def histogram():
"""
Draw plot that shows ratio of number of users and number of conferences that they visited.
"""
members, _ = get_members_and_conferences()
cnt = Counter([i.__len__() for i in members.values()])
del _
del members
gc.collect()
plt.plot(list(cnt.keys()), list(cnt.values()))
plt.xlabel('Number of conferences')
plt.ylabel(u'Number of users')
plt.axis([0, 60, 0, 50000])
def prepare_similarity_matrix():
"""
Compute similarity matrix for collaborative filtering model.
Weight is cosine between the vectors.
Weight will be computed only if two conferences include common users,
otherwise weight = 0.
"""
m = get_sparse_matrix()
members, conferences = get_members_and_conferences()
num_to_member, \
member_to_num, \
num_to_conference, \
conference_to_num, \
_, \
_ = get_mapping()
del _
len = m.shape[0]
m = m.tocsr()
print(len)
res = np.zeros((len,len))
squares = [0 for i in range(len)]
users = [[] for i in range(len)]
users_confs = [[] for i in range(m.shape[1])]
print('Preparing...')
cnt = 0
for i in range(len):
if (cnt * 100 / len) % 10 == 0:
print('{}%'.format(cnt * 100 / len))
cnt += 1
users[i] = list(map(lambda x: member_to_num[x], conferences[num_to_conference[i]]))
squares[i] = sqrt(users[i].__len__())
len2 = m.shape[1]
cnt = 0
for i in range(len2):
if cnt % 50000 == 0:
print('{}%'.format(cnt * 100 / len2))
cnt += 1
users_confs[i] = list(map(lambda x: conference_to_num[x],
members[num_to_member[i]]))
print('------\nMain part\n------')
cnt = 0
start = mktime(localtime())
matrix_file = open('output/similarity_triples.txt', 'a')
m = m.tocsc()
for i in range(len):
if cnt % 20 == 0:
print('---\n{}%'.format(round(cnt * 100 / len, 3)))
cnt += 1
for u in users[i]:
for uc in users_confs[u]:
if res[i, uc] == 0:
if users[uc].__len__() < users[i].__len__():
tmp = m[i, users[uc]].nonzero()[1].__len__()
else:
tmp = m[uc, users[i]].nonzero()[1].__len__()
tmp /= (squares[uc] * squares[i])
res[i, uc] = tmp
res[uc, i] = tmp
matrix_file.write('{},{},{}\n'.format(i, uc, tmp))
matrix_file.close()
end = mktime(localtime())
time = end - start
print('---------/n TIME = {} /n----------'.format(time))
