def __buildNMF(self, num_topics, chunksize, passes):
self.__model = Nmf(self.__corpus,
id2word=self.__corpus.getDictionary(),
num_topics=num_topics,
chunksize=chunksize,
passes=passes,
eval_every=None,
random_state=10)
def topic_modeling(method, num_topics, corpus, dictionary):
if method == 'LDA':
# Build LDA model
model = gensim.models.ldamodel.LdaModel(corpus=corpus,
id2word=dictionary,
num_topics=num_topics,
random_state=42,
update_every=1,
chunksize=10,
passes=10,
alpha='symmetric',
iterations=100,
per_word_topics=True)
elif method == 'NMF':
#Build NMF model
model = Nmf(corpus=corpus,
num_topics=num_topics,
id2word=dictionary,
chunksize=10,
passes=10,
kappa=0.5,
w_max_iter=200,
h_max_iter=50,
eval_every=1,
normalize=True,
random_state=42)
else:
raise ValueError('method is invalid')
return model
def load(self, model_name):
self.__modelName = model_name
if model_name == 'lda':
self.__model = LdaMulticore.load(self.__modelFile)
elif model_name == 'nmf':
self.__model = Nmf.load(self.__modelFile)
def create_nmf_model(id_dict, corpus, num_topics):
nmf_model = Nmf(corpus=corpus,
id2word=id_dict,
num_topics=num_topics,
random_state=100,
chunksize=100,
passes=50)
return nmf_model
def __buildLDA(self, num_topics, chunksize, passes):
self.__model = LdaMulticore(self.__corpus,
id2word=self.__corpus.getDictionary(),
num_topics=num_topics,
chunksize=chunksize,
passes=passes,
eval_every=None,
workers=40,
random_state=10)
def find_cv(): #Find Number of K
for num in topic_nums:
nmf = Nmf(corpus=corpus,
num_topics=num,
id2word=dictionary,
normalize=True)
cm = CoherenceModel(model=nmf,
texts=texts,
dictionary=dictionary,
coherence='c_v')
coherence_scores.append(round(cm.get_coherence(), 5))
def __create_model(self, algo, topic_qtt):
model = None
if (algo == TopicModelingAlgorithm.LDA):
model = LdaModel(corpus=self.__corpus,
num_topics=topic_qtt,
id2word=self.__id2_words,
random_state=1)
elif (algo == TopicModelingAlgorithm.LSA):
model = LsiModel(corpus=self.__corpus,
num_topics=topic_qtt,
id2word=self.__id2_words)
elif (algo == TopicModelingAlgorithm.NMF):
model = Nmf(corpus=self.__corpus,
num_topics=topic_qtt,
random_state=1)
return model
def nmf_search(texts, query, num_topics, passes=20, random_state=None):
tfidf_model, dic, text_tfidf_weights = get_tfidfmodel_and_weights(texts)
# NMFモデルを作成
nmf_model = Nmf(corpus=text_tfidf_weights,
id2word=dic,
num_topics=num_topics,
passes=passes,
random_state=random_state)
# TF・IDFによる文書ベクトルをトピックベースのベクトルに変換
nmf_weights = nmf_model[text_tfidf_weights]
index = MatrixSimilarity(nmf_weights, num_features=len(dic))
# クエリのトピックベースのベクトルを作成
query_bows = get_bows([query], dic)
query_tfidf_weights = get_weights(query_bows, dic, tfidf_model)
query_nmf_weights = nmf_model[query_tfidf_weights]
# クエリとの類似性で文書をランキング
sims = index[query_nmf_weights[0]]
return sorted(enumerate(sims), key=lambda x: x[1], reverse=True)
def nmf(filename):
# tf-idf
min_df = 10
max_df = 0.60
max_features = 5000
# sklearn-model nmf
# get data
newspaper_input = pd.read_csv(filename, na_filter=False)
newspaper_input['processed_text'] = newspaper_input['article'].apply(
process_text)
texts = newspaper_input['processed_text']
# create dictionary to pass as input to gensim model
dictionary = Dictionary(newspaper_input['processed_text'])
# filter out words that are above or below the thresholds set
dictionary.filter_extremes(no_below=10, no_above=0.60, keep_n=5000)
