internal static bool TryPulling(TrigTable table, ComplexNumber arg, out Entity res)
{
if (arg.IsImaginary())
{
res = null;
return(false);
}
// arg in [0; 2pi]
var dArg = arg.Real.Value;
EDecimal Remainder(EDecimal a, EDecimal divisor)
=> a.RemainderNoRoundAfterDivide(divisor, MathS.Settings.DecimalPrecisionContext);
var twoPi = RealNumber.CtxMultiply(2, MathS.DecimalConst.pi);
dArg = Remainder(
RealNumber.CtxAdd( // (
Remainder(dArg // dArg
, // %
twoPi) // 2pi
, // +
twoPi // 2pi
) // )
, // %
twoPi // 2pi
);
int begin = 0;
int end = table.Count - 1;
while (end - begin > 1)
{
var mid = (end + begin) / 2;
if (EDecimalWrapper.IsGreater(table[mid].arg, dArg))
{
begin = mid;
}
else
{
end = mid;
}
if (end >= table.Count)
{
res = null;
return(false);
}
}
for (var j = begin; j <= end; j++)
{
if (Number.Functional.IsZero(table[j].arg - dArg))
{
res = table[j].res;
return(true);
}
}
res = null;
return(false);
}
/// <summary>
/// Transforms a floating number, but this number should be in [0; 1]
/// </summary>
/// <param name="num"></param>
/// <param name="N"></param>
/// <returns></returns>
internal static string FloatToBaseN(EDecimal num /*should be < 1*/, int N)
{
if (EDecimalWrapper.IsGreater(num, 1) || EDecimalWrapper.IsLess(num, 0))
{
throw new SysException("Error in FloatToBaseN");
}
string res = "";
while (EDecimalWrapper.IsGreater(num, 0))
{
num = RealNumber.CtxMultiply(num, N);
EInteger intPart = num.RoundToIntegerExact(FloorContext).ToEInteger();
res += ALPHABET_TOCHAR[intPart.ToInt32Checked()];
num -= intPart;
}
return(res);
}
private static EDecimal PiOver(int a) => RealNumber.CtxDivide(RealNumber.CtxMultiply(2, MathS.DecimalConst.pi), a);