Remove time check from Jax tests to improve stability (#3963)

* Remove time checks in tests

* Old changelog

CHANGELOG.md

@@ -28,6 +28,7 @@
 
 ## Breaking changes
 
+- Removed support for Python 3.8 ([#3961](https://github.com/pybamm-team/PyBaMM/pull/3961))
 - Renamed "ocp_soc_0_dimensional" to "ocp_soc_0" and "ocp_soc_100_dimensional" to "ocp_soc_100" ([#3942](https://github.com/pybamm-team/PyBaMM/pull/3942))
 - The ODES solver was removed due to compatibility issues. Users should use IDAKLU, Casadi, or JAX instead. ([#3932](https://github.com/pybamm-team/PyBaMM/pull/3932))
 - Integrated the `[pandas]` extra into the core PyBaMM package, deprecating the `pybamm[pandas]` optional dependency. Pandas is now a required dependency and will be installed upon installing PyBaMM ([#3892](https://github.com/pybamm-team/PyBaMM/pull/3892))

tests/unit/test_solvers/test_jax_bdf_solver.py

@@ -3,7 +3,6 @@
 from tests import get_mesh_for_testing
 from tests import TestCase
 import sys
-import time
 import numpy as np
 
 if pybamm.have_jax():
@@ -36,19 +35,12 @@ def test_solver_(self):  # Trailing _ manipulates the random seed
         def fun(y, t):
             return rhs(t=t, y=y).reshape(-1)
 
-        t0 = time.perf_counter()
         y = pybamm.jax_bdf_integrate(fun, y0, t_eval, rtol=1e-8, atol=1e-8)
-        t1 = time.perf_counter() - t0
 
         # test accuracy
         np.testing.assert_allclose(y[:, 0], np.exp(0.1 * t_eval), rtol=1e-6, atol=1e-6)
 
-        t0 = time.perf_counter()
         y = pybamm.jax_bdf_integrate(fun, y0, t_eval, rtol=1e-8, atol=1e-8)
-        t2 = time.perf_counter() - t0
-
-        # second run should be much quicker
-        self.assertLess(t2, t1)
 
         # test second run is accurate
         np.testing.assert_allclose(y[:, 0], np.exp(0.1 * t_eval), rtol=1e-6, atol=1e-6)
@@ -66,21 +58,14 @@ def fun(y, t):
         # this as a guess
         y0 = jax.numpy.array([1.0, 1.5])
 
-        t0 = time.perf_counter()
         y = pybamm.jax_bdf_integrate(fun, y0, t_eval, mass=mass, rtol=1e-8, atol=1e-8)
-        t1 = time.perf_counter() - t0
 
         # test accuracy
         soln = np.exp(0.05 * t_eval)
         np.testing.assert_allclose(y[:, 0], soln, rtol=1e-7, atol=1e-7)
         np.testing.assert_allclose(y[:, 1], 2.0 * soln, rtol=1e-7, atol=1e-7)
 
-        t0 = time.perf_counter()
         y = pybamm.jax_bdf_integrate(fun, y0, t_eval, mass=mass, rtol=1e-8, atol=1e-8)
-        t2 = time.perf_counter() - t0
-
-        # second run should be much quicker
-        self.assertLess(t2, t1)
 
         # test second run is accurate
         np.testing.assert_allclose(y[:, 0], np.exp(0.05 * t_eval), rtol=1e-7, atol=1e-7)

tests/unit/test_solvers/test_jax_solver.py

@@ -3,7 +3,6 @@
 from tests import get_mesh_for_testing
 from tests import TestCase
 import sys
-import time
 import numpy as np
 
 if pybamm.have_jax():
@@ -32,9 +31,7 @@ def test_model_solver(self):
             # Solve
             solver = pybamm.JaxSolver(method=method, rtol=1e-8, atol=1e-8)
             t_eval = np.linspace(0, 1, 80)
-            t0 = time.perf_counter()
             solution = solver.solve(model, t_eval)
-            t_first_solve = time.perf_counter() - t0
             np.testing.assert_array_equal(solution.t, t_eval)
             np.testing.assert_allclose(
                 solution.y[0], np.exp(0.1 * solution.t), rtol=1e-6, atol=1e-6
@@ -46,11 +43,8 @@ def test_model_solver(self):
             )
             self.assertEqual(solution.termination, "final time")
 
-            t0 = time.perf_counter()
             second_solution = solver.solve(model, t_eval)
-            t_second_solve = time.perf_counter() - t0
 
-            self.assertLess(t_second_solve, t_first_solve)
             np.testing.assert_array_equal(second_solution.y, solution.y)
 
     def test_semi_explicit_model(self):
@@ -75,9 +69,7 @@ def test_semi_explicit_model(self):
         # Solve
         solver = pybamm.JaxSolver(method="BDF", rtol=1e-8, atol=1e-8)
         t_eval = np.linspace(0, 1, 80)
-        t0 = time.perf_counter()
         solution = solver.solve(model, t_eval)
-        t_first_solve = time.perf_counter() - t0
         np.testing.assert_array_equal(solution.t, t_eval)
         soln = np.exp(0.1 * solution.t)
         np.testing.assert_allclose(solution.y[0], soln, rtol=1e-7, atol=1e-7)
@@ -89,11 +81,7 @@ def test_semi_explicit_model(self):
         )
         self.assertEqual(solution.termination, "final time")
 
-        t0 = time.perf_counter()
         second_solution = solver.solve(model, t_eval)
-        t_second_solve = time.perf_counter() - t0
-
-        self.assertLess(t_second_solve, t_first_solve)
         np.testing.assert_array_equal(second_solution.y, solution.y)
 
     def test_solver_sensitivities(self):
@@ -205,25 +193,18 @@ def test_model_solver_with_inputs(self):
         # Solve
         solver = pybamm.JaxSolver(rtol=1e-8, atol=1e-8)
         t_eval = np.linspace(0, 5, 80)
-
-        t0 = time.perf_counter()
         solution = solver.solve(model, t_eval, inputs={"rate": 0.1})
-        t_first_solve = time.perf_counter() - t0
 
         np.testing.assert_allclose(
             solution.y[0], np.exp(-0.1 * solution.t), rtol=1e-6, atol=1e-6
         )
 
-        t0 = time.perf_counter()
         solution = solver.solve(model, t_eval, inputs={"rate": 0.2})
-        t_second_solve = time.perf_counter() - t0
 
         np.testing.assert_allclose(
             solution.y[0], np.exp(-0.2 * solution.t), rtol=1e-6, atol=1e-6
         )
 
-        self.assertLess(t_second_solve, t_first_solve)
-
     def test_get_solve(self):
         # Create model
         model = pybamm.BaseModel()