myoddweb.bignumber.cpp

Yet another C++ BigNumber implementation with focus on switching between languages.

• PHP BigNumber

The main purpose of this class is to make it easier to write big number functions for scripting languages, (like Javascript or php ).

Usage

In your project

Simply include the files and "src/BigNumber.h" and "src/BigNumber.cpp" in your project.
The other files are just testing and this project.

// in your script
#include "path/to/code/BigNumber.h"

// use it
MyOddWeb::BigNumber lhs = 10;
MyOddWeb::BigNumber rhs = 10;
MyOddWeb::BigNumber sum = lhs.Add( rhs );	// = 20

// good times...

Example

#include "BigNumber.h"

Simple usage:

See the various tests for more sample code.

Big numbers using strings

// using strings
MyOddWeb::BigNumber x("18446744073709551615");
MyOddWeb::BigNumber y("348446744073709551615");
std::string sum = x.Add( y ).ToString();

Integers

// using int
MyOddWeb::BigNumber x(17);
MyOddWeb::BigNumber y(26);
int sum = x.Add( y ).ToInt();

Doubles

// using doubles
MyOddWeb::BigNumber x(17.0);
MyOddWeb::BigNumber y(26.0);
double sum = x.Add( y ).ToDouble();

Convert to another base

// output number to base 2.
MyOddWeb::BigNumber x(5);
std::string base2 = x.ToBase( 2 );	// =101 (base 2)

// fraction/real numbers
// output number to base 8 with decimals.
MyOddWeb::BigNumber x(10.8);
std::string base2 = x.ToBase( 8, 2 );	// =12.63 (base 8)

You can convert from base 2 to base 62

Operations in one line:

Integers

int x = MyOddWeb::BigNumber("17").Add(MyOddWeb::BigNumber("26")).ToInt();

Double

double x = MyOddWeb::BigNumber(1.234).Add(MyOddWeb::BigNumber(2.345)).ToDouble();

Long Double

long double x = MyOddWeb::BigNumber(1.234).Add(MyOddWeb::BigNumber(2.345)).ToLongDouble();

Long Long

long long x = MyOddWeb::BigNumber(1.234).Add( 2222 ).ToLongLong();

Functions

Math functions

• Add( number ) : Add 'number' to 'this' number.
• Sub( number ) : Subtract 'number' from 'this' number.
• Mul( number ) : Multiply 'number' to 'this' number.
• Div( number ) : Divide 'this' by 'number' number.
• Add( number ) : Add 'number' to 'this' number.
• Factorial() : The factorial of this number, (!n)
• Mod( number ) : The mod of 'this' number, (n % m). The remainder of the division.
• Quotient( number ) : : The quotient of dividing 'this' number with this 'number'.
• Pow( number ) : 'this' raised to 'number' (n * n * n * ...).
  • Negative number.
• Exp() : e raised to the power 'this'
• Ln() : logarithm base e of 'this'.
• Log( number ) : logarithm of any base, (number) of 'this'.
• Sin( number ) : The radian sin of 'this' number
• Cos( number ) : The radian cos of 'this' number
• Tan( number ) : The radian tan of 'this' number
• Root( number ) : The nth root of 'this' number.
• Sqrt() : The square root of 'this' number.

Other functions

• IsNeg() : If 'this' number is negative or not.

• IsZero() : If 'this' number is zero or not.

• IsNan() : If 'this' number is Not a number or not, (NAN). This is the result of divide by zero or negative factorials for example.

• IsOdd() : If 'this' number is odd.

• IsEven() : If 'this' number is even.

• Compare( number ) : -ve = smaller / +ve = greater / 0 = same.

  • IsEqual( number ) : If 'this' is equal to 'number'.
  • IsUnequal( number ) : If 'this' is not equal to 'number'.
  • IsGreater( number ) : If 'this' is greater than 'number'.
  • IsLess( number ) : If 'this' is less than 'number'.
  • IsGreaterEqual( number ) : If 'this' is greater or equal to 'number'.
  • IsLessEqual( number ) : If 'this' is less or equal to 'number'.

• IsInteger() : If 'this' number is a whole number positive or negative.

• ToInt() : convert to int.

• ToDouble() : convert to double.

• ToLong() : convert to Long.

• ToLongDouble() : convert to long double.

• ToLongLong() : convert to long long.

• ToString() : Output the number as a string, (if you want to limit the number of decimals use the ToBase( ... ) funtion).

• ToBase( base = 10[, precision=100] ) : convert to string.

  • You can pass a base number to convert to, the default is base 10. The allowed bases are 2-62. The values are 0-9 then A-Z then a-z
  • You can use the precision to limit the number of decimals been returned in the string output.

• Abs() : Get the absolute value of the number

• Trunc( precision ) : Truncate the number, strip the decimals. (+/-n.xyz = n)

• Ceil( precision ) : Round the number up (2.1 = 3 / -2.1 = -2)

• Floor( precision ) : Round the number down (2.1 = 2 / -2.1 = -3)

• Frac() : convert this to a fraction , (-1.2 => -0.2)

• Integer() : convert this to a integer, (1.2 => 1)

• ToDegree( ... ) : convert this from a Radian to a Degree given a certain precision.

• ToRadiant( ... ) : convert this from a Degree to a Radian given a certain precision.

Constants

• e() : Euler's number (to 150 decimals).
• pi(): Pi, (to 150 decimals).

Todo

Functions to do

Math functions

• Sqrt() : The square root of 'this' number.
• Root( number ) : The nth root of 'this' number.
• Factorial() : The factorial of decimal numbers.
• Pow( number ) : Raise 'this' by the 'number' power (n * n * n * ...)
  • Pow( number ) - decimal numbers.
  • Pow( nmuber ) - negative numbs
• Ln( ... ) / Log( ... )
• Gamma()
• Round( precision ) : round a number up/down
• Basic Trigonometric Functions : Sin() / Cos() / Tan()

Other functions

• ToUInt()
• ToShort()
• ToByte()
• ToFloat()
• ToLongLong()
• ToLong
• ToLongDouble
• pi() : constant

Misc

• Mod(2) is often used to check for odd/even, maybe we should short cut those?

• ToDouble( ... ) and ToInt( ... ) do not check if limits are reached.

• Optimise:

  • Multiplication and Divisions, (especially division). Currently they are doing long division and long multiplication. This is not efficient.
  • Factorial, the current implementation does 1 * 2 * 3 * ... and this is slow, (of course). Use the Gamma function.

• Specifically for C++ enable operators

  • operator+
  • operator-
  • operator/
  • operator%
  • operator*

• Do some speed tests / benchmarks / comparison.

• Add version number embeded in the code.

• Create a version.md file