# convert to bag of words (corpus) to pass to gensim nmf model
# [[(word_id, # times word appears in document),...],...]
corpus = [dictionary.doc2bow(text) for text in texts]
# find optimal number of topics using gensim NMF https://radimrehurek.com/gensim/models/nmf.html
# testing topic numbers 10,15,20...55 to find best number to fit the data
topic_nums = list(np.arange(10, 56, 5))
coherence_scores = []
for num in topic_nums:
# initialize NMF model
nmf = Nmf(
corpus=corpus,
num_topics=num,
id2word=dictionary,
chunksize=
500, #Number of documents to be used in each training chunk
passes=10, #Number of full passes over the training corpus
kappa=0.1, #Gradient descent step size
minimum_probability=0.001,
w_max_iter=
300, # Maximum number of iterations to train W per each batch
w_stop_condition=
0.0001, # If error difference gets less than that, training of W stops for the current batch
h_max_iter=100,
h_stop_condition=0.001,
normalize=True,
random_state=42)
# initialize Coherence Model https://radimrehurek.com/gensim/models/coherencemodel.html
# Calculate topic coherence for topic models
cm = CoherenceModel(model=nmf,
texts=texts,
dictionary=dictionary,
coherence='c_v')
coherence_scores.append(round(cm.get_coherence(), 5))
# get list of different topic numbers and their respective scores
scores = list(zip(topic_nums, coherence_scores))
# sort scores by score (not topic_num)
scores = sorted(scores, key=itemgetter(1), reverse=True)
# get the best number of topics
best_num_topics, best_coherence_score = scores[0]
# best_coherence_score = scores[0][1]
print('scores: ', scores)
print('num_topics: ', str(best_num_topics))
print('coherence: ', str(best_coherence_score))
# print(df.head())
tfidf_vectorizer = TfidfVectorizer(
ngram_range=(1, 2), # unigrams and bigrams
max_df=0.60,
min_df=10,
max_features=5000,
preprocessor=' '.join)
# fit+transform: returns document-term matrix (frequency of word i in document j)
tfidf = tfidf_vectorizer.fit_transform(texts)
# all the words we'll be looking at
tfidf_fn = tfidf_vectorizer.get_feature_names()
# grid search for best alpha, l1_ratio combination
# measured by lowest sum squared residual
# l1_ratio: regularization mixing parameter (0 => l2 penalty, 1 => l1 penalty, (0,1) => mixture)
# alpha: constant that multiplies the regularization terms (0 => no regularization)
squared_residuals = []
params = {}
models = []
sorted_articles_dfs = []
complete_topics_dfs = []
alphas = list(np.arange(0.0, 1.2, 0.2))
l1_ratios = list(np.arange(0.0, 1.2, 0.2))
count_params = 0
successes = 0
count_successes = {}
for a in alphas:
for b in l1_ratios:
# print('alpha: {}, l1_ratio: {}'.format(a,b))
# learn a model
nmf = NMF(
n_components=best_num_topics,
init=
'nndsvd', # Non-negative double singular value decomposition
max_iter=500,
l1_ratio=b,
solver='cd', # coordinate descent
alpha=a,
tol=0.0001, # 0.001
random_state=42).fit(tfidf)
try:
# transforms documents -> document-term matrix, transforms data according to model
docweights = nmf.transform(tfidf) # (articles x topics)
# topic dataframe: (best_num_topics x 8)
# (topic num : top 8 words that describe the topic)
n_top_words = 8
topic_df = topic_table(nmf, tfidf_fn, n_top_words).T
# clean the topic words
topic_df['topics'] = topic_df.apply(lambda x: [' '.join(x)],
axis=1)
topic_df['topics'] = topic_df['topics'].str[0]
topic_df['topics'] = topic_df['topics'].apply(
lambda x: whitespace_tokenizer(x))
topic_df['topics'] = topic_df['topics'].apply(
lambda x: unique_words(x))
topic_df['topics'] = topic_df['topics'].apply(
lambda x: [' '.join(x)])
topic_df['topics'] = topic_df['topics'].str[0]
# clean topic dataframe
topic_df = topic_df['topics'].reset_index()
topic_df.columns = ['topic_num', 'topics']
topics = topic_df[['topic_num', 'topics']]
# assign topics to each article
title = newspaper_input['title'].tolist()
df_temp = pd.DataFrame({
'title': title,
'topic_num': docweights.argmax(axis=1)
})
merged_topic = df_temp.merge(topic_df,
on='topic_num',
how='left')
complete_df = merged_topic.merge(newspaper_input,
on='title',
how='left')
