# -*- coding: utf-8 -*-

"""
PageRank
========

In this example we create a directed graph and compute PageRank. The graph
is the same as in the `wikipedia <https://en.wikipedia.org/wiki/PageRank>`_.

.. image :: https://upload.wikimedia.org/wikipedia/en/thumb/8/8b/PageRanks-Example.jpg/1024px-PageRanks-Example.jpg 

"""

# %%
# Start by importing the package

import jgrapht
import jgrapht.algorithms.scoring as scoring

# %%
# Creating a graph is done using the factory method. By default graphs are directed
# and weighted.

g = jgrapht.create_graph()

# %%
# We can add vertices by providing their identifier. The method returns `True` if the 
# vertex was added, `False` otherwise. Identifiers of vertices and edges are always
# integers.

for v in range(0, 11):
    g.add_vertex(v)

# %% 
# Our graph's vertex set now looks like

print (g.vertices)

# %%
# We also add the edges

g.add_edges_from([(1, 2), (2, 1), (3, 0), (3, 1), (4, 1), (4, 3), (4, 5), (5, 1), (5, 4),
   (6, 1), (6, 4), (7, 1),  (7, 4), (8, 1),  (8, 4), (9, 4), (10, 4)])

# %%
# We now have the following edges

print(g.edges)

# %%
# Execute Pagerank using
pagerank = scoring.pagerank(g)

# %%
# The returned object is a dictionary from vertices to floating point values.
# Let us store it in a list

result = [pagerank[v] for v in g.vertices]
print(result)