@Override
public IExpr evaluate(final IAST ast) {
Validate.checkRange(ast, 2, 3);
IExpr arg = F.evalExpandAll(ast.get(1));
try {
if (arg.isTimes() || arg.isPower()) {
IExpr[] parts = Apart.getFractionalParts(arg);
if (parts != null) {
if (parts[0].isPlus() && parts[1].isPlus()) {
IAST[] numParts = ((IAST) parts[0]).split(new PolynomialPredicate());
IAST[] denParts = ((IAST) parts[1]).split(new PolynomialPredicate());
IExpr denParts0 = F.eval(denParts[0]);
if (!denParts0.equals(F.C1)) {
IExpr[] result = Cancel.cancelGCD(numParts[0], denParts0);
if (result != null) {
return F.Times(
result[0], numParts[1], F.Power(F.Times(result[1], denParts[1]), F.CN1));
}
}
}
}
}
} catch (JASConversionException jce) {
if (Config.DEBUG) {
jce.printStackTrace();
}
}
return arg;
}
public static boolean polynomialQ(final IExpr polnomialExpr, final IAST variables) {
try {
IExpr expr = F.evalExpandAll(polnomialExpr);
ASTRange r = new ASTRange(variables, 1);
JASConvert<IExpr> jas = new JASConvert<IExpr>(r.toList(), new ExprRingFactory());
return jas.expr2IExprJAS(expr) != null;
} catch (JASConversionException e) {
// exception will be thrown if the expression is not a JAS polynomial
}
return false;
}
@Override
public IExpr evaluate(final IAST lst) {
if (lst.size() >= 3) {
try {
if (lst.get(1).isVector() < 0) {
return null;
}
if (lst.get(2).isVector() < 0) {
return null;
}
if (lst.size() == 3) {
IAST vars = (IAST) lst.get(2);
if (vars.size() <= 1) {
return null;
}
List<ISymbol> varList = new ArrayList<ISymbol>(vars.size() - 1);
String[] pvars = new String[vars.size() - 1];
for (int i = 1; i < vars.size(); i++) {
if (!vars.get(i).isSymbol()) {
return null;
}
varList.add((ISymbol) vars.get(i));
pvars[i - 1] = ((ISymbol) vars.get(i)).toString();
}
GroebnerBasePartial<BigRational> gbp = new GroebnerBasePartial<BigRational>();
IAST polys = (IAST) lst.get(1);
List<GenPolynomial<BigRational>> polyList =
new ArrayList<GenPolynomial<BigRational>>(polys.size() - 1);
JASConvert<BigRational> jas = new JASConvert<BigRational>(varList, BigRational.ZERO);
for (int i = 1; i < polys.size(); i++) {
IExpr expr = F.evalExpandAll(polys.get(i));
GenPolynomial<BigRational> poly = jas.expr2JAS(expr);
polyList.add(poly);
}
OptimizedPolynomialList<BigRational> opl = gbp.partialGB(polyList, pvars);
// System.out.println(opl);
IAST resultList = F.List();
for (GenPolynomial<BigRational> p : opl.list) {
// System.out.println(p);
resultList.add(jas.poly2Expr(p, null));
}
return resultList;
}
} catch (JASConversionException e) {
if (Config.SHOW_STACKTRACE) {
e.printStackTrace();
}
}
}
return null;
}