public static HighPrecisionPi GetPi(int digits)
{
Precision = digits;
HighPrecisionPi first = 4 * Atan(5);
HighPrecisionPi second = Atan(239);
return(4 * (first - second));
}
public static HighPrecisionPi Atan(int denominator)
{
HighPrecisionPi result = new HighPrecisionPi(1, denominator);
int xSquared = denominator * denominator;
int divisor = 1;
HighPrecisionPi term = result;
while (!term.IsZero)
{
divisor += 2;
term /= xSquared;
result -= term / divisor;
divisor += 2;
term /= xSquared;
result += term / divisor;
}
return(result);
}
