Math Graph

An implementation of graph on python

Description

This package provides the vertex, edge and graph structure in python. Also includes a drawer for graphs.

Usage

Import the package as

import mathgraph

Create some vertexes

v1=Vertex(name="Big node",weight=4)
v2=Vertex(name="Medium node",weight=3)
v3=Vertex(name="Medium node",weight=2)
v4=Vertex(name="Small node",weight=1)
v5=Vertex(name="Little node",weight=0.5)
v6=Vertex(name="Tiny node",weight=0.25)

Now some edges connecting the vertexes

e1=Edge(vstart=v1,vend=v2,cost=1)
e2=Edge(vstart=v1,vend=v3,cost=1.5)
e3=Edge(vstart=v2,vend=v4,cost=1)
e4=Edge(vstart=v3,vend=v5,cost=2)
e5=Edge(vstart=v5,vend=v6,cost=0)

And finally the graph. The graph accepts vertexes and edges, if you only put the edges it automatically add the vertexes to the graph:

g1=Graph(edges=[e1,e2,e3,e4,e5,e6])

You can see the graph with the command (don't work on Mac (yet)):

g1.draw()

Features

1. The structure is intented for a wide use, so the Vertex and Edge class include updaters. This updaters are a dictionary of stats that can change following some rules given by the updater function on the Graph class. The updaters on the graph is a dictionary with functions that takes some arguments and refresh the data of the updaters dictionary on Vertexes and Edges.

2. Some particular graphs were included, like Tree and NeuralNetFC. The Tree class, as it's name say, create a tree. You can also create a neural net. At this moments only accepts fully connected nn's.

3. The pack mathgraph.algorithms have some methods to apply over the structure Graph. Like Dijkstra and Greddy path search, and Kruskal minimum spanning tree. This paths can be visualized on the .draw() if you give it as arguments.

from algorithms.search_algorithms import Dijkstra
source=v1
target=v6
dj=Dijkstra(g1,source=source,target=target)
g1.draw(path=dj.get_path())

4. A graph can be created from an incidence matrix using a numpy matrix. Moreover, you can construct the incidence and adjacency matrix once you have a graph with the functions create_incidence_matrix(), create_adjacency_matrix(). The order of appearence of the vertex (rows) on the incidence matrix is given by the listing order of the vertex, same case for the columns and edges.

Requirements

pyglet, numpy.