/// <summary>
/// Multiplies a matrix by itself <c>n</c> times.
/// </summary>
///
public static double[,] Power(this double[,] matrix, int n)
{
if (matrix == null)
{
throw new ArgumentNullException("matrix");
}
if (!matrix.IsSquare())
{
throw new ArgumentException("Matrix must be square", "matrix");
}
if (n == 0)
{
return(Matrix.Identity(matrix.GetLength(0)));
}
// TODO: Reduce the number of memory allocations
// TODO: Use bitwise operations instead of strings
double[,] result = matrix;
string bin = System.Convert.ToString(n, 2);
for (int i = 1; i < bin.Length; i++)
{
result = Matrix.Dot(result, result);
if (bin[i] == '1')
{
result = Matrix.Dot(result, matrix);
}
}
return(result);
}
