Bugfix: IDAKLU output variables with Experiments (#4753)

* save computed variables in cycle solutions

* Add test for computed variables in cycle solutions

* switch assert_array_almost_equal to assert_allclose
for test_idaklu file

* Trigger RTD build

Author: pipliggins

src/pybamm/solvers/solution.py

@@ -1130,6 +1130,10 @@ def make_cycle_solution(
         sum_sols.all_yps,
         sum_sols.variables_returned,
     )
+
+    if sum_sols.variables_returned:
+        cycle_solution._variables = sum_sols._variables
+
     cycle_solution._all_inputs_casadi = sum_sols.all_inputs_casadi
     cycle_solution._sub_solutions = sum_sols.sub_solutions
 

tests/integration/test_solvers/test_idaklu.py

@@ -133,23 +133,23 @@ def test_interpolation(self):
         t_combined = np.concatenate((sol3.t, t_interp_dense))
         t_combined = np.unique(t_combined)
         t_combined.sort()
-        np.testing.assert_array_almost_equal(sol3.t, t_combined)
+        np.testing.assert_allclose(sol3.t, t_combined)
 
         # 4. sparse t_eval + sparse t_interp
         sol4 = solver.solve(
             model_disc, t_eval_sparse, t_interp=t_interp_sparse, inputs=inputs
         )
-        np.testing.assert_array_almost_equal(sol4.t, np.array([t0, tf]))
+        np.testing.assert_allclose(sol4.t, np.array([t0, tf]))
 
         sols = [sol1, sol2, sol3, sol4]
         for sol in sols:
             # test that y[0] = to true solution
             true_solution = a_value * sol.t
-            np.testing.assert_array_almost_equal(sol.y[0], true_solution)
+            np.testing.assert_allclose(sol.y[0], true_solution)
 
             # test that y[1:3] = to true solution
             true_solution = b_value * sol.t
-            np.testing.assert_array_almost_equal(sol.y[1:3], true_solution)
+            np.testing.assert_allclose(sol.y[1:3], true_solution)
 
     def test_with_experiments(self):
         summary_vars = []
@@ -195,10 +195,16 @@ def test_with_experiments(self):
         np.testing.assert_array_equal(
             sols[0]["Pressure [Pa]"].data, sols[1]["Pressure [Pa]"].data
         )
-        np.testing.assert_array_almost_equal(
+        np.testing.assert_allclose(
             sols[0]["Voltage [V]"].data, sols[1]["Voltage [V]"].data
         )
 
         # check summary variables are the same if output variables are specified
         for var in model.summary_variables:
             assert summary_vars[0][var] == summary_vars[1][var]
+
+        # check variables are accessible for each cycle
+        np.testing.assert_allclose(
+            sols[0].cycles[-1]["Current [A]"].data,
+            sols[1].cycles[-1]["Current [A]"].data,
+        )