static BigNumber Logarithm(BigNumber y)
{ // y in ( -0.05-, 0.05+ ), return ln((1+y)/(1-y))
BigNumber v = (new BigNumber("1")), y2 = y * y, t = y2, z = t / (new BigNumber("3"));
for (BigNumber i = new BigNumber("3"); CompareNumber.Compare(z, new BigNumber("0")) != 0;
z = (t *= y2) / (i += new BigNumber("2")))
{
v += z;
}
return v * y * (new BigNumber("2"));
}
static void Main(string[] args)
{
BigNumber num = new BigNumber((double).0000201, NumberType2.irrational);
}
public static BigNumber Log10(BigNumber x)
{
return Log(x) / ln10;
}
public static BigNumber Log(BigNumber x)
{
if (CompareNumber.Compare(x, new BigNumber("0")) == -1 || CompareNumber.Compare(x, new BigNumber("0")) == 0) throw new ArgumentException("Must be positive");
int k = 0, l = 0;
for (; CompareNumber.Compare(x, new BigNumber("1")) == 1; k++) x /= new BigNumber("10");
for (; CompareNumber.Compare(x, new BigNumber("0.1")) == -1; k--) x *= new BigNumber("10"); // ( 0.1, 1 ]
for (; CompareNumber.Compare(x, new BigNumber("0.9047")) == -1; l--) x *= new BigNumber("1.2217"); // [ 0.9047, 1.10527199 )
return k * ln10 + l * lnr + Logarithm((x - new BigNumber("1")) / (x + new BigNumber("1")));
}
public static BigNumber Cos(BigNumber x)
{
int precision = 30;
return TaylorFunction.Cosine(x, precision);
}
public static BigNumber Exp(BigNumber x)
{
int precision = 30;
return TaylorFunction.Exp(x, precision);
}
public static BigNumber Pow(BigNumber Num1,BigNumber Num2,int precision = 30)
{
//Num1为底，Num2为幂次
//precision默认为保留30位小数
if (Num2 > 0)
{
return Num1.Power(Num2, precision);
}
else if (Num2 <0)
{
Num2 = 0 - Num2;
return 1 / Num1.Power(Num2, precision);
}
else
{
return 1;
}
}
public static BigNumber Sqrt(BigNumber Num)
{
if (Num <= 0)
{
return 0;
}
else
{
//return Num.Power(0.5, 30);
return DecimalPowerCalculator.Sqrt(Num, 30);
}
}
public static BigNumber[,] MatPlus(BigNumber[,] mat1, BigNumber[,] mat2)
{//矩阵加法
int len11 = mat1.GetLength(0);
int len12 = mat1.GetLength(1);
int len21 = mat2.GetLength(0);
int len22 = mat2.GetLength(1);
if (len11 == len21 && len12 == len22)
{
BigNumber[,] a = new BigNumber[len11, len12];
for (int i = 0; i < len11; i++)
{
for (int j = 0; j < len22; j++)
a[i, j] = 0;
}
for (int i = 0; i < len11; i++)
{
for (int j = 0; j < len12; j++)
{
a[i, j] = mat1[i, j] + mat2[i, j];
}
}
return a;
}
else
{
return null;
}
}
public static BigNumber Double2Big(Double x_bignumber)
{
string NumberStr = x_bignumber.ToString().Trim();
int E_position = -1;
int IsNegative = 0;
int ScientificNotation = 0;
string ScientificNumber;
BigNumber result = new BigNumber("0");
string Scientificupper;
//0为正，1为负
for (int i = 0; i < NumberStr.Length; i++)
{
if (NumberStr[i] == 'E' || NumberStr[i] == 'e')
{
E_position = i;
}
}
if (E_position != -1)
{
ScientificNotation = NumberStr.Length - E_position - 1 - 1;
ScientificNumber = NumberStr.Substring(E_position + 1 + 1, ScientificNotation);
Scientificupper = NumberStr.Substring(0, E_position - 1);
if (NumberStr[E_position + 1] == '-')
{
IsNegative = 1;
result = new BigNumber("-1") * new BigNumber(Scientificupper) * (new BigNumber("10").Power(new BigNumber(ScientificNumber)));
return result;
}
else
{
result = new BigNumber("1") * new BigNumber(Scientificupper) * (new BigNumber("10").Power(new BigNumber(ScientificNumber)));
return result;
}
}
else
{
result = new BigNumber(NumberStr);
return result;
}
}
public static string round(string number, int digits, int type)
{
//type为0时四舍五入，1为ground，2为ceiling
int NumOriginLen = number.Length;
char[] digit_dot = { '.' };
string[] NumberBroken;
NumberBroken = number.Split(digit_dot);
if (digits < 0)
{
digits = 0;
}
if (NumberBroken[0].Length == NumOriginLen)
{
if (digits <= 0)
{
return number;
}
else
{
return NumberBroken[0] + ".".PadRight(digits + 1, '0');
}
}
else
{
string decimal_part = " ";
BigNumber zero_point_one = new BigNumber("0.1");
BigNumber one = new BigNumber("1");
if (NumberBroken[1].Length > digits)
{
if (type == 1)
{
decimal_part = NumberBroken[1].Substring(0, digits);
}
else if (type == 2)
{
BigNumber carry = new BigNumber(digits.ToString());
carry = zero_point_one.Power(carry, 200);
BigNumber number_changed = new BigNumber(number);
number_changed = number_changed + carry;
if (digits <= 0)
{
return number_changed.ToString().Substring(0, NumberBroken[0].Length);
}
return number_changed.ToString().Substring(0, NumOriginLen - (NumberBroken[1].Length - digits));
}
else
{
if (Convert.ToInt32(NumberBroken[1].Substring(digits, 1)) > 4)
{
BigNumber carry = new BigNumber(digits.ToString());
carry = zero_point_one.Power(carry, 200);
BigNumber number_changed = new BigNumber(number);
number_changed = number_changed + carry;
return number_changed.ToString().Substring(0, NumOriginLen - (NumberBroken[1].Length - digits));
}
else
{
decimal_part = NumberBroken[1].Substring(0, digits);
}
}
}
else
{
decimal_part = NumberBroken[1].PadRight(digits, '0');
}
if (decimal_part == "")
{
return NumberBroken[0];
}
return NumberBroken[0] + '.' + decimal_part;
}
}
