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doc ctmcs

refactoring
hannah 5 years ago
committed by Matthias Volk
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  1. 3
      doc/source/advanced_topics.rst
  2. 122
      doc/source/doc/building_ctmcs.rst
  3. 10
      doc/source/doc/building_dtmcs.rst
  4. 34
      doc/source/doc/building_mas.rst
  5. 33
      doc/source/doc/building_mdps.rst

3
doc/source/advanced_topics.rst

@ -11,6 +11,9 @@ This guide is a collection of examples meant to bridge the gap between the getti
doc/analysis
doc/building_models
doc/building_dtmcs
doc/building_ctmcs
doc/building_mas
doc/building_mdps
doc/engines
doc/exploration
doc/reward_models

122
doc/source/doc/building_ctmcs.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)
--------------------------------------------------------------

10
doc/source/doc/building_dtmcs.rst

@ -1,6 +1,6 @@
**********************************
************************************
Discrete-time Markov chains (DTMCs)
**********************************
************************************
Background
@ -11,7 +11,7 @@ Storm can be used to translate a model description e.g. in form of a prism file
Here, we use Stormpy to create the single components, to build a DTMC without parsing a model description.
We consider the previous example of the die.
.. seealso:: `01-building-dtmcs.py <todo/02-gspns.py/examples/building_dtmcs/01-building-dtmcs.py>`
.. seealso:: `01-building-dtmcs.py <todo /examples/building_dtmcs/01-building-dtmcs.py>`
In the following we create transition matrix, the state labeling and the reward models of a DTMC.
First, we import stormpy::
@ -52,7 +52,7 @@ All transitions are equipped with a probability defined by the value::
Lastly, we add a self-loop with probability one to the final states::
>>> for s in range(7,13):
>>> builder.add_next_value(s, s, 1)
... builder.add_next_value(s, s, 1)
Finally, we can build the matrix with updated row and columns count that both coincide with the number of states::
@ -73,7 +73,7 @@ In order to specify the state labeling we create an empty labeling for the given
>>> labels = {'init', 'one', 'two', 'three', 'four', 'five', 'six', 'done', 'deadlock'}
>>> for label in labels:
>>> state_labeling.add_label(label)
... state_labeling.add_label(label)
Next, we set teh associations between the labels and the respective states.::

34
doc/source/doc/building_mas.rst

@ -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
====================

33
doc/source/doc/building_mdps.rst

@ -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
====================
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