refactor: unnecessary keywords for call to numdifftools removed, test

against numerical differentiation made stricter.

pyerrors/obs.py

@@ -1123,14 +1123,7 @@ def derived_observable(func, data, array_mode=False, **kwargs):
             raise Exception('Multi mode currently not supported for numerical derivative')
         options = {
             'base_step': 0.1,
-            'step_ratio': 2.5,
-            'num_steps': None,
-            'step_nom': None,
-            'offset': None,
-            'num_extrap': None,
-            'use_exact_steps': None,
-            'check_num_steps': None,
-            'scale': None}
+            'step_ratio': 2.5}
         for key in options.keys():
             kwarg = kwargs.get(key)
             if kwarg is not None:

tests/obs_test.py

@@ -304,7 +304,7 @@ def test_derived_observables():
     d_Obs_fd = pe.derived_observable(lambda x, **kwargs: x[0] * x[1] * np.sin(x[0] * x[1]), [test_obs, test_obs], num_grad=True)
     d_Obs_fd.gamma_method()
 
-    assert d_Obs_ad.value == d_Obs_fd.value
+    assert d_Obs_ad == d_Obs_fd
     assert np.abs(4.0 * np.sin(4.0) - d_Obs_ad.value) < 1000 * np.finfo(np.float64).eps * np.abs(d_Obs_ad.value)
     assert np.abs(d_Obs_ad.dvalue-d_Obs_fd.dvalue) < 1000 * np.finfo(np.float64).eps * d_Obs_ad.dvalue