Corr array initialization generalized (#203)

* feat: corr array initialization generalized.

* feat: additional checks for three-dimensional arrays added.

* docs: Corr docstring improved.

* docs: typos corrected.

* docs: details about None padding added to Corr docstring.

tests/correlators_test.py

@@ -572,6 +572,27 @@ def test_corr_symmetric():
         assert scorr[0] == corr[0]
 
 
+def test_corr_array_ndim1_init():
+    y = [pe.pseudo_Obs(2 + np.random.normal(0.0, 0.1), .1, 't') for i in np.arange(5)]
+    cc1 = pe.Corr(y)
+    cc2 = pe.Corr(np.array(y))
+    assert np.all([o1 == o2 for o1, o2 in zip(cc1, cc2)])
+
+
+def test_corr_array_ndim3_init():
+    y = np.array([pe.pseudo_Obs(np.random.normal(2.0, 0.1), .1, 't') for i in np.arange(12)]).reshape(3, 2, 2)
+    tt1 = pe.Corr(list(y))
+    tt2 = pe.Corr(y)
+    tt3 = pe.Corr(np.array([pe.Corr(o) for o in y.reshape(3, 4).T]).reshape(2, 2))
+    assert np.all([o1 == o2 for o1, o2 in zip(tt1, tt2)])
+    assert np.all([o1 == o2 for o1, o2 in zip(tt1, tt3)])
+    assert tt1.T == y.shape[0]
+    assert tt1.N == y.shape[1] == y.shape[2]
+
+    with pytest.raises(ValueError):
+        pe.Corr(y.reshape(6, 2, 1))
+
+
 def test_two_matrix_corr_inits():
     T = 4
     rn = lambda : np.random.normal(0.5, 0.1)