def test_view_of_view(matrix_type, subset_func, subset_func2):
    adata = gen_adata((30, 15), X_type=matrix_type)
    adata.raw = adata
    if subset_func is single_subset:
        pytest.xfail("Other subset generating functions have trouble with this")
    var_s1 = subset_func(adata.var_names, min_size=4)
    var_view1 = adata[:, var_s1]
    var_s2 = subset_func2(var_view1.var_names)
    var_view2 = var_view1[:, var_s2]
    assert var_view2._adata_ref is adata
    obs_s1 = subset_func(adata.obs_names, min_size=4)
    obs_view1 = adata[obs_s1, :]
    obs_s2 = subset_func2(obs_view1.obs_names)
    assert adata[obs_s1, :][:, var_s1][obs_s2, :]._adata_ref is adata

    view_of_actual_copy = adata[:, var_s1].copy()[obs_s1, :].copy()[:, var_s2].copy()

    view_of_view_copy = adata[:, var_s1][obs_s1, :][:, var_s2].copy()

    assert_equal(view_of_actual_copy, view_of_view_copy, exact=True)
def setSaSS(self, lenp2, lenp3, lenp1):
        self.lenp2 = lenp2
        self.lenp3 = lenp3
        self.lenp1 = lenp1
        if(self.lenp1 > (self.lenp2 + self.lenp3)):
        #<CAB 夾角為 180 度, 三點共線且 A 介於 BC 之間
            ret = math.pi
        else :
            # <CAB 夾角為 0, 三點共線且 A 不在 BC 之間
            if((self.lenp1 < (self.lenp2 - self.lenp3)) or (self.lenp1 < (self.lenp3 - self.lenp2))):
                ret = 0.0
            else :
            # 透過餘絃定理求出夾角 <CAB 
                ret = math.acos(((self.lenp2 * self.lenp2 + self.lenp3 * self.lenp3) - self.lenp1 * self.lenp1) / (2 * self.lenp2 * self.lenp3))
        return ret