Merge pull request #2809 from emma58/reversible-fix-disjunctive-logic

Adding (reversible) `gdp.transform_current_disjunctive_logic` transformation

pyomo/core/__init__.py

@@ -189,7 +189,11 @@
     ConcreteModel,
     AbstractModel,
 )
-from pyomo.core.base.transformation import Transformation, TransformationFactory
+from pyomo.core.base.transformation import (
+    Transformation,
+    TransformationFactory,
+    ReverseTransformationToken,
+)
 
 from pyomo.core.base.instance2dat import instance2dat
 

pyomo/core/base/__init__.py

@@ -135,7 +135,11 @@
     ConcreteModel,
     AbstractModel,
 )
-from pyomo.core.base.transformation import Transformation, TransformationFactory
+from pyomo.core.base.transformation import (
+    Transformation,
+    TransformationFactory,
+    ReverseTransformationToken,
+)
 
 from pyomo.core.base.instance2dat import instance2dat
 

pyomo/core/base/transformation.py

@@ -10,6 +10,8 @@
 #  ___________________________________________________________________________
 
 from pyomo.common import Factory
+from pyomo.common.collections import ComponentSet
+from pyomo.common.errors import MouseTrap
 from pyomo.common.deprecation import deprecated
 from pyomo.common.modeling import unique_component_name
 from pyomo.common.timing import TransformationTimer
@@ -72,9 +74,11 @@ def apply_to(self, model, **kwds):
         timer = TransformationTimer(self, 'in-place')
         if not hasattr(model, '_transformation_data'):
             model._transformation_data = TransformationData()
-        self._apply_to(model, **kwds)
+        reverse_token = self._apply_to(model, **kwds)
         timer.report()
 
+        return reverse_token
+
     def create_using(self, model, **kwds):
         """
         Create a new model with this transformation
@@ -105,6 +109,63 @@ def _create_using(self, model, **kwds):
         return instance
 
 
+class ReverseTransformationToken(object):
+    """
+    Class returned by reversible transformations' apply_to methods that
+    can be passed back to the transformation in order to revert its changes
+    to the model.
+
+    We store the transformation that created it, so that we have some basic
+    error checking when the user attempts to revert, and we store a dictionary
+    that can be whatever the transformation wants/needs in order to revert
+    itself.
+
+    args:
+        transformation: The class of the transformation that created this token
+        model: The model being transformed when this token was created
+        targets: The targets on 'model' being transformed when this token
+                 was created.
+        reverse_dict: Dictionary with everything the transformation needs to
+                      undo itself.
+    """
+
+    def __init__(self, transformation, model, targets, reverse_dict):
+        self._transformation = transformation
+        self._model = model
+        self._targets = ComponentSet(targets)
+        self._reverse_dict = reverse_dict
+
+    @property
+    def transformation(self):
+        return self._transformation
+
+    @property
+    def reverse_dict(self):
+        return self._reverse_dict
+
+    def check_token_valid(self, cls, model, targets):
+        if cls is not self._transformation:
+            raise ValueError(
+                "Attempting to reverse transformation of class '%s' "
+                "using a token created by a transformation of class "
+                "'%s'. Cannot revert transformation with a token from "
+                "another transformation." % (cls, self._transformation)
+            )
+        if model is not self._model:
+            raise MouseTrap(
+                "A reverse transformation was called on model '%s', but the "
+                "transformation that created this token was created from "
+                "model '%s'. We do not currently support reversing "
+                "transformations on clones of the transformed model."
+                % (model.name, self._model.name)
+            )
+        # TODO: Do we need to pass targets into this? I'm thinking no because
+        # people can untransform selectively. We just need to enforce that the
+        # targets given here were indeed transformed, but they don't have to
+        # correspond exactly to what happened before. I think we leave that for
+        # the transformation to sort out
+
+
 TransformationFactory = Factory('transformation type')
 
 

pyomo/dae/plugins/colloc.py

@@ -462,8 +462,6 @@ def _apply_to(self, instance, **kwds):
 
         self._transformBlock(instance, currentds)
 
-        return instance
-
     def _transformBlock(self, block, currentds):
         self._fe = {}
         for ds in block.component_objects(ContinuousSet, descend_into=True):

pyomo/dae/plugins/finitedifference.py

@@ -237,8 +237,6 @@ def _apply_to(self, instance, **kwds):
 
         self._transformBlock(instance, currentds)
 
-        return instance
-
     def _transformBlock(self, block, currentds):
         self._fe = {}
         for ds in block.component_objects(ContinuousSet):

pyomo/gdp/plugins/__init__.py

@@ -20,4 +20,5 @@ def load():
     import pyomo.gdp.plugins.partition_disjuncts
     import pyomo.gdp.plugins.between_steps
     import pyomo.gdp.plugins.multiple_bigm
+    import pyomo.gdp.plugins.transform_current_disjunctive_state
     import pyomo.gdp.plugins.bound_pretransformation

pyomo/gdp/plugins/fix_disjuncts.py

@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2022
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Transformation to fix and enforce disjunct True/False status."""
 

pyomo/gdp/plugins/gdp_to_mip_transformation.py

@@ -100,8 +100,8 @@ def _restore_state(self):
     def _process_arguments(self, instance, **kwds):
         if not instance.ctype in (Block, Disjunct):
             raise GDP_Error(
-                "Transformation called on %s of type %s. 'instance'"
-                " must be a ConcreteModel, Block, or Disjunct (in "
+                "Transformation called on %s of type %s. 'instance' "
+                "must be a ConcreteModel, Block, or Disjunct (in "
                 "the case of nested disjunctions)." % (instance.name, instance.ctype)
             )
 
@@ -145,8 +145,8 @@ def _filter_inactive(targets):
             for t in targets:
                 if not t.active:
                     self.logger.warning(
-                        'GDP.Hull transformation passed a deactivated '
-                        f'target ({t.name}). Skipping.'
+                        f'GDP.{self.transformation_name} transformation passed '
+                        f'a deactivated target ({t.name}). Skipping.'
                     )
                 else:
                     yield t