visual-automata 0.0.1

Visual Automata is a Python 3 library built as a wrapper for Caleb Evans' Automata library to add more visualization features.

Visual Automata

Copyright 2021 Lewi Lie Uberg
Released under the MIT license

Visual Automata is a Python 3 library built as a wrapper for Caleb Evans' Automata library to add more visualization features.

Prerequisites

Automata
pip install automata-lib
pip install pandas
pip install graphviz
pip install colormath
pip install jupyterlab

Installing

pip install visual-automata

Contents

• Visual Automata
  • Prerequisites
  • Installing
  • VisualDFA
    • Importing
    • Instantiating DFAs
    • Converting
    • Minimal-DFA
    • Transition Table
    • Check input strings
    • Show Diagram
  • Authors
  • License
  • Acknowledgments

VisualDFA

Importing

Import needed classes.

from automata.fa.dfa import DFA

from visual_automata.fa.dfa import VisualDFA

Instantiating DFAs

Define an automata-lib DFA that can accept any string ending with 00 or 11.

dfa = VisualDFA(
    states={"q0", "q1", "q2", "q3", "q4"},
    input_symbols={"0", "1"},
    transitions={
        "q0": {"0": "q3", "1": "q1"},
        "q1": {"0": "q3", "1": "q2"},
        "q2": {"0": "q3", "1": "q2"},
        "q3": {"0": "q4", "1": "q1"},
        "q4": {"0": "q4", "1": "q1"},
    },
    initial_state="q0",
    final_states={"q2", "q4"},
)

Converting

An automata-lib DFA can be converted to a VisualDFA.

Define an automata-lib DFA that can accept any string ending with 00 or 11.

dfa = DFA(
    states={"q0", "q1", "q2", "q3", "q4"},
    input_symbols={"0", "1"},
    transitions={
        "q0": {"0": "q3", "1": "q1"},
        "q1": {"0": "q3", "1": "q2"},
        "q2": {"0": "q3", "1": "q2"},
        "q3": {"0": "q4", "1": "q1"},
        "q4": {"0": "q4", "1": "q1"},
    },
    initial_state="q0",
    final_states={"q2", "q4"},
)

Convert automata-lib DFA to VisualDFA.

dfa = VisualDFA(dfa)

Minimal-DFA

Creates a minimal DFA which accepts the same inputs as the old one. Unreachable states are removed and equivalent states are merged. States are renamed by default.

new_dfa = VisualDFA(
    states={'q0', 'q1', 'q2'},
    input_symbols={'0', '1'},
    transitions={
        'q0': {'0': 'q0', '1': 'q1'},
        'q1': {'0': 'q0', '1': 'q2'},
        'q2': {'0': 'q2', '1': 'q1'}
    },
    initial_state='q0',
    final_states={'q1'}
)

new_dfa.table

      0    1
→q0  q0  *q1
*q1  q0   q2
q2   q2  *q1

new_dfa.show_diagram()

minimal_dfa = VisualDFA.minify(new_dfa)
minimal_dfa.show_diagram()

minimal_dfa.table

                0        1
→{q0,q2}  {q0,q2}      *q1
*q1       {q0,q2}  {q0,q2}

Transition Table

Outputs the transition table for the given DFA.

dfa.table

       0    1
→q0   q3   q1
q1    q3  *q2
*q2   q3  *q2
q3   *q4   q1
*q4  *q4   q1

Check input strings

1001 does not end with 00 or 11, and is therefore Rejected

dfa.input_check("1001")

          [Rejected]                         
Step: Current state: Input symbol: New state:
1                →q0             1         q1
2                 q1             0         q3
3                 q3             0        *q4
4                *q4             1         q1

10011 does end with 11, and is therefore Accepted

dfa.input_check("10011")

          [Accepted]                         
Step: Current state: Input symbol: New state:
1                →q0             1         q1
2                 q1             0         q3
3                 q3             0        *q4
4                *q4             1         q1
5                 q1             1        *q2

Show Diagram

For IPython dfa.show_diagram() may be used.
For a python script dfa.show_diagram(view=True) may be used to automatically view the graph as a PDF file.

dfa.show_diagram()

The show_diagram method also accepts input strings, and will return a graph with gradient red arrows for Rejected results, and gradient green arrows for Accepted results. It will also display a table with transitions states stepwise. The steps in this table will correspond with the [number] over eached traversed arrow.

Please note that for visual purposes additional arrows are added if a transition is traversed more than once.

dfa.show_diagram("1001")

          [Rejected]                         
Step: Current state: Input symbol: New state:
1                →q0             1         q1
2                 q1             0         q3
3                 q3             0        *q4
4                *q4             1         q1

dfa.show_diagram("10011")

          [Accepted]                         
Step: Current state: Input symbol: New state:
1                →q0             1         q1
2                 q1             0         q3
3                 q3             0        *q4
4                *q4             1         q1
5                 q1             1        *q2

Authors

• Lewi Lie Uberg - uberg.me

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Acknowledgments

• Caleb Evans for his work on automata-lib.
• Geir Arne Hjelle, Michal Porteš, and Bart Willems for their general counsel.
• JFLAP for their work on a GUI based Automata application.