# complete_df = complete_df.drop('processed_text', axis=1)
# maybe unecessary ?
complete_df = complete_df.drop_duplicates(subset=['title'])
sorted_articles = complete_df.sort_values(by=['topic_num'])
# get num articles per topic
num_articles_per_topic = []
for topic in range(best_num_topics):
count = 0
for index, row in sorted_articles.iterrows():
if row['topic_num'] == topic:
count += 1
num_articles_per_topic.append(count)
# keep track of how many articles are given each topic
topics['num_articles'] = num_articles_per_topic
# matrices from nmf (A = WH)
mat_A = tfidf_vectorizer.transform(texts)
mat_W = nmf.components_
mat_H = nmf.transform(mat_A)
# residuals: measurement of how well the topics approximate the data (observed value - predicted value)
# 0 -> topic perfectly predicts data
# residual = Frobenius norm tf-idf weights (A) - coefficients of topics (H) X coefficients of topics (W)
r = np.zeros(mat_A.shape[0]) # num articles
for row in range(mat_A.shape[0]):
r[row] = np.linalg.norm(
mat_A[row, :] - mat_H[row, :].dot(mat_W), 'fro')
sum_sqrt_res = round(sum(np.sqrt(r)), 3)
squared_residuals.append(sum_sqrt_res)
# add avg residual column to topics
complete_df['resid'] = r
sorted_articles = complete_df.sort_values(by=['topic_num'])
resid_data = complete_df[[
'topic_num', 'resid'
]].groupby('topic_num').mean().sort_values(by='resid')
complete_topics = topics.merge(resid_data,
on='topic_num',
how='left')
# save results
sorted_articles_dfs.append(sorted_articles)
complete_topics_dfs.append(complete_topics)
models.append(nmf)
count_successes[count_params] = successes
successes += 1
except Exception as e:
# print('test {}, error occurred'.format(count_params))
exc_type, exc_obj, exc_tb = sys.exc_info()
fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
print(exc_type, fname, exc_tb.tb_lineno)
# print('test {} complete'.format(count_params))
params[count_params] = (a, b)
count_params += 1
# find best params
params_test = np.arange(36)
resid_scores = list(zip(params_test, squared_residuals))
resid_scores = sorted(resid_scores, key=itemgetter(1))
best_params = resid_scores[0][0]
print('test #{} had best residual score'.format(best_params))
print('params: a={}, b={}'.format(params[best_params][0],
params[best_params][1]))
print('residual scores: {}'.format(resid_scores))
best_articles = sorted_articles_dfs[count_successes[best_params]]
best_topics = complete_topics_dfs[count_successes[best_params]]
# call function that uses svc model to predict category based on topic words
best_topics = predict_category(best_topics)
# save best topics
for idx, row in best_topics.iterrows():
new_words = ''
topics_itr = row['topics'].split()
for word in topics_itr:
new_words += get_unstemmed_word(word)
new_words += ' '
best_topics.at[idx, 'topics'] = new_words
categories = []
for idx, row in best_articles.iterrows():
topic_num = row['topic_num']
topics = best_topics.at[topic_num, 'topics']
categories.append(best_topics.at[topic_num, 'predicted_category'])
best_articles.at[idx, 'topics'] = topics
best_articles['predicted_category'] = categories
best_articles = best_articles.drop('processed_text', axis=1)
best_articles = best_articles.drop('Unnamed: 0', axis=1)
best_articles.to_csv('../output/topic/articles_with_nmf_topics.csv',
header=True,
index=False)
best_topics.to_csv('../output/topic/nmf_generated_topics.csv',
header=True,
index=False)
# save model
with open('nmf_model.pickle', 'wb') as output:
pickle.dump(models[best_params], output)
with open('nmf_tfidf.pickle', 'wb') as output:
pickle.dump(tfidf_vectorizer, output)
# import argparse
from gensim.corpora import Dictionary, MmCorpus
from gensim.models.nmf import Nmf
