@Test
public void testrmul() {

    Matrix M=Matrix.square(20);
    M.randomize(0);
    M.toLower();
    DataBlock B0=new DataBlock(M.getColumnsCount());
    B0.randomize(1);
    DataBlock B1=B0.deepClone();
    
    LowerTriangularMatrix.rmul(M, B0);
    LowerTriangularMatrix.rmul2(M, B1);
    assertTrue(B0.distance(B1)<1e-9);
}