public static Pow[] GetNarrowPowers(this Rational r, Rational[] narrows = null)
{
if (narrows == null)
{
narrows = NarrowUtils.GetDefault(r.GetInvolvedPowerCount());
}
int len = r.GetInvolvedPowerCount();
if (len > narrows.Length)
{
return(null);
}
Pow[] res = new Pow[len];
r = r.Clone();
for (int i = len - 1; i >= 0; --i)
{
Pow e = r.GetPrimePower(i);
res[i] = e;
if (e != 0)
{
r /= narrows[i].Power(e);
}
}
return(res);
}
public static string FormatNarrowPowers(this Rational r, Rational[] narrows = null)
{
if (narrows == null)
{
narrows = NarrowUtils.GetDefault(r.GetInvolvedPowerCount());
}
Pow[] pows = GetNarrowPowers(r, narrows);
if (pows == null)
{
return(null); //!!! where invalid narrowPrimes from?
}
return(Powers.ToString(pows, "|}"));
}
public void UpdateNarrows(Rational[] userNarrows = null)
{
_narrows = new Rational[_involvedPrimeCount];
_error = null;
// set default narrows
foreach (Rational item in _items)
{
Rational narrow = NarrowUtils.MakeNarrow(item, _baseItem);
SetNarrow(narrow);
}
// set custom user narrows
if (userNarrows != null)
{
var invalidNarrows = new List <Rational>();
foreach (Rational narrow in userNarrows)
{
if (narrow.IsDefault())
{
continue;
}
if (!IsInRange(narrow))
{
invalidNarrows.Add(narrow);
}
else
{
SetNarrow(narrow);
}
}
if (invalidNarrows.Count > 0)
{
_error = "Narrows out of subgroup: " + String.Join(", ", invalidNarrows);
}
}
// !!! he we should check if resulting narrows can solve each generated rational;
// currently we add all missing narrows (even if it's out of subgroup) instead.
/*
* for (int i = 0; i < _narrows.Length; ++i) {
* if (_narrows[i].IsDefault()) {
* _narrows[i] = NarrowUtils.MakeNarrow(Rational.Prime(i), _baseItem); // default narrow prime
* }
* }
*/
#if DEBUG
Debug.WriteLine("Narrows set: " + Rational.FormatRationals(_narrows));
#endif
}
private bool SetNarrow(Rational n)
{
// make high prime positive
n = NarrowUtils.ValidateNarrow(n);
if (n.IsDefault())
{
return(false);
}
// set narrow to the array - by high prime index
int h = n.GetHighPrimeIndex();
if (0 <= h && h < _narrows.Length)
{
_narrows[h] = n;
return(true);
}
return(false);
}