tests: test currents

tests/test_solver.py

@@ -55,7 +55,7 @@ def test_example_sns_1d():
     assert_allclose(rF.squeeze(), F, rtol=0, atol=5e-3 * abs(F).max())
 
 
-@pytest.mark.skip  # TODO
+@pytest.mark.slow
 @pytest.mark.skipif(usadel1 is None, reason="usadel1 not installed")
 def test_example_sns_1d_J_usadel1():
     Lx = 10
@@ -66,7 +66,8 @@ def test_example_sns_1d_J_usadel1():
     T = 0.2
     Delta, I0, _, success = sol.self_consistency(T=T, T_c0=0)
 
-    I0 = I0[0, :-1, 0, 0]
+    tau3 = np.diag([1, 1, -1, -1])
+    I0 = (I0[:-1, 0, 0] @ tau3).trace(axis1=-2, axis2=-1)
 
     I0_mean = I0.real.mean()