Always use collocation formulation to compute uend. This fixes #52.

Author: pancetta

pySDC/sweeper_classes/boris_2nd_order.py

@@ -174,29 +174,23 @@ def compute_end_point(self):
         """
         Compute u at the right point of the interval
 
-        The value uend computed here might be a simple copy from u[M] (if right point is a collocation node) or
-        a full evaluation of the Picard formulation (if right point is not a collocation node)
+        The value uend computed here is a full evaluation of the Picard formulation (always!)
         """
 
         # get current level and problem description
         L = self.level
         P = L.prob
 
-        # check if Mth node is equal to right point (flag is set in collocation class)
-        if self.coll.right_is_node:
-            # a copy is sufficient
-            L.uend = P.dtype_u(L.u[-1])
-        else:
-            # start with u0 and add integral over the full interval (using coll.weights)
-            L.uend = P.dtype_u(L.u[0])
-            # compute q*Q on the fly.. could be done a priori (fixme)
-            qQ = np.dot(self.coll.weights,self.coll.Qmat[1:,1:])
-            for m in range(self.coll.num_nodes):
-                f = P.build_f(L.f[m+1],L.u[m+1],L.time+L.dt*self.coll.nodes[m])
-                L.uend.pos += L.dt*(L.dt*qQ[m]*f) + L.dt*self.coll.weights[m]*L.u[0].vel
-                L.uend.vel += L.dt*self.coll.weights[m]*f
-            # add up tau correction of the full interval (last entry)
-            if L.tau is not None:
-                L.uend += L.tau[-1]
+        # start with u0 and add integral over the full interval (using coll.weights)
+        L.uend = P.dtype_u(L.u[0])
+        # compute q*Q on the fly.. could be done a priori (fixme)
+        qQ = np.dot(self.coll.weights,self.coll.Qmat[1:,1:])
+        for m in range(self.coll.num_nodes):
+            f = P.build_f(L.f[m+1],L.u[m+1],L.time+L.dt*self.coll.nodes[m])
+            L.uend.pos += L.dt*(L.dt*qQ[m]*f) + L.dt*self.coll.weights[m]*L.u[0].vel
+            L.uend.vel += L.dt*self.coll.weights[m]*f
+        # add up tau correction of the full interval (last entry)
+        if L.tau is not None:
+            L.uend += L.tau[-1]
 
         return None

pySDC/sweeper_classes/generic_LU.py

@@ -128,25 +128,19 @@ def compute_end_point(self):
         """
         Compute u at the right point of the interval
 
-        The value uend computed here might be a simple copy from u[M] (if right point is a collocation node) or
-        a full evaluation of the Picard formulation (if right point is not a collocation node)
+        The value uend computed here is a full evaluation of the Picard formulation (always!)
         """
 
         # get current level and problem description
         L = self.level
         P = L.prob
 
-        # check if Mth node is equal to right point (flag is set in collocation class)
-        if self.coll.right_is_node:
-            # a copy is sufficient
-            L.uend = P.dtype_u(L.u[-1])
-        else:
-            # start with u0 and add integral over the full interval (using coll.weights)
-            L.uend = P.dtype_u(L.u[0])
-            for m in range(self.coll.num_nodes):
-                L.uend += L.dt*self.coll.weights[m]*L.f[m+1]
-            # add up tau correction of the full interval (last entry)
-            if L.tau is not None:
-                L.uend += L.tau[-1]
+        # start with u0 and add integral over the full interval (using coll.weights)
+        L.uend = P.dtype_u(L.u[0])
+        for m in range(self.coll.num_nodes):
+            L.uend += L.dt*self.coll.weights[m]*L.f[m+1]
+        # add up tau correction of the full interval (last entry)
+        if L.tau is not None:
+            L.uend += L.tau[-1]
 
         return None

pySDC/sweeper_classes/imex_1st_order.py

@@ -134,25 +134,19 @@ def compute_end_point(self):
         """
         Compute u at the right point of the interval
 
-        The value uend computed here might be a simple copy from u[M] (if right point is a collocation node) or
-        a full evaluation of the Picard formulation (if right point is not a collocation node)
+        The value uend computed here is a full evaluation of the Picard formulation (always!)
         """
 
         # get current level and problem description
         L = self.level
         P = L.prob
 
-        # check if Mth node is equal to right point (flag is set in collocation class)
-        if self.coll.right_is_node:
-            # a copy is sufficient
-            L.uend = P.dtype_u(L.u[-1])
-        else:
-            # start with u0 and add integral over the full interval (using coll.weights)
-            L.uend = P.dtype_u(L.u[0])
-            for m in range(self.coll.num_nodes):
-                L.uend += L.dt*self.coll.weights[m]*(L.f[m+1].impl + L.f[m+1].expl)
-            # add up tau correction of the full interval (last entry)
-            if L.tau is not None:
-                L.uend += L.tau[-1]
+        # start with u0 and add integral over the full interval (using coll.weights)
+        L.uend = P.dtype_u(L.u[0])
+        for m in range(self.coll.num_nodes):
+            L.uend += L.dt*self.coll.weights[m]*(L.f[m+1].impl + L.f[m+1].expl)
+        # add up tau correction of the full interval (last entry)
+        if L.tau is not None:
+            L.uend += L.tau[-1]
 
         return None

tests/test_imexsweeper.py

@@ -121,9 +121,6 @@ def test_sweepequalmatrix(self):
   #
   def test_updateformula(self):
 
-    if (self.swparams['collocation_class']==collclass.CollGaussLobatto):
-      raise unittest.SkipTest("Needs fix of issue #52 before passing for Gauss Lobatto nodes")
-
     step, level, problem, nnodes = self.setupLevelStepProblem()
     level.sweep.predict()
     u0full = np.array([ level.u[l].values.flatten() for l in range(1,nnodes+1) ])
@@ -209,9 +206,6 @@ def test_manysweepsequalmatrix(self):
   #
   def test_maysweepupdate(self):
 
-    if (self.swparams['collocation_class']==collclass.CollGaussLobatto):
-      raise unittest.SkipTest("Needs fix of issue #52 before passing for Gauss Lobatto nodes")
-
     step, level, problem, nnodes = self.setupLevelStepProblem()
     step.levels[0].sweep.predict()
     u0full = np.array([ level.u[l].values.flatten() for l in range(1,nnodes+1) ])