Merge branch 'develop' into documentation

pyerrors/obs.py

@@ -1564,6 +1564,25 @@ def load_object(path):
         return pickle.load(file)
 
 
+def import_jackknife(jacks, name):
+    """Imports jackknife samples and returns an Obs
+
+    Parameters
+    ----------
+    jacks : numpy.ndarray
+        numpy array containing the mean value as zeroth entry and
+        the N jackknife samples as first to Nth entry.
+    name : str
+        name of the ensemble the samples are defined on.
+    """
+    length = len(jacks) - 1
+    prj = (np.ones((length, length)) - (length - 1) * np.identity(length))
+    samples = jacks[1:] @ prj
+    new_obs = Obs([samples], [name])
+    new_obs._value = jacks[0]
+    return new_obs
+
+
 def merge_obs(list_of_obs):
     """Combine all observables in list_of_obs into one new observable
 

tests/obs_test.py

@@ -534,3 +534,12 @@ def test_jackknife():
     my_new_obs = my_obs + pe.Obs([full_data], ['test2'])
     with pytest.raises(Exception):
         my_new_obs.export_jackknife()
+
+
+def test_import_jackknife():
+    full_data = np.random.normal(1.105, 0.021, 754)
+    my_obs = pe.Obs([full_data], ['test'])
+    my_jacks = my_obs.export_jackknife()
+    reconstructed_obs = pe.import_jackknife(my_jacks, 'test')
+    assert my_obs == reconstructed_obs
+