matrix = DenseMatrix.OfArray(new double[,]
            {
                        { e, 0, 0, 0 },
                        { 0, e/a, 0, 0 },
                        { 0, 0, -(f + n)/(f - n), -2 * f * n / (f - n) },
                        { 0, 0, -1, 0 }
            });


            matrix = DenseMatrix.OfArray(new double[,]
            {
                        { Math.Cos(Alpha), -Math.Sin(Alpha), 0, 0 },
                        { Math.Sin(Alpha), Math.Cos(Alpha), 0, 0 },
                        { 0, 0, 1, 0 },
                        { 0, 0, 0, 1 }
            });


        readonly Matrix<double> matrix = DenseMatrix.OfArray(new double[,]
        {
                        { 0, 1, 0, -0.5 },
                        { 0, 0, 1, -0.5 },
                        { 1, 0, 0, -3 },
                        { 0, 0, 0, 1 }
        });