public override int Eval(Stack st)
{
int narg = GetNarg(st);
var dgl = GetAlgebraic(st);
var y = GetVariable(st);
var x = GetVariable(st);
var p = Poly.Coefficient(dgl, y, 1);
var q = Poly.Coefficient(dgl, y, 0);
var pi = LambdaINTEGRATE.Integrate(p, x);
if (pi is Rational && !pi.IsNumber())
{
pi = (new LambdaRAT()).SymEval(pi);
}
Variable vexp = new FunctionVariable("exp", pi, new LambdaEXP());
Algebraic dn = new Polynomial(vexp);
var qi = LambdaINTEGRATE.Integrate(q / dn, x);
if (qi is Rational && !qi.IsNumber())
{
qi = (new LambdaRAT()).SymEval(qi);
}
Algebraic cn = new Polynomial(new SimpleVariable("C"));
var res = (qi + cn) * dn;
res = (new ExpandUser()).SymEval(res);
Debug("User Function expand: " + res);
res = (new TrigExpand()).SymEval(res);
Debug("Trigexpand: " + res);
res = (new NormExp()).SymEval(res);
Debug("Norm: " + res);
if (res is Rational)
{
res = (new LambdaRAT()).SymEval(res);
}
res = (new TrigInverseExpand()).SymEval(res);
Debug("Triginverse: " + res);
res = (new SqrtExpand()).SymEval(res);
st.Push(res);
return(0);
}
internal override Algebraic SymEval(Algebraic f)
{
if (gcd.Equals(Symbol.ZERO))
{
return(f);
}
if (f is Polynomial)
{
Polynomial p = ( Polynomial )f;
if (p.Var is FunctionVariable && (( FunctionVariable )p.Var).Name.Equals("exp") && Poly.Degree((( FunctionVariable )p.Var).Var, vr) == 1)
{
var arg = (( FunctionVariable )p.Var).Var;
var new_coef = new Algebraic[2];
new_coef[1] = gcd.ToComplex();
new_coef[0] = Symbol.ZERO;
Algebraic new_arg = new Polynomial(vr, new_coef);
var subst = FunctionVariable.Create("exp", new_arg);
var exp = Poly.Coefficient(arg, vr, 1) / gcd;
if (!(exp is Symbol) && !(( Symbol )exp).IsInteger())
{
throw new SymbolicException("Not integer exponent in exponential simplification.");
}
subst = subst ^ (( Symbol )exp).ToInt();
subst = subst * FunctionVariable.Create("exp", Poly.Coefficient(arg, vr, 0));
var len = p.Coeffs.Length;
var r = SymEval(p[len - 1]);
for (var n = len - 2; n >= 0; n--)
{
r = r * subst + SymEval(p[n]);
}
return(r);
}
}
return(f.Map(this));
}
public static Symbol exp_gcd(ArrayList v, Variable x)
{
var gcd = Symbol.ZERO;
int k = 0;
foreach (var t in v)
{
var a = ( Algebraic )t;
Algebraic c;
if (Poly.Degree(a, x) == 1 && (c = Poly.Coefficient(a, x, 1)) is Symbol)
{
k++;
gcd = gcd.gcd(( Symbol )c);
}
}
return(k > 0 ? gcd : Symbol.ONE);
}