from gensim.models import TfidfModel
from codebase.utils import TweetRawCorpusStream
from codebase.topic_utilities import export_dtm
if __name__ == "__main__":
corpora_path = "./corpora/"
model_path = "./models/"
num_topics = 50
model_suffix = "-{}topics".format(num_topics)
modelTag = "Seventh-and-EighthWeek-Tweets-Rolling"
nmf = Nmf.load("{}{}{}.model".format(model_path, modelTag, model_suffix))
fileTag_list = ["First-and-SecondWeek-Tweets-Rolling"]
for fileTag in fileTag_list:
tfidf_corpus = MmCorpus('{}{}-tf-idf.mm'.format(corpora_path, fileTag))
export_dtm(nmf=nmf, corpus=tfidf_corpus,\
out_path="{}{}{}-dtm.csv".format(model_path, fileTag, model_suffix),\
stop_at=None)
common_dictionary = Dictionary(docs)
common_corpus = [common_dictionary.doc2bow(text) for text in docs]
# for k in range(4, 10):
# nmf = Nmf(common_corpus, num_topics=k)
# c_model = CoherenceModel(model=nmf, corpus=common_corpus, dictionary=common_dictionary, texts=docs, coherence='c_v')
# print(k, c_model.get_coherence())
# x = PrettyTable()
# x.field_names = [''] + [ "t" + str(i+1) for i in range(0,10)]
# for i in range(0,k):
# x.add_row([i] + [ common_dictionary[term] for (term, w) in nmf.get_topic_terms(i)])
# print(x)
from gensim.matutils import jaccard
import random
nmf = Nmf(common_corpus, num_topics=9)
texts = random.choices(docs, k=20)
texts = [docs[0], docs[20], docs[80], docs[90], docs[200], docs[210]] #[docs[i] for i in range(0, len(docs), 30)]
def get_most_likely_topic(doc):
bow = common_dictionary.doc2bow(doc)
topics, probabilities = zip(*nmf.get_document_topics(bow))
max_p = max(probabilities)
topic = topics[probabilities.index(max_p)]
return topic
colors = ["skyblue", "pink", "red", "green", "yellow", "cyan", "purple", "magenta", "orange", "blue"]
def get_node_color(i):
return colors[get_most_likely_topic(texts[i])]
# return 'skyblue' if get_most_likely_topic(texts[i]) == 0 else 'pink'
def compute_coherence_values(self,
limit,
start=2,
step=3,
model_type="lda",
corpus_type="bow",
show_details=False):
"""
Compute c_v coherence for various number of topics
Parameters:
----------
dictionary : Gensim dictionary
corpus : Gensim corpus
texts : List of input texts
limit : Max num of topics
model_type : lda or mallet or nmf
Returns:
-------
model_list : List of LDA topic models
coherence_values : Coherence values corresponding to the LDA model with respective number of topics
"""
self.get_term_doc_frequency()
coherence_values = []
model_list = []
topics_num_arr = []
os.environ[
'MALLET_HOME'] = 'C:\\Mallet\\' # for windows make sure you put the mallet folder under C and unzip it
mallet_path = 'C:\\Mallet\\bin\\mallet'
corpus_to_train = self.corpus
if corpus_type == 'tfidf':
print("training on TFIDF")
tfidf = models.TfidfModel(self.corpus)
corpus_to_train = tfidf[self.corpus]
else:
print("training on BOW")
#mallet_path = 'C:...mallet_unzipped\\mallet-2.0.8\\bin\\mallet'
for num_topics in range(start, limit, step):
if model_type == "lda":
model = gensim.models.ldamodel.LdaModel(corpus=corpus_to_train,
id2word=self.id2word,
num_topics=num_topics,
random_state=1,
update_every=1,
chunksize=10,
passes=10,
alpha='auto',
per_word_topics=True)
elif model_type == "mallet":
model = gensim.models.wrappers.LdaMallet(
mallet_path,
corpus=corpus_to_train,
num_topics=num_topics,
id2word=self.id2word,
random_seed=1)
elif model_type == "nmf":
model = Nmf(corpus=corpus_to_train,
num_topics=num_topics,
id2word=self.id2word,
random_state=1)
else:
print(
'model {} is not supported. the models are *lda*, *mallet* and *nmf*'
)
model_list.append(model)
topics_num_arr.append(num_topics)
coherence_model = CoherenceModel(model=model,
texts=self.data_lemmatized,
dictionary=self.id2word,
