TIME-X Test Hackathon @ TUD: Test for SwitchEstimator (#404)

* Added piecewise linear interpolation to SwitchEstimator

* Started with test for SwitchEstimator [WIP]

* Test to proof sum_restarts when event occuring at boundary

* Started with test to check adapt_interpolation_info [WIP]

* Added test for SE.adapt_interpolation_info()

* Update linear interpolation + logging + changing tolerances

* Test for linear interpolation + update of other test

* Correction for finite difference + adaption tolerance

* Added test for DAE case for SE

* Choice of FD seems to be important for performance of SE

* Removed attributes from dummy probs (since the parent classes have it)

* Test for dummy problems + using functions from battery_model.py

* Moved standard params for test to function

* Updated hardcoded solutions for battery models

* Updated hardcoded solutions for DiscontinuousTestODE

* Updated docu in SE for FDs

* Lagrange Interpolation works better with baclward FD and alpha=0.9

* Added test for state function + global error

* Updated LogEvent hooks

* Updated hardcoded solutions again

* Adapted test_problems.py

* Minor changes

* Updated tests

* Speed-up test for buck converter

* Black..

* Use msg about convergence info in Newton in SE

* Moved dummy problem to file

* Speed up loop using mask

* Removed loop

pySDC/implementations/problem_classes/DiscontinuousTestODE.py

@@ -214,11 +214,72 @@ def get_switching_info(self, u, t):
                 m_guess = m - 1
                 break
 
-        state_function = [u[m][0] - 5 for m in range(len(u))] if switch_detected else []
+        state_function = [u[m][0] - 5 for m in range(len(u))]
         return switch_detected, m_guess, state_function
 
     def count_switches(self):
         """
         Setter to update the number of switches if one is found.
         """
         self.nswitches += 1
+
+
+class ExactDiscontinuousTestODE(DiscontinuousTestODE):
+    r"""
+    Dummy ODE problem for testing the ``SwitchEstimator`` class. The problem contains the exact dynamics
+    of the problem class ``DiscontinuousTestODE``.
+    """
+
+    def __init__(self, newton_maxiter=100, newton_tol=1e-8):
+        """Initialization routine"""
+        super().__init__(newton_maxiter, newton_tol)
+
+    def eval_f(self, u, t):
+        """
+        Derivative.
+
+        Parameters
+        ----------
+        u : dtype_u
+            Exact value of u.
+        t : float
+            Time :math:`t`.
+
+        Returns
+        -------
+        f : dtype_f
+            Derivative.
+        """
+
+        f = self.dtype_f(self.init)
+
+        t_switch = np.inf if self.t_switch is None else self.t_switch
+        h = u[0] - 5
+        if h >= 0 or t >= t_switch:
+            f[:] = 1
+        else:
+            f[:] = np.exp(t)
+        return f
+
+    def solve_system(self, rhs, factor, u0, t):
+        """
+        Just return the exact solution...
+
+        Parameters
+        ----------
+        rhs : dtype_f
+            Right-hand side for the linear system.
+        factor : float
+            Abbrev. for the local stepsize (or any other factor required).
+        u0 : dtype_u
+            Initial guess for the iterative solver.
+        t : float
+            Current time (e.g. for time-dependent BCs).
+
+        Returns
+        -------
+        me : dtype_u
+            The solution as mesh.
+        """
+
+        return self.u_exact(t)

pySDC/projects/PinTSimE/battery_model.py

@@ -167,10 +167,13 @@ def generateDescription(
         'convergence_controllers': convergence_controllers,
     }
 
-    return description, controller_params
+    # instantiate controller
+    controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
+
+    return description, controller_params, controller
 
 
-def controllerRun(description, controller_params, t0, Tend, exact_event_time_avail=False):
+def controllerRun(description, controller_params, controller, t0, Tend, exact_event_time_avail=False):
     """
     Executes a controller run for a problem defined in the description.
 
@@ -180,6 +183,8 @@ def controllerRun(description, controller_params, t0, Tend, exact_event_time_ava
         Contains all information for a controller run.
     controller_params : dict
         Parameters needed for a controller run.
+    controller : pySDC.core.Controller
+        Controller to do the stuff.
     t0 : float
         Starting time of simulation.
     Tend : float
@@ -193,9 +198,6 @@ def controllerRun(description, controller_params, t0, Tend, exact_event_time_ava
         Raw statistics from a controller run.
     """
 
