void ToEchelonForm()
{
int rowCount = _a.RowCount;
int colCount = _a.ColCount;
var matrix = new IndexMatrix(_a);
for (int i = 0, j = 0; i < rowCount && j < colCount; i++, j++)
{
int currentRow = i;
if (!FindPivotIndex(matrix, ref i, ref j))
{
break;
}
if (i > currentRow)
{
matrix.SwapRows(i, currentRow);
i = currentRow;
}
double pivotCoeff = matrix[i, j];
for (int ii = i + 1; ii < rowCount; ii++)
{
double coeff = matrix[ii, j];
if (coeff == 0.0)
{
continue;
}
double multiple = coeff / pivotCoeff;
matrix.AddRowMultiple(ii, -multiple, i);
matrix[ii, j] = 0.0;
}
}
foreach (var c in matrix.CoefficientIterator())
{
_a[c] = c.Value;
}
}
static void Main()
{
Console.WriteLine("Enter number of rows");
int rows = int.Parse(Console.ReadLine());
Console.WriteLine("Enter number of columns");
int columns = int.Parse(Console.ReadLine());
IndexMatrix<int> matrix = new IndexMatrix<int>(rows, columns);
Console.WriteLine("Enter elements");
for (int row = 0; row < rows; row++)
{
for (int column = 0; column < columns; column++)
{
matrix[row, column] = int.Parse(Console.ReadLine());
}
}
Console.WriteLine("Enter row");
int elementRow = int.Parse(Console.ReadLine());
Console.WriteLine("Enter column");
int elementColumn = int.Parse(Console.ReadLine());
Console.WriteLine("Element on position [{0}, {1}] has value {2}",
elementRow, elementColumn, matrix[elementRow, elementColumn]);
}