coherence='c_v')
coherence_num = coherence_model.get_coherence()
coherence_values.append(coherence_num)
print(num_topics, ': - coherence:', coherence_num)
optimal_idx = np.argmax(coherence_values)
self.model = model_list[optimal_idx]
self.num_topics = topics_num_arr[optimal_idx]
print("optimal model has a coherence value of ",
round(coherence_values[optimal_idx], 2), ' and # topics: ',
(topics_num_arr[optimal_idx]))
# Visualize
topic_modeler.show_coherence_vals_graph(coherence_values,
limit,
start=start,
step=step)
if show_details:
for m, cv in zip(topics_num_arr, coherence_values):
print("Num Topics =", m, " has Coherence Value of",
round(cv, 4))
return model_list, coherence_values
def main(query,output_filename,window=50,topicn=50):
print ('Training nmf model began')
frame = inspect.currentframe()
args, _, _, values = inspect.getargvalues(frame)
query_parameters = [(i, values[i]) for i in args]
document_collection_original=blacklab.search_blacklab(query,window=window,lemma=True, include_match=False)
print ("Search finished")
document_collection=[match['complete_match'].strip() for match in document_collection_original[0:100]]
#Use the phraser model
phraser_model = Phraser(Phrases.load(constants.OUTPUT_FOLDER+'phrase_model'))
document_collection=[' '.join(phraser_model[match['complete_match'].strip().split()]) for match in document_collection_original]
print ("Phraser model done")
#get rid of stop words
document_collection_filtered = document_collection
'''
for text in document_collection:
new_text = []
for word in text.split():
if (word not in set(stopwords.words('english')) and (word[0] in string.ascii_uppercase + string.ascii_lowercase)):
new_text.append(word)
document_collection_filtered.append(' '.join(new_text))
'''
print ("Filtering done")
#build the corpus
preprocessed_corpus = []
for i,text in enumerate(document_collection_filtered):
if i==0:
print (i)
text = text.split()
dct=gensim_utils.initialize_gensim_dictionary([text])
else:
print (i)
text = text.split()
gensim_utils.add_documents_to_gensim_dictionary(dct,[text])
#Filter it here
dct.filter_extremes(no_below=10, no_above=0.95)
gensim_corpus = [dct.doc2bow(bag_of_word.split()) for bag_of_word in document_collection_filtered]
#text = document_collection_filtered[0].split()
nmf = Nmf(gensim_corpus, num_topics=50)
words = list(dct.token2id.keys())
topics = nmf.print_topics(50)
for topic in topics:
topic_words = topic[1].split('+')
print_topic = []
for topic_word in topic_words:
print_topic.append(words[int(topic_word.split('*')[1][1:].strip()[:-1])])
print (' '.join(print_topic))
#get topic of a given document: nmf.get_document_topics(gensim_corpus[0])
#dct.token2id.keys()
#nmf.show_topic(10)
#nmf.get_document_topics(dct.doc2bow(preprocessed_corpus[0]))
pdb.set_trace()
class TopicModel(object):
def __init__(self):
self.__corpus = None
self.__modelName = None
self.__model = None
self.__modelFile = 'results/model.bin'
self.__coherenceModel = None
def setCorpus(self, corpus):
self.__corpus = corpus
def getCoherence(self):
return self.__coherenceModel.get_coherence()
def getDocumentTopics(self, document, threshold=None):
return self.__model.get_document_topics(document, threshold)
def build(self, model_name, num_topics, chunksize, passes, corpus=None):
self.__modelName = model_name
# Update corpus if necessary
if isinstance(corpus, Corpus):
self.__corpus = corpus
# Build topic model
if model_name == 'lda':
self.__buildLDA(num_topics, chunksize, passes)
elif model_name == 'nmf':
self.__buildNMF(num_topics, chunksize, passes)
# Build coherence model
self.__buildCoherenceModel()
def __buildLDA(self, num_topics, chunksize, passes):
