## Introduction

This code implements the Gaussian elimination algorithm in C#.

## Background

Since I was unable to find this algo in C#, I wrote it on my own.

## Using the code

Simply copy and paste the code to your project. If you prefer double precision, replace all occurances of "`float`

" with "`double`

".

public static class LinearEquationSolver
{
public static bool Solve(float[,] M)
{
int rowCount = M.GetUpperBound(0) + 1;
if (M == null || M.Length != rowCount * (rowCount + 1))
throw new ArgumentException("The algorithm must be provided with a (n x n+1) matrix.");
if (rowCount < 1)
throw new ArgumentException("The matrix must at least have one row.");
for (int col = 0; col + 1 < rowCount; col++) if (M[col, col] == 0)
{
int swapRow = col + 1;
for (;swapRow < rowCount; swapRow++) if (M[swapRow, col] != 0) break;
if (M[swapRow, col] != 0) {
float[] tmp = new float[rowCount + 1];
for (int i = 0; i < rowCount + 1; i++)
{ tmp[i] = M[swapRow, i]; M[swapRow, i] = M[col, i]; M[col, i] = tmp[i]; }
}
else return false; }
for (int sourceRow = 0; sourceRow + 1 < rowCount; sourceRow++)
{
for (int destRow = sourceRow + 1; destRow < rowCount; destRow++)
{
float df = M[sourceRow, sourceRow];
float sf = M[destRow, sourceRow];
for (int i = 0; i < rowCount + 1; i++)
M[destRow, i] = M[destRow, i] * df - M[sourceRow, i] * sf;
}
}
for (int row = rowCount - 1; row >= 0; row--)
{
float f = M[row,row];
if (f == 0) return false;
for (int i = 0; i < rowCount + 1; i++) M[row, i] /= f;
for (int destRow = 0; destRow < row; destRow++)
{ M[destRow, rowCount] -= M[destRow, row] * M[row, rowCount]; M[destRow, row] = 0; }
}
return true;
}
}

## Changes