-    # instantiate controller
-    controller = controller_nonMPI(num_procs=1, controller_params=controller_params, description=description)
-
     # get initial values on finest level
     P = controller.MS[0].levels[0].prob
     uinit = P.u_exact(t0)
@@ -233,7 +235,7 @@ def main():
         'max_restarts': 50,
         'recomputed': False,
         'tol_event': 1e-10,
-        'alpha': 1.0,
+        'alpha': 0.96,
         'exact_event_time_avail': None,
     }
 
@@ -244,8 +246,8 @@ def main():
 
     hook_class = [LogSolution, LogEventBattery, LogEmbeddedErrorEstimate, LogStepSize]
 
-    use_detection = [True]
-    use_adaptivity = [True]
+    use_detection = [True, False]
+    use_adaptivity = [True, False]
 
     for problem, sweeper in zip([battery, battery_implicit], [imex_1st_order, generic_implicit]):
         for defaults in [False, True]:
@@ -360,7 +362,7 @@ def runSimulation(problem, sweeper, all_params, use_adaptivity, use_detection, h
 
                     restol = -1 if use_A else handling_params['restol']
 
-                    description, controller_params = generateDescription(
+                    description, controller_params, controller = generateDescription(
                         dt=dt,
                         problem=problem,
                         sweeper=sweeper,
@@ -381,6 +383,7 @@ def runSimulation(problem, sweeper, all_params, use_adaptivity, use_detection, h
                     stats, t_switch_exact = controllerRun(
                         description=description,
                         controller_params=controller_params,
+                        controller=controller,
                         t0=interval[0],
                         Tend=interval[-1],
                         exact_event_time_avail=handling_params['exact_event_time_avail'],

pySDC/projects/PinTSimE/buck_model.py

@@ -55,7 +55,7 @@ def main():
         use_adaptivity=use_adaptivity,
         use_detection=use_detection,
         hook_class=hook_class,
-        interval=(0.0, 2e-2),
+        interval=(0.0, 1e-2),
         dt_list=[1e-5, 2e-5],
         nnodes=[M_fix],
     )

pySDC/projects/PinTSimE/discontinuous_test_ODE.py

@@ -68,8 +68,9 @@ def main():
         'max_restarts': 50,
         'recomputed': False,
         'tol_event': 1e-12,
-        'alpha': 1.0,
+        'alpha': 0.96,
         'exact_event_time_avail': True,
+        'typeFD': 'backward',
     }
 
     # ---- all parameters are stored in this dictionary ----

pySDC/projects/PinTSimE/estimation_check.py

@@ -45,7 +45,7 @@ def run_estimation_check():
         'max_restarts': 50,
         'recomputed': False,
         'tol_event': 1e-10,
-        'alpha': 1.0,
+        'alpha': 0.96,
         'exact_event_time_avail': None,
     }
 
@@ -114,7 +114,7 @@ def run_estimation_check():
 
         plotAccuracyCheck(u_num, prob_cls_name, M_fix)
 
-        plotStateFunctionAroundEvent(u_num, prob_cls_name, M_fix)
+        # plotStateFunctionAroundEvent(u_num, prob_cls_name, M_fix)
 
         plotStateFunctionOverTime(u_num, prob_cls_name, M_fix)
 
@@ -187,6 +187,9 @@ def plotStateFunctionAroundEvent(u_num, prob_cls_name, M_fix):  # pragma: no cov
     Routine that plots the state function at time before the event, exactly at the event, and after the event. Note
     that this routine does make sense only for a state function that remains constant after the event.
 
+    TODO: Function still does not work as expected. Every time when the switch estimator is adapted, the tolerances
+    does not suit anymore!
+
     Parameters
     ----------
     u_num : dict
@@ -239,15 +242,18 @@ def plotStateFunctionAroundEvent(u_num, prob_cls_name, M_fix):  # pragma: no cov
 
                     if use_SE:
                         t_switches = [u_num[dt][M_fix][use_SE][use_A]['t_switches'] for dt in dt_list]
-                        t_switch = [t_event[i] for t_event in t_switches]
+                        for t_switch_item in t_switches:
+                            mask = np.append([True], np.abs(t_switch_item[1:] - t_switch_item[:-1]) > 1e-10)
+                            t_switch_item = t_switch_item[mask]
 
+                        t_switch = [t_event[i] for t_event in t_switches]
                         ax[0, ind].plot(
                             dt_list,
                             [
                                 h_item[m]
                                 for (t_item, h_item, t_switch_item) in zip(t, h, t_switch)
                                 for m in range(len(t_item))
-                                if abs(t_item[m] - t_switch_item) <= 1e-14
+                                if abs(t_item[m] - t_switch_item) <= 2.7961188919789493e-11
                             ],
                             color='limegreen',
                             marker='s',