolvableResidue.
*/
public SolvableResidue getONE() {
SolvableResidue one = new SolvableResidue(this, ring.getONE());
if (one.isZERO()) {
logger.warn("ideal is one, so all residues are 0");
}
return one;
}
/**
* Get a list of the generating elements.
* @return list of generators for the algebraic structure.
* @see edu.jas.structure.ElemFactory#generators()
*/
public List> generators() {
List> pgens = ring.generators();
List> gens = new ArrayList>(pgens.size());
for (GenPolynomial p : pgens) {
GenSolvablePolynomial s = (GenSolvablePolynomial) p;
SolvableResidue r = new SolvableResidue(this, s);
if ( r.isZERO() ) {
continue;
}
if ( !r.isONE() && r.val.isConstant() ) {
continue;
}
gens.add(r);
}
return gens;
}
/**
* Query if this ring is commutative.
* @return true if this ring is commutative, else false.
*/
public boolean isCommutative() {
return ring.isCommutative(); // check also vector space structure
}
/**
* Query if this ring is associative.
* @return true if this ring is associative, else false.
*/
public boolean isAssociative() {
return ring.isAssociative(); // sufficient ??
}
/**
* Query if this ring is a field.
* @return false.
*/
public boolean isField() {
if (isField > 0) {
return true;
}
if (isField == 0) {
return false;
}
// ideal is (complete) prime or maximal ?
return false;
}
/**
* Characteristic of this ring.
* @return characteristic of this ring.
*/
public java.math.BigInteger characteristic() {
return ring.characteristic();
}
/**
* Get a SolvableResidue element from a BigInteger value.
* @param a BigInteger.
* @return a SolvableResidue.
*/
public SolvableResidue fromInteger(java.math.BigInteger a) {
return new SolvableResidue(this, ring.fromInteger(a));
}
/**
* Get a SolvableResidue element from a long value.
* @param a long.
* @return a SolvableResidue.
*/
public SolvableResidue fromInteger(long a) {
return new SolvableResidue(this, ring.fromInteger(a));
}
/**
* Get the String representation as RingFactory.
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "SolvableResidueRing[ " + ideal.toString() + " ]";
}
/**
* Get a scripting compatible string representation.
* @return script compatible representation for this ElemFactory.
* @see edu.jas.structure.ElemFactory#toScript()
*/
@Override
public String toScript() {
// Python case
return "SRC(" + ideal.list.toScript() + ")";
//return "SRC(" + ideal.toScript() + "," + ring.toScript() + ")";
}
/**
* Comparison with any other object.
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
@SuppressWarnings("unchecked")
public boolean equals(Object b) {
if (!(b instanceof SolvableResidueRing)) {
return false;
}
SolvableResidueRing a = null;
try {
a = (SolvableResidueRing) b;
} catch (ClassCastException e) {
}
if (a == null) {
return false;
}
if (!ring.equals(a.ring)) {
return false;
}
return ideal.equals(a.ideal);
}
/**
* Hash code for this residue ring.
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
int h;
h = ideal.hashCode();
return h;
}
/**
* SolvableResidue random.
* @param n such that 0 ≤ v ≤ (2n-1).
* @return a random residue element.
*/
public SolvableResidue random(int n) {
GenSolvablePolynomial x = (GenSolvablePolynomial) ring.random(n).monic();
return new SolvableResidue(this, x);
}
/**
* Generate a random residum polynomial.
* @param k bitsize of random coefficients.
* @param l number of terms.
* @param d maximal degree in each variable.
* @param q density of nozero exponents.
* @return a random residue polynomial.
*/
public SolvableResidue random(int k, int l, int d, float q) {
GenSolvablePolynomial x = (GenSolvablePolynomial) ring.random(k, l, d, q).monic();
return new SolvableResidue(this, x);
}
/**
* SolvableResidue random.
* @param n such that 0 ≤ v ≤ (2n-1).
* @param rnd is a source for random bits.
* @return a random residue element.
*/
public SolvableResidue random(int n, Random rnd) {
GenSolvablePolynomial x = (GenSolvablePolynomial) ring.random(n, rnd).monic();
return new SolvableResidue(this, x);
}
/**
* Parse SolvableResidue from String.
* @param s String.
* @return SolvableResidue from s.
*/
public SolvableResidue parse(String s) {
GenSolvablePolynomial x = ring.parse(s);
return new SolvableResidue(this, x);
}
/**
* Parse SolvableResidue from Reader.
* @param r Reader.
* @return next SolvableResidue from r.
*/
public SolvableResidue parse(Reader r) {
GenSolvablePolynomial x = ring.parse(r);
return new SolvableResidue(this, x);
}
}
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