Including simplex dropout

examples/twenty_newsgroups/lda2vec/lda2vec_model.py

@@ -13,9 +13,9 @@ class LDA2Vec(Chain):
     def __init__(self, n_documents=100, n_document_topics=10,
                  n_units=256, n_vocab=1000, dropout_ratio=0.5, train=True,
                  counts=None, n_samples=15, word_dropout_ratio=0.0,
-                 power=0.75):
+                 power=0.75, temperature=1.0):
         em = EmbedMixture(n_documents, n_document_topics, n_units,
-                          dropout_ratio=dropout_ratio)
+                          dropout_ratio=dropout_ratio, temperature=temperature)
         kwargs = {}
         kwargs['mixture'] = em
         kwargs['sampler'] = L.NegativeSampling(n_units, counts, n_samples,

examples/twenty_newsgroups/lda2vec/lda2vec_run.py

@@ -49,6 +49,8 @@
 power = float(os.getenv('power', 0.75))
 # Intialize with pretrained word vectors
 pretrained = bool(int(os.getenv('pretrained', True)))
+# Sampling temperature
+temperature = float(os.getenv('temperature', 1.0))
 # Number of dimensions in a single word vector
 n_units = int(os.getenv('n_units', 300))
 # Get the string representation for every compact key
@@ -69,7 +71,7 @@
 
 model = LDA2Vec(n_documents=n_docs, n_document_topics=n_topics,
                 n_units=n_units, n_vocab=n_vocab, counts=term_frequency,
-                n_samples=15, power=power)
+                n_samples=15, power=power, temperature=temperature)
 if os.path.exists('lda2vec.hdf5'):
     print "Reloading from saved"
     serializers.load_hdf5("lda2vec.hdf5", model)
@@ -91,11 +93,12 @@
                           cuda.to_cpu(model.sampler.W.data).copy(),
                           words)
     top_words = print_top_words_per_topic(data)
-    coherence = topic_coherence(top_words)
-    for j in range(n_topics):
-        print j, coherence[(j, 'cv')]
-    kw = dict(top_words=top_words, coherence=coherence, epoch=epoch)
-    progress[str(epoch)] = pickle.dumps(kw)
+    if j % 100 == 0 and j > 100:
+        coherence = topic_coherence(top_words)
+        for j in range(n_topics):
+            print j, coherence[(j, 'cv')]
+        kw = dict(top_words=top_words, coherence=coherence, epoch=epoch)
+        progress[str(epoch)] = pickle.dumps(kw)
     