self.__model = LdaMulticore(self.__corpus,
id2word=self.__corpus.getDictionary(),
num_topics=num_topics,
chunksize=chunksize,
passes=passes,
eval_every=None,
workers=40,
random_state=10)
def __buildNMF(self, num_topics, chunksize, passes):
self.__model = Nmf(self.__corpus,
id2word=self.__corpus.getDictionary(),
num_topics=num_topics,
chunksize=chunksize,
passes=passes,
eval_every=None,
random_state=10)
def __buildCoherenceModel(self):
self.__coherenceModel = CoherenceModel(model=self.__model,
texts=self.__corpus.getTexts(),
coherence='c_v',
processes=7)
def __printTopics(self):
print(' Topics')
for idx, topic in self.__model.print_topics(-1):
print(' {}: {}'.format(idx, topic))
def save(self):
self.__model.save(self.__modelFile)
def load(self, model_name):
self.__modelName = model_name
if model_name == 'lda':
self.__model = LdaMulticore.load(self.__modelFile)
elif model_name == 'nmf':
self.__model = Nmf.load(self.__modelFile)
dest="preFileTag",
help='preFileTag used to select previous nmf model')
args = parser.parse_args()
num_topics = args.num_topics
fileTag = args.fileTag
preFileTag = args.preFileTag
preDictTag = args.preDictTag
corpora_path = "./corpora/"
model_path = "./models/"
model_suffix = "-{}topics".format(num_topics)
#### Step 1, Load Corpus ####
if (preFileTag == None) and (preDictTag == None):
dct = Dictionary.load('{}{}.dict'.format(corpora_path, fileTag))
# for rolling way first built model
elif (preFileTag == None) and (preDictTag != None):
dct = Dictionary.load('{}{}.dict'.format(corpora_path, preDictTag))
tfidf_corpus = MmCorpus('{}{}-tf-idf.mm'.format(corpora_path, fileTag))
#### Step 2, train NMF to extract topic patterns ####
if preFileTag == None:
nmf = Nmf(tfidf_corpus, id2word=dct, num_topics=num_topics)
elif preFileTag != None:
nmf = Nmf.load("{}{}{}.model".format(model_path, preFileTag,
model_suffix))
nmf.update(tfidf_corpus)
#### Step 3, export model ####
nmf.save("{}{}{}.model".format(model_path, fileTag, model_suffix))
def train(self,
data=AbstractModel.ROOT + '/data/test.txt',
num_topics=20,
preprocessing=False,
passes=1,
kappa=1.0,
minimum_probability=0.01,
w_max_iter=200,
w_stop_condition=0.0001,
h_max_iter=50,
h_stop_condition=0.001,
eval_every=10,
normalize=True,
random_state=None):
"""
Train the model and generate the results on the corpus
:param data: The training corpus as path or list of strings
:param int num_topics: The desired number of topics
:param bool preprocessing: If true, apply preprocessing to the corpus
:param int passes: Number of full passes over the training corpus. Leave at default passes=1 if your input is an iterator.
:param float kappa: Gradient descent step size. Larger value makes the model train faster, but could lead to non-convergence if set too large.
:param float minimum_probability: If normalize is True, topics with smaller probabilities are filtered out. If normalize is False, topics with smaller factors are filtered out. If set to None, a value of 1e-8 is used to prevent 0s.
:param float w_max_iter: Maximum number of iterations to train W per each batch.
:param float w_stop_condition: If error difference gets less than that, training of W stops for the current batch.
:param float h_max_iter: Maximum number of iterations to train h per each batch.
:param float h_stop_condition: If error difference gets less than that, training of h stops for the current batch.
:param int eval_every: Number of batches after which l2 norm of (v - Wh) is computed. Decreases performance if set too low.
:param bool normalize: Whether to normalize the result. Allows for estimation of perplexity, coherence, e.t.c.
:param int random_state: Seed for random generator. Needed for reproducibility.
