grafatko 0.2.1

An app for creating and visualizing graphs and graph-related algorithms.

Grafátko [gɾafɑtko]

An app for creating and visualizing graphs and graph-related algorithms.

Running Grafátko

First, install the app by running pip install grafatko. Then you can simply run the grafatko command from a terminal of your choice.

Controls

Mouse

• right button creates new nodes/vertices
• left button selects and drags nodes/vertices around the screen
• middle button pans the canvas
• mouse wheel zooms/rotates nodes about, depending on whether shift is pressed

Keyboard

• r toggles 'tree mode' for smoother visualisation of trees
  • essentially applies special forces on the nodes to group them by distance from the currently selected node
  • only works if a single mode is selected
• space centers on the currently selected nodes
• delete deletes the currently selected items

Visualizing algorithms

The app allows for visualising custom algorithms on the currently edited graph. Examples of valid programs can be found in the examples/ folder.

After creating a graph, you can go to Algorithms -> Run and select the one you want to run on the graph. The program then calls a function with the same name as the file, the only parameter being the DrawableGraph object to run the algorithm on.

Importing/exporting graphs

The app uses a simple format for importing and exporting graph. It consists of a list of vertices of the graph, with possible specifications to the direction and the weight of the given vertex.

A single line has the format n1 [direction] n2 [weight], where:

• n1 and n2 are labels of the nodes forming the vertex, containing no whitespace characters
• [direction] is used in directed graphs, and could be either -> or <-
• [weight] is used in weighted graphs, denotes the weight of the vertex

Examples of valid graphs can be found in the examples/ folder.