public virtual Algebraic ratsubst(Algebraic expr)
{
if (gcd.Equals(Symbol.ZERO))
{
return(expr);
}
if (!expr.Depends(vr))
{
return(expr);
}
if (expr is Rational)
{
return(ratsubst((( Rational )expr).nom) / ratsubst((( Rational )expr).den));
}
if (expr is Polynomial && (( Polynomial )expr).Var is FunctionVariable)
{
var pex = ( Polynomial )expr;
var vex = ( FunctionVariable )pex.Var;
if (vex.Name.Equals("exp") && vex.Var is Polynomial &&
(( Polynomial )vex.Var).Var.Equals(vr) &&
(( Polynomial )vex.Var).Degree() == 1 &&
(( Polynomial )vex.Var)[0].Equals(Symbol.ZERO))
{
int degree = pex.Degree();
var a = new Algebraic[degree + 1];
for (var n = 0; n <= degree; n++)
{
var cf = pex[n];
if (cf.Depends(vr))
{
throw new SymbolicException("Rationalize failed: 2");
}
a[n] = cf;
}
return(new Polynomial(t, a));
}
}
throw new SymbolicException("Could not rationalize " + expr);
}
public SubstExp(Variable vr, Algebraic expr)
{
this.vr = vr;
var list = new ArrayList();
(new GetExpVars2(list)).SymEval(expr);
gcd = Exponential.exp_gcd(list, vr);
if (gcd.Equals(Symbol.ZERO))
{
t = vr;
}
}
