internal static ComplexNumber FindGoodRoot(ComplexNumber @base, IntegerNumber power)
{
var list = new List <ComplexNumber>();
foreach (var root in GetAllRoots(@base, (long)power.Value).FiniteSet())
{
MathS.Settings.FloatToRationalIterCount.Set(15);
MathS.Settings.PrecisionErrorZeroRange.Set(1e-6m);
var downcasted = Functional.Downcast((root as NumberEntity).Value) as ComplexNumber;
MathS.Settings.PrecisionErrorZeroRange.Unset();
MathS.Settings.FloatToRationalIterCount.Unset();
if (downcasted.IsRational() && Number.IsZero(Number.Pow(downcasted, power) - @base)) // To keep user's desired precision
{
return(downcasted);
}
list.Add(downcasted);
}
foreach (var el in list)
{
if (el.IsReal() && (el as RealNumber) > 0)
{
return(el);
}
}
foreach (var el in list)
{
if (el.IsReal())
{
return(el);
}
}
return(list[0]);
}
/// <summary>
/// If the difference between value & round(value) is zero (see Number.IsZero), we consider value as an integer
/// </summary>
/// <param name="value"></param>
/// <param name="res"></param>
/// <returns></returns>
private static bool TryCastToInt(decimal value, out BigInteger res)
{
var intPart = Math.Round(value);
var rest = value - intPart;
if (Number.IsZero(rest))
{
res = (BigInteger)intPart;
return(true);
}
else
{
return(false);
}
}