/// <summary>
/// Swaps the two given rows
/// </summary>
/// <returns>An EpMatrix with the swap performed</returns>
/// <param name="matrix">Matrix.</param>
/// <param name="rowOne">Zero-based index for the first row.</param>
/// <param name="rowTwo">Zero-based index for the second row.</param>
public static EpMatrix SwapRows (EpMatrix matrix, int rowOne, int rowTwo)
{
// tempstore the two rows, then swap them in TheMatrix
int[] firstRow = new int[matrix.GetNumOfColumns()-1];
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
firstRow [i] = matrix.GetElement (rowOne, i);
}
// Copy the second row into the first one
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
matrix.SetElement (rowOne, i, matrix.GetElement (rowTwo, i));
}
// And now the temp into the second row
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
matrix.SetElement (rowOne, i, firstRow [i]);
}
return matrix;
}
/// <summary>
/// Adds two rows from the given matrix together. Stores the result in the first row by convention
/// </summary>
/// <returns>An EpMatrix with the rows added</returns>
/// <param name="matrix">Matrix.</param>
/// <param name="rowOne">Zero-based index for the first row. The result goes in here as well.</param>
/// <param name="rowTwo">Zero-based index for the second row.</param>
public static EpMatrix AddRows (EpMatrix matrix, int rowOne, int rowTwo)
{
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
matrix.SetElement (rowOne, i, matrix.GetElement (rowTwo, i) + matrix.GetElement (rowOne, i));
}
return matrix;
}
/// <summary>
/// Performs a linear combination on two rows. Stores the result in the first row by convention.
/// </summary>
/// <returns>EpMatrix with the combination performed on it</returns>
/// <param name="matrix">Matrix.</param>
/// <param name="rowOne">Zero-based index for the first row</param>
/// <param name="factorOne">Factor to multiply the first rwo by</param>
/// <param name="rowTwo">Zero-based index for the second row</param>
/// <param name="factorTwo">Factor to multiply the second row by</param>
public static EpMatrix LinearCombination (EpMatrix matrix, int rowOne, int factorOne, int rowTwo, int factorTwo)
{
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
matrix.SetElement (rowOne, i,
factorOne * matrix.GetElement (rowOne, i) + factorTwo * matrix.GetElement (rowTwo, i));
}
return matrix;
}
/// <summary>
/// Multiplies two rows together.
/// </summary>
/// <returns>An EpMatrix with the operation performed on it.</returns>
/// <param name="matrix">Matrix.</param>
/// <param name="theRow">Zero-based index for the row.</param>
/// <param name="factor">Factor.</param>
public static EpMatrix MultiplyRow (EpMatrix matrix, int theRow, int factor)
{
for (int i = 0; i < matrix.GetNumOfColumns (); i++) {
matrix.SetElement (theRow, i, matrix.GetElement (theRow, i) * factor);
}
return matrix;
}
