public double[][] Dmxm(double a[][], double b[][]) {
        double w;
        double c[][] = new double[3][3];

        TRACE("Dmxm");
        /* Multiply into scratch matrix */
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                w = 0.0;
                for (int k = 0; k < 3; k++) {
                    w += a[i][k] * b[k][j];
                }
                c[i][j] = w;
            }
        }
        ENDTRACE("Dmxm");
        return c;

    }