further playing around

Author: pancetta

pySDC/implementations/problem_classes/HeatEquation_1D_FD.py

@@ -114,8 +114,9 @@ def u_exact(self, t):
         me = self.dtype_u(self.init)
         if self.params.freq >= 0:
             xvalues = np.array([(i + 1) * self.dx for i in range(self.params.nvars)])
+            rho = (2.0 - 2.0 * np.cos(np.pi * self.params.freq * self.dx)) / self.dx ** 2
             me.values = np.sin(np.pi * self.params.freq * xvalues) * \
-                np.exp(-t * self.params.nu * (np.pi * self.params.freq) ** 2)
+                np.exp(-t * self.params.nu * rho)
         else:
             np.random.seed(1)
             me.values = np.random.rand(self.params.nvars)

pySDC/playgrounds/order_test/heat1d.py

@@ -11,8 +11,11 @@
 from pySDC.implementations.controller_classes.allinclusive_multigrid_nonMPI import allinclusive_multigrid_nonMPI
 from pySDC.implementations.problem_classes.HeatEquation_1D_FD_periodic import heat1d_periodic
 from pySDC.implementations.problem_classes.HeatEquation_1D_FD_forced import heat1d_forced
+from pySDC.implementations.problem_classes.HeatEquation_1D_FD import heat1d
 from pySDC.implementations.transfer_classes.TransferMesh import mesh_to_mesh
 
+from pySDC.playgrounds.order_test.hook_get_update import get_update
+
 from pySDC.helpers.stats_helper import filter_stats, sort_stats
 
 
@@ -28,32 +31,33 @@ def main():
 
     # This comes as read-in for the problem class
     problem_params = dict()
-    problem_params['nu'] = 0.01
+    problem_params['nu'] = 0.1
     problem_params['freq'] = 2
-    problem_params['nvars'] = [2 ** 7, 2 ** 6]
+    problem_params['nvars'] = [2 ** 10 - 1, 2 ** 9 - 1]
 
     # This comes as read-in for the sweeper class
     sweeper_params = dict()
     sweeper_params['collocation_class'] = CollGaussRadau_Right
     sweeper_params['num_nodes'] = [5]
-    sweeper_params['QI'] = ['IE', 'PIC']
+    sweeper_params['QI'] = ['IE']#, 'IE']
     sweeper_params['spread'] = False
     sweeper_params['do_coll_update'] = False
 
     # initialize space transfer parameters
     space_transfer_params = dict()
     space_transfer_params['rorder'] = 2
     space_transfer_params['iorder'] = 6
-    space_transfer_params['periodic'] = True
+    space_transfer_params['periodic'] = False
 
     # initialize controller parameters
     controller_params = dict()
-    controller_params['logger_level'] = 20
+    controller_params['logger_level'] = 30
     controller_params['predict'] = False
+    # controller_params['hook_class'] = get_update
 
     # Fill description dictionary for easy hierarchy creation
     description = dict()
-    description['problem_class'] = heat1d_periodic
+    description['problem_class'] = heat1d
     description['dtype_u'] = mesh
     description['dtype_f'] = mesh#rhs_imex_mesh
     description['sweeper_class'] = generic_implicit#imex_1st_order
@@ -69,8 +73,8 @@ def main():
     t0 = 0.0
     Tend = 1.0
 
-    dt_list = [Tend / 2 ** i for i in range(0, 6)]
-    niter_list = [100]#[1, 2, 3, 4]
+    dt_list = [Tend / 2 ** i for i in range(0, 8)]
+    niter_list = [2]#[1, 2, 3, 4]
 
     for niter in niter_list:
 
@@ -104,7 +108,7 @@ def main():
             print('   error at time %s: %s' % (Tend, err_new))
             if err > 0:
                 print('   order of accuracy: %6.4f' % (np.log(err / err_new) / np.log(2)))
-
+            # exit()
             err = err_new
 
             # # filter statistics by type (number of iterations)

pySDC/playgrounds/order_test/hook_get_update.py

@@ -0,0 +1,37 @@
+from pySDC.core.Hooks import hooks
+
+
+class get_update(hooks):
+
+    def pre_iteration(self, step, level_number):
+        """
+        Hook called before each step
+
+        Args:
+            step (pySDC.Step.step): the current step
+            level_number (int): the current level number
+        """
+        super(get_update, self).pre_iteration(step, level_number)
+
+        L = step.levels[level_number]
+        L.sweep.compute_end_point()
+
+        L.uold = L.uend
+
+    def post_iteration(self, step, level_number):
+        """
+        Hook called before each step
+
+        Args:
+            step (pySDC.Step.step): the current step
+            level_number (int): the current level number
+        """
+        super(get_update, self).post_iteration(step, level_number)
+
+        L = step.levels[level_number]
+        L.sweep.compute_end_point()
+
+        uex = L.prob.u_exact(L.time + L.dt)
+        err_new = abs(uex - L.uend)
+
+        print(abs(L.uold - L.uend), err_new)