research, Inc. - HARPGraph2

HARPGraph2 (v0.1.0)

A generalized graph library for dealing with generalized graph structures. - Made by Harper Chisari

PseudoDiGraph

PseudoDiGraph is a class that supports both directed and undirected edges, as well as hyperedges. It uses an incidence matrix to represent the graph, where:

• 1 represents an undirected edge.
• 0.5 represents a directed edge away from a node.
• -0.5 represents a directed edge towards a node.

Features

1. Adding Nodes and Edges

   • add_node(node): Adds a node to the graph.
   • add_edge(nodes): Adds an edge to the graph. If nodes is a tuple, it is treated as a directed edge; if it is a list, it is treated as an undirected edge.

2. Removing Nodes and Edges

   • remove_node(node): Removes a node and all edges connected to it from the graph.
   • remove_edge(nodes): Removes a specified edge from the graph.

3. Getting Edges

   • get_undirected_edges(nodes=None): Returns all undirected edges. If nodes is specified, only edges involving those nodes are returned.
   • get_directed_edges(nodes=None): Returns all directed edges. If nodes is specified, only edges involving those nodes are returned.

4. Plotting and Exporting

   • plot(): Plots the graph and stores the coordinates for future exports.
   • export(output_folder='output_images', filename='graph_plot.png'): Exports the graph plot to a specified file using the coordinates generated by plot().

Examples

Creating a Directed Graph

from HARPGraph2 import PseudoDiGraph

# Create a directed graph
graph = PseudoDiGraph(directed=True)
graph.add_edge(('A', 'B'))  # Directed edge from A to B
print("Directed edges:", graph.get_directed_edges())
graph.plot()  # Displays the plot
graph.export()  # Saves the plot to the default 'output_images/graph_plot.png'

Creating an Undirected Graph

from HARPGraph2 import PseudoDiGraph

# Create an undirected graph
graph = PseudoDiGraph()
graph.add_node('C')
graph.add_node('D')
graph.add_edge(('C', 'D'))  # Unordered hyper edge between C and D
graph.add_node('E')
graph.add_node('F')
graph.add_edge(('D', 'E'))  # Directed edge from D to E
graph.add_edge(('E', 'C'))  # Directed edge from E to D
graph.add_edge(['C', 'F'])  # Undirected edge between C and F
print("Undirected edges:", graph.get_undirected_edges())
print("Directed edges:", graph.get_directed_edges())
graph.plot()  # Displays the plot
graph.export(output_folder="output_images")  # Saves the plot to the default 'output_images/graph_plot.png'

Removing Nodes and Edges

from HARPGraph2 import PseudoDiGraph

# Create a graph and add nodes and edges
graph = PseudoDiGraph()
graph.add_node('C')
graph.add_node('D')
graph.add_edge(('C', 'D'))  # Unordered hyper edge between C and D
graph.add_node('E')
graph.add_node('F')
graph.add_edge(('D', 'E'))  # Directed edge from D to E
graph.add_edge(('E', 'C'))  # Directed edge from E to D
graph.add_edge(['C', 'F'])  # Undirected edge between C and F

# Remove edges and nodes
graph.remove_edge(('C', 'D'))
graph.remove_node('E')
print("Undirected edges after removal:", graph.get_undirected_edges())
print("Directed edges after removal:", graph.get_directed_edges())
graph.plot()  # Displays the plot after removals
graph.export(output_folder="output_images", filename="graph_plot_after_removal.png")  # Saves the plot to 'output_images/graph_plot_after_removal.png'

Installation

To install the library, clone the repository and run:

pip install HARPGraph2

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