FIX: ensure that simulations can be performed multiple times (#47)

src/meegsim/coupling_graph.py

@@ -102,12 +102,13 @@ def _set_coupling(sources, coupling_graph, times, random_state):
         # Get the corresponding coupling parameters
         coupling_params = coupling_graph.get_edge_data(name1, name2)
 
-        # Extract the coupling method
-        coupling_fn = coupling_params.pop('method')
+        # Extract the coupling method temporarily
+        tmp_coupling_params = coupling_params.copy()
+        coupling_fn = tmp_coupling_params.pop('method')
 
         # Adjust the waveform of s2 to be coupled with s1
         s2.waveform = coupling_fn(s1.waveform, get_sfreq(times), 
-                                  **coupling_params,
+                                  **tmp_coupling_params,
                                   random_state=random_state)
 
     return sources

tests/test_integration.py

@@ -61,5 +61,14 @@ def test_builtin_methods():
     sc = sim.simulate(sfreq, duration, fwd, random_state=seed)
 
     # SourceConfiguration methods
-    sc.to_stc()
-    sc.to_raw(fwd, info)
+    stc = sc.to_stc()
+    raw = sc.to_raw(fwd, info)
+
+    # Check that it is possible to simulate data multiple times
+    sc_new = sim.simulate(sfreq, duration, fwd, random_state=seed)
+    stc_new = sc_new.to_stc()
+    raw_new = sc_new.to_raw(fwd, info)
+
+    # Check that the result is reproducible
+    assert np.allclose(stc.data, stc_new.data)
+    assert np.allclose(raw.get_data(), raw_new.get_data())