"""
frequency = defaultdict(int)
data = input_to_list_string(data, preprocessing)
for text in data:
for token in text.split(' '):
frequency[token] += 1
if preprocessing:
data = map(preprocess, data)
texts = [[
token for token in text.split(' ')
if frequency[token] > 1 and len(token) > 0
] for text in data]
dictionary = Dictionary(texts)
corpus = [dictionary.doc2bow(text) for text in texts]
nmf_model = Nmf(corpus,
id2word=dictionary,
num_topics=num_topics,
kappa=kappa,
minimum_probability=minimum_probability,
w_max_iter=w_max_iter,
w_stop_condition=w_stop_condition,
h_max_iter=h_max_iter,
h_stop_condition=h_stop_condition,
eval_every=eval_every,
normalize=normalize,
random_state=random_state)
self.model = nmf_model
self.dictionary = dictionary
self.corpus_predictions = nmf_model[corpus]
return 'success'
# Create a list of the topic numbers we want to try
topic_nums = list(np.arange(5, 75 + 1, 5))
# Run the nmf model and calculate the coherence score
# for each number of topics
coherence_scores = []
for i in tqdm(range(0, len(topic_nums))):
for num in topic_nums:
nmf = Nmf(corpus=corpus,
num_topics=num,
id2word=dictionary,
chunksize=2000,
passes=5,
kappa=.1,
minimum_probability=0.01,
w_max_iter=300,
w_stop_condition=0.0001,
h_max_iter=100,
h_stop_condition=0.001,
eval_every=10,
normalize=True,
random_state=42)
time.sleep(0.5)
# Run the coherence model to get the score
cm = CoherenceModel(model=nmf,
texts=texts,
dictionary=dictionary,
coherence='c_v')
coherence_scores.append(round(cm.get_coherence(), 5))
# TODO Several useful descriptive insight methods in this article
# https://www.machinelearningplus.com/nlp/topic-modeling-gensim-python/#15visualizethetopicskeywords
# https://www.machinelearningplus.com/nlp/topic-modeling-visualization-how-to-present-results-lda-models/#14.-pyLDAVis
if not os.path.exists("img"):
os.mkdir("img")
#####################################################################################
# Wordcloud by topic
#####################################################################################
# Load model(s)
# lda = LdaModel.load("models/lda")
dct = gensim.utils.SaveLoad.load("models/dct")
corpus = gensim.corpora.MmCorpus("models/corpus")
nmf = Nmf.load("models/nmf")
# Generate word cloud for final model
labels = {
1: "Economic activity",
2: "Policy action",
3: "Economic outlook",
4: " Employment",
5: "Financial Markets",
6: "Inflation"
}
for topic in range(0, NUM_TOPICS):
termsnmf = nmf.show_topic(topic, topn=50)
# Model returns list of tuples, wordcloud wants a dictionary instead
wordcloudnmf = WordCloud(
background_color="white").generate_from_frequencies(dict(termsnmf))
def nmf_coherence_scores(text_l, min_df, max_df):
'''
Build Gensim NMF model, calculate coherence scores for various numbers of topics,
and plot coherence scores against number of topics
'''
texts = [word_tokenize(text) for text in text_l]
# Create a dictionary
dictionary = corpora.Dictionary(texts)
# Filter out extremes to limit the number of features
dictionary.filter_extremes(
no_below=min_df,
no_above=max_df
)
# Create the bag-of-words format (list of (token_id, token_count))
corpus = [dictionary.doc2bow(text) for text in texts]
# Create a list of the topic numbers we want to try
topic_nums = list(np.arange(5, 75 + 1, 5))
# Run NMF model and calculate coherence score for each number of topics
coherence_scores = []
for num in topic_nums:
nmf = Nmf(
corpus=corpus,
num_topics=num,
id2word=dictionary,
chunksize=2000,
passes=5,
kappa=.1,
minimum_probability=0.01,
w_max_iter=300,
w_stop_condition=0.0001,
h_max_iter=100,
h_stop_condition=0.001,
eval_every=10,
normalize=True,
random_state=42
)
cm = CoherenceModel(
model=nmf,
texts=texts,
dictionary=dictionary,
coherence='c_v'
)
coherence_scores.append(round(cm.get_coherence(), 5))
# Get the number of topics with the highest coherence score
scores = list(zip(topic_nums, coherence_scores))
best_num_topics = sorted(scores, key=operator.itemgetter(1), reverse=True)[0][0]
print(scores)
print(best_num_topics)
# Plot coherence scores
plt.figure(figsize=(8,5))
plt.plot(topic_nums, coherence_scores, color='r', linewidth=2)
plt.title('NMF Model Optimization: Coherence Scores', fontsize=16)
plt.xlabel('Number of topics', fontsize=14)
plt.ylabel('Coherence score', fontsize=14)
plt.xticks(np.arange(5,80,5), fontsize=12)
plt.yticks(fontsize=12)
plt.show()