hannah
5 years ago
committed by
Matthias Volk
No known key found for this signature in database
GPG Key ID: 83A57678F739FCD3
5 changed files with 197 additions and 5 deletions
-
3doc/source/advanced_topics.rst
-
122doc/source/doc/building_ctmcs.rst
-
10doc/source/doc/building_dtmcs.rst
-
34doc/source/doc/building_mas.rst
-
33doc/source/doc/building_mdps.rst
@ -0,0 +1,122 @@ |
|||
************************************** |
|||
Continuous-time Markov chains (CTMCs) |
|||
************************************** |
|||
|
|||
|
|||
Background |
|||
===================== |
|||
|
|||
In this section, we explain how Stormpy can be used to build a CTMC representing a cyclic server polling system. |
|||
Building CTMCs works similar to building DTMCs as in :doc:`building_dtmcs`, but additionally every state is equipped with an exit rate. |
|||
|
|||
.. seealso:: `01-building-ctmcs.py <todo /examples/building_ctmcs/01-building-ctmcs.py>` |
|||
|
|||
First, we import Stormpy:: |
|||
|
|||
>>> import stormpy |
|||
|
|||
Transition Matrix |
|||
===================== |
|||
We build the transition matrix using numpy. As an alternative, the SparseMatrixBuilder can be used here:: |
|||
|
|||
>>> import numpy as np |
|||
|
|||
>>> transitions = np.array([ |
|||
... [0, 0.5, 0.5, 200, 0, 0, 0, 0, 0, 0, 0, 0], |
|||
... [0, 0, 0, 0, 0.5, 200, 0, 0, 0, 0, 0, 0], |
|||
... [0, 0, 0, 0, 0.5, 0, 200, 0, 0, 0, 0, 0], |
|||
... [200, 0, 0, 0, 0, 0, 0.5, 0.5, 0, 0, 0, 0], |
|||
... [0, 0, 0, 0, 0, 0, 0, 0, 200, 0, 0, 0], |
|||
... [0, 0, 0, 1, 0, 0, 0, 0, 0.5, 0, 0, 0], |
|||
... [0, 0, 0, 0, 0, 0, 0, 0, 0, 0.5, 200, 0], |
|||
... [0, 200, 0, 0, 0, 0, 0, 0, 0, 0.5, 0, 0], |
|||
... [0, 0, 0, 0, 0, 0, 1, 0, 0, 0 ,0, 0], |
|||
... [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 200], |
|||
... [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0.5 ], |
|||
... [0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]], dtype='float64') |
|||
|
|||
We do not specify the row_group_indices. Thus, the following function call returns a sparse matrix with default row groups.:: |
|||
|
|||
>>> transition_matrix = stormpy.build_sparse_matrix(transitions) |
|||
|
|||
Labeling |
|||
================ |
|||
Next, we create the state labeling:: |
|||
|
|||
>>> state_labeling = stormpy.storage.StateLabeling(12) |
|||
>>> state_labels = {'init', 'deadlock', 'target'} |
|||
>>> for label in state_labels: |
|||
... state_labeling.add_label(label) |
|||
>>> state_labeling.add_label_to_state('init', 0) |
|||
>>> state_labeling.set_states('target', stormpy.BitVector(12, [5, 8])) |
|||
|
|||
For the choice labeling this works similar:: |
|||
|
|||
>>> nr_choices = 12 |
|||
>>> choice_labeling = stormpy.storage.ChoiceLabeling(nr_choices) |
|||
>>> choice_labels = {'loop1a', 'loop1b', 'serve1', 'loop2a', 'loop2b', 'serve2'} |
|||
>>> for label in choice_labels: |
|||
... choice_labeling.add_label(label) |
|||
|
|||
To set the same label for multiple choices, we can use a BitVector:: |
|||
|
|||
>>> choice_labeling.set_choices('loop1a', stormpy.BitVector(nr_choices, [0, 2])) |
|||
>>> choice_labeling.set_choices('loop1b', stormpy.BitVector(nr_choices, [1, 4])) |
|||
>>> choice_labeling.set_choices('serve1', stormpy.BitVector(nr_choices, [5, 8])) |
|||
>>> choice_labeling.set_choices('loop2a', stormpy.BitVector(nr_choices, [3, 7])) |
|||
>>> choice_labeling.set_choices('loop2b', stormpy.BitVector(nr_choices, [6, 9])) |
|||
>>> choice_labeling.set_choices('serve2', stormpy.BitVector(nr_choices, [10, 11])) |
|||
|
|||
Reward models |
|||
================== |
|||
|
|||
Now, we create the reward models, beginning with the reward model named 'served' which has state-action rewards:: |
|||
|
|||
>>> reward_models = {} |
|||
>>> action_reward = [0.0, 0.0, 0.0, 0.0, 0.0, 2/3, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0] |
|||
>>> reward_models['served'] = stormpy.SparseRewardModel(optional_state_action_reward_vector = action_reward) |
|||
|
|||
In the same way we can create a second reward model. This time we consider state rewards:: |
|||
|
|||
>>> state_reward = [0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0] |
|||
>>> reward_models['waiting'] = stormpy.SparseRewardModel(optional_state_reward_vector = state_reward) |
|||
|
|||
Exit Rates |
|||
==================== |
|||
Lastly, we equip every state with an exit rate:: |
|||
|
|||
>>> exit_rates = [201.0, 200.5, 200.5, 201.0, 200.0, 1.5, 200.5, 200.5, 1.0, 200.0, 1.5, 1.0] |
|||
|
|||
Building the Model |
|||
==================== |
|||
|
|||
Now, we can collect all components, including the choice labeling and the exit rates. |
|||
To let the transition values be interpreted as rates we set rate_transitions to True:: |
|||
|
|||
>>> components = stormpy.SparseModelComponents(transition_matrix=transition_matrix, state_labeling=state_labeling, reward_models=reward_models, rate_transitions = True) |
|||
>>> components.choice_labeling = choice_labeling |
|||
>>> components.exit_rates = exit_rates |
|||
|
|||
And finally, we can build the model:: |
|||
|
|||
>>> ctmc = stormpy.storage.SparseCtmc(components) |
|||
>>> print(ctmc) |
|||
-------------------------------------------------------------- |
|||
Model type: CTMC (sparse) |
|||
States: 12 |
|||
Transitions: 22 |
|||
Reward Models: waiting, served |
|||
State Labels: 3 labels |
|||
* init -> 1 item(s) |
|||
* deadlock -> 0 item(s) |
|||
* target -> 2 item(s) |
|||
Choice Labels: 6 labels |
|||
* loop2a -> 2 item(s) |
|||
* serve1 -> 2 item(s) |
|||
* serve2 -> 2 item(s) |
|||
* loop2b -> 2 item(s) |
|||
* loop1b -> 2 item(s) |
|||
* loop1a -> 2 item(s) |
|||
-------------------------------------------------------------- |
|||
|
|||
|
@ -0,0 +1,34 @@ |
|||
************************************** |
|||
Markov automata (MAs) |
|||
************************************** |
|||
|
|||
|
|||
Background |
|||
===================== |
|||
|
|||
... works similar as explained in as in :doc:`building_dtmcs` |
|||
|
|||
.. seealso:: `01-building-mas.py <todo /examples/building_mas/01-building-mas.py>` |
|||
|
|||
First, we import Stormpy:: |
|||
|
|||
>>> import stormpy |
|||
|
|||
Transition Matrix |
|||
===================== |
|||
|
|||
|
|||
Labeling |
|||
================ |
|||
|
|||
|
|||
Reward models |
|||
================== |
|||
|
|||
|
|||
Exit Rates |
|||
==================== |
|||
|
|||
Building the Model |
|||
==================== |
|||
|
@ -0,0 +1,33 @@ |
|||
*********************************************** |
|||
Discrete-time Markov decision processes (MDPs) |
|||
*********************************************** |
|||
|
|||
|
|||
Background |
|||
===================== |
|||
|
|||
|
|||
.. seealso:: `01-building-mdps.py <todo /examples/mdps/01-building-mdps.py>` |
|||
|
|||
First, we import Stormpy:: |
|||
|
|||
>>> import stormpy |
|||
|
|||
Transition Matrix |
|||
===================== |
|||
|
|||
|
|||
Labeling |
|||
================ |
|||
|
|||
|
|||
Reward models |
|||
================== |
|||
|
|||
|
|||
Exit Rates |
|||
==================== |
|||
|
|||
Building the Model |
|||
==================== |
|||
|
Write
Preview
Loading…
Cancel
Save
Reference in new issue