'Test percent keywords.'

def test_percent(self):

    norm = simple_norm(DATA2, stretch='linear', percent=99.0)
    assert_allclose(norm(DATA2), DATA2SCL, atol=0, rtol=1e-05)
    norm2 = simple_norm(DATA2, stretch='linear', min_percent=0.5, max_percent=99.5)
    assert_allclose(norm(DATA2), norm2(DATA2), atol=0, rtol=1e-05)
