# -*- coding: utf-8 -*-
"""
Created on Mon Nov 20 13:02:11 2017

@author: nano
Thesis = Nano Y.P. 2017

Implementasi untuk Uji data graf homogen utk coauthur network (DBLP)
Tujuan : tujuannya untuk melihat bagaimana kelompok author yang terbentuk
         berdasarkan kerjasama author 
         pada masing-masing paper computer science

Method : spectral clustering []
http://scikit-learn.org/stable/modules/clustering.html#spectral-clustering 
"""
import numpy as np
import networkx as nx
from sklearn.cluster import SpectralClustering
from sklearn import metrics
np.random.seed(1)

# Get your mentioned graph
G = nx.karate_club_graph()

# Get ground-truth: club-labels -> transform to 0/1 np-array
#     (possible overcomplicated networkx usage here)
gt_dict = nx.get_node_attributes(G, 'club')
gt = [gt_dict[i] for i in G.nodes()]
gt = np.array([0 if i == 'Mr. Hi' else 1 for i in gt])

# Get adjacency-matrix as numpy-array
adj_mat = nx.to_numpy_matrix(G)

print('ground truth')
print(gt)

# Cluster
sc = SpectralClustering(2, affinity='precomputed', n_init=100)
sc.fit(adj_mat)

# Compare ground-truth and clustering-results
print('spectral clustering')
print(sc.labels_)
print('just for better-visualization: invert clusters (permutation)')
print(np.abs(sc.labels_ - 1))

# Calculate some clustering metrics
print(metrics.adjusted_rand_score(gt, sc.labels_))
print(metrics.adjusted_mutual_info_score(gt, sc.labels_))