How to simplify fractions in C#?

Question

I'm looking for a library or existing code to simplify fractions.

Does anyone have anything at hand or any links?

P.S. I already understand the process but really don't want to rewrite the wheel

Update

Ok i've checked out the fraction library on the CodeProject BUT the problem I have is a little bit tricker than simplifying a fraction.

I have to reduce a percentage split which could be 20% / 50% / 30% (always equal to 100%)

Answer 1

I think you just need to divide by the GCD of all the numbers.

void Simplify(int[] numbers)
{
    int gcd = GCD(numbers);
    for (int i = 0; i < numbers.Length; i++)
        numbers[i] /= gcd;
}
int GCD(int a, int b)
{
    while (b > 0)
    {
        int rem = a % b;
        a = b;
        b = rem;
    }
    return a;
}
int GCD(int[] args)
{
    // using LINQ:
    return args.Aggregate((gcd, arg) => GCD(gcd, arg));
}

I haven't tried the code, but it seems simple enough to be right (assuming your numbers are all positive integers and you don't pass an empty array).

Answer 2

You can use Microsoft.FSharp.Math.BigRational, which is in the free F# Power Pack library. Although it depends on F# (which is gratis and included in VS2010), it can be used from C#.

BigRational reduced = BigRational.FromInt(4)/BigRational.FromInt(6);
Console.WriteLine(reduced);
    2/3
Console.WriteLine(reduced.Numerator);
    2
Console.WriteLine(reduced.Denominator);
    3

Answer 3

The best example of Fraction (aka Rational) I've seen is in Timothy Budd's "Classic Data Structures in C++". His implementation is very good. It includes a simple implementation of GCD algorithm.

It shouldn't be hard to adapt to C#.

Answer 4

This library looks like it might be what you need:

var f = new Fraction(numerator, denominator);
numerator = f.Numerator;
denominator = f.Denominator;

Although, I haven't tested it, so it looks like you may need to play around with it to get it to work.