added correct errors

dwhswenson · Aug 23, 2016 · Aug 13, 2016 · Aug 13, 2016 · Aug 13, 2016 · Aug 14, 2016
commit a0bf940f07411358660cae67ffd4aba7d2e2644d
diff --git a/openpathsampling/engines/__init__.py b/openpathsampling/engines/__init__.py
@@ -5,4 +5,6 @@
 
 import features
 
-from dynamics_engine import DynamicsEngine, NoEngine
+from dynamics_engine import (
+    DynamicsEngine, NoEngine, EngineError,
+    EngineNaNError, EngineMaxLengthError)
diff --git a/openpathsampling/engines/dynamics_engine.py b/openpathsampling/engines/dynamics_engine.py
@@ -27,9 +27,24 @@
 
 
 # =============================================================================
-# Multi-State Transition Interface Sampling
+# Base dynamics engine class
 # =============================================================================
 
+class EngineError(Exception):
+    def __init__(self, message, last_trajectory):
+        # Call the base class constructor with the parameters it needs
+        super(EngineError, self).__init__(message)
+
+        # Now for your custom code...
+        self.last_trajectory = last_trajectory
+
+class EngineMaxLengthError(EngineError):
+    pass
+
+
+class EngineNaNError(EngineError):
+    pass
+
 
 class DynamicsEngine(StorableNamedObject):
     """
@@ -525,9 +540,10 @@ def iter_generate(self, initial, running=None, direction=+1,
                     on = self.on_max_length
 
                     if on == 'fail':
-                        final_error = RuntimeError(
+                        final_error = EngineMaxLengthError(
                             'Hit maximal length of %d frames.' %
-                            self.options['n_frames_max']
+                            self.options['n_frames_max'],
+                            trajectory
                         )
                         break
                     elif on == 'ignore':
@@ -541,27 +557,41 @@ def iter_generate(self, initial, running=None, direction=+1,
                         attempt_max_length += 1
                         if attempt_max_length > self.retries_when_max_length:
                             if self.on_nan == 'fail':
-                                final_error = RuntimeError(
+                                final_error = EngineMaxLengthError(
                                     'Failed to generate trajectory without '
                                     'hitting max length after %d attempts' %
-                                    attempt_max_length)
+                                    attempt_max_length,
+                                    trajectory)
                                 break
 
             if has_nan:
-                attempt_nan += 1
-                if attempt_nan > self.retries_when_nan:
-                    if self.on_nan == 'fail':
-                        final_error = RuntimeError(
+                on = self.on_nan
+                if on == 'fail':
+                    final_error = EngineNaNError('`nan` in snapshot')
+                elif on == 'retry':
+                    attempt_nan += 1
+                    if attempt_nan > self.retries_when_nan:
+                        final_error = EngineNaNError(
                             'Failed to generate trajectory without `nan` '
-                            'after %d attempts' % attempt_nan)
+                            'after %d attempts' % attempt_error,
+                            trajectory)
+                elif on == 'ignore':
+                    pass
 
             if has_error:
-                attempt_error += 1
-                if attempt_error > self.retries_when_nan:
-                    if self.on_error == 'fail':
+                on = self.on_nan
+                if on == 'fail':
+                    final_error = errors[-1]
+                    del errors[-1]
+                elif on == 'retry':
+                    attempt_error += 1
+                    if attempt_error > self.retries_when_error:
                         final_error = RuntimeError(
-                            'Failed to generate trajectory without error '
-                            'after %d attempts' % attempt_error)
+                            'Failed to generate trajectory without `nan` '
+                            'after %d attempts' % attempt_error,
+                            trajectory)
+                elif on == 'ignore':
+                    pass
 
             elif stop:
                 valid = True

diff --git a/openpathsampling/pathmover.py b/openpathsampling/pathmover.py
@@ -626,6 +626,16 @@ def move(self, replica_state):
         return ReplicaState(d.items())
 
 
+class SampleNaNError(Exception):
+    def __init__(self, message, trial_sample):
+        super(SampleNaNError, self).__init__(message)
+        self.trial_sample = trial_sample
+
+
+class MoveChangeNaNError(Exception):
+    pass
+
+
 class PathMover(TreeMixin, StorableNamedObject):
     """
     A PathMover is the description of a move in replica space.
@@ -1104,8 +1114,16 @@ def move(self, sample_set):
         # 2. pick samples from these ensembles
         samples = [self.select_sample(sample_set, ens) for ens in ensembles]
 
-        # 3. pass these samples to the generator
-        trials = self(*samples)
+        try:
+            # 3. pass these samples to the generator
+            trials = self(*samples)
+        except SampleNaNError as e:
+            return paths.RejectedSampleMoveChange(
+                samples=e.trial_sample,
+                mover=self,
+                details=paths.MoveDetails(
+                    error='NaN')
+            )
 
         # 4. accept/reject
         accepted, details = self._accept(trials)
@@ -1124,6 +1142,7 @@ def move(self, sample_set):
                 details=details
             )
 
+
     @abc.abstractmethod
     def __call__(self, *args):
         """Generate trial samples directly
@@ -1197,7 +1216,27 @@ def __call__(self, input_sample):
 
         shooting_index = self.selector.pick(initial_trajectory)
 
-        trial_trajectory = self._run(initial_trajectory, shooting_index)
+        try:
+            trial_trajectory = self._run(initial_trajectory, shooting_index)
+        except paths.engines.EngineError as e:
+            trial_trajectory = e.last_trajectory
+
+            trial_details = paths.SampleDetails(
+                initial_trajectory=initial_trajectory,
+                shooting_snapshot=initial_trajectory[shooting_index],
+                error='NaN'
+            )
+
+            trial = paths.Sample(
+                replica=replica,
+                trajectory=trial_trajectory,
+                ensemble=self.target_ensemble,
+                parent=input_sample,
+                details=trial_details,
+                mover=self
+            )
+
+            raise SampleNaNError('Sample with NaN', trial)
 
         bias = self.selector.probability_ratio(
             initial_trajectory[shooting_index],