@Test
public void testMakeTrendFilter() {

    for (int i = 1; i < 100; ++i) {
        SymmetricFilter filter = TrendCycleFilterFactory.makeTrendFilter(i);
        DataBlock w = new DataBlock(filter.getWeights());
        assertTrue(Math.abs(w.sum() - 1) < 1e-9);
    }
}