CHANGELOG.md

Changelog

10th November 2023: Fire!

• untimed_pn:
  • method fire() of class PetriNet to fire a transition of a Petri net and see how the state evolves
  • method closedLoop() returns the Petri net representing the closed-loop system "plant + controller", where the plant is represented by a Petri net and the controller is a state-based controller computed using method getStateController()

13th March 2023: Bug fix, critical graph, and formatting

• max_plus:
  • method cyclicity() now returns the right cyclicity of a irreducible Matrix, using the circuits of the critical graph
  • method critical() of class PrecedenceGrapg added, which allows to determine the critical graph associated to a givven precedence graph
  • method __format__() of class Matrix added, which allows to choose among different formats for printing the matrix

15th January 2023: Colorful Gantt charts

• max_plus:
  • Gantt charts are now colored, and multi occupancy is shown by stacking bars vertically
  • method __eq__() returns false when comparing Matrix object with something else
  • method __str__() now visualizes epsilons and e's as such (instead of -inf and 0); moreover, matrices are nicely displayed (following pseudo-Matlab style)
  • method eigenvectors() now returns a matrix, whose columns are eigenvectors (transposed w.r.t. before)
  • precedence graphs now are more informative: gray nodes correspond to those that do not belong to any msc subgraph
  • distinction between strongly connected and maximal strongly connected components no more useful. Method strongly_connected_components() to be removed in future versions
  • trajectories now visualize epsilons and e's as such. Moreover, horizontal distance is decreased and should be more consistent

10th November 2022: Added new features and cleaned the directory

• Renamed toolbox to petritub, and toolbox modules to untimed_pn, max_plus, and min_plus
• max_plus:
  • Class Matrix:
    • more flexible handling of scalar objects
    • methods __radd__(), __rmul__() for reverse operations added
    • methods del_row() and del_col() to delete single rows and columns
    • methods zero(), top() renamed into zeros() and tops(), respectively
    • method ones() (similar to zeros() but for e-elements) added
    • method __pow__() for exponentiation added
    • method T() fixed, now the retuned Matrix has the right width and height
  • function mp() to construct a Matrix object
  • function concatenate() to construct block matrices
  • functions zeros(), eye(), ones(), top() independent from class Matrix
  • function trajectory() now can compute the trajectory for non-autonomous systems
  • function output_trajectory() to compute the output trajectory for a non-autonomous system
• notebook tutorial_max_plus now extended, to show other functionalities
• now the documentation updates automatically once the files are modified. Also, extensions nbsphinx and nbsphinx_link added to sphinx for more flexibility

12th August 2022: Submitted version

• General improvements to code readability and comments
• Documentation of all ("non-private") classes and methods
• Renamed the class "Schedule" to "Gantt"
• Min-plus toolbox added: dual toolbox to the max-plus toolbox with classes Matrix and PrecedenceGraph

3rd July 2022: Gantt charts

• Methods eigenvalue() and eigenvectors() moved to the Matrix class
• Method trajectory(): computes trajectory for x(k+1)=Ax(k), x(0)=x_0, input arguments are A, x(0) and k_end (number of iterations)
• Class Matrix:
  • method cyclicity(), same as cyc() computes the cyclicity of an irreducible matrix
  • method is_irreducible()
• Class PrecedenceGraph:
  • method critical_circuits() returns a list of critical (elementary) circuits
  • added parameters for spread and seed in draw() method
  • methods savefig(), savefig_critical() to save the graph as a pdf
  • method is_strongly_connected()
• Class Schedule (new) later renamed to Gantt: for drawing resource occupation as a bar chart (Gantt chart)
  • inpus arguments: Matrix or 2d array (each column is x(k) for a specific k value) and pairs of transitions
  • method draw(t_end=40) draws the bar chart, up to a specified end time
  • method save() saves the chart as a pdf

13th June 2022: Critical graph

• Function eigenvalue(A) computes the largest eigenvalue of A
• Function eigenvectors(A) lists the linearly (in)dependent eigenvectors of A
• Class PrecedenceGraph: class for precedence graph corresponding to a max-plus matrix
  • draw: draws the precedence graph, where each strongly connected component has a unique color
  • draw_critical: draws the critical graph, where non-critical components are drawn transparently
  • strongly_connected_components: lists the strongly connected components
  • transpose: returns the transpose graph (directions of all arrows are reversed)
  • cycles: returns a list of (elementary) cycles of the graph
  • subgraph(nodes): returns a subgraph consisting of the given node list and the corresponding edges
  • msc_components: lists the maximally strongly connected components of the critical graph
  • critical_cycles: returns a list of critical cycles of the graph
  • critical_edges: returns a list of critical edges of the graph

7th May 2022: First commit

• First version of the max-plus toolbox, including matrix operations and a class for max-plus matrices
  • zero, top and identity matrices
  • star and plus operator