public void TestQRDecompose()
{
var m1 = new MatrixD(new double[] { 5, 2, 1, -1, 3, 3, 0, 1, -1 }, 3, 3 );
//var m1 = new MatrixD(new double[] { 16, 2, 1, 4, -1, 12, 3, -2, 1, 1, -24, 1, 2, -1, 2, 20 }, 4, 4);
Console.WriteLine(m1);
var result = m1.QRDecompose();
Console.WriteLine(result.Q);
Console.WriteLine(result.Q * result.Q.Transpose());
Console.WriteLine(result.R);
Console.WriteLine(result.Q * result.R);
}