pykp.knapsack.Knapsack.

plot_graph

Knapsack.plot_graph(ax: Axes = None, colour_map: dict = None, show_legend: bool = True) → tuple[Figure, Axes]

Visualises a graph representation of the knapsack problem.

Each node in the graph represents a unqiue arrangement of items inside the knapsack. Edges connect nodes whose states differ by a single item, and represent the elementary operations of adding or removing a single item from the knapsack.

Parameters:

axmatplotlib.pyplot.Axes, optional

An existing axes object to plot on. Defaults to None.

Returns:

tuple of (matplotlib.pyplot.Figure, matplotlib.pyplot.Axes)

The figure and axes of the created or updated plot.

Other Parameters:

colour_mapdict, optional

A dictionary mapping node types to colours. A valid colour map must contain keys “optimal”, “feasible”, and “infeasible”. Default is None.

show_legendbool, optional

Whether to display a legend on the plot. Default is True.

Examples

>>> from pykp.knapsack import Sampler
>>> import matplotlib.pyplot as plt
>>>
>>> sampler = Sampler(num_items=6, normalised_capacity=0.6)
>>> sample = sampler.sample(seed=42)
>>> fig, ax = sample.plot_graph()
>>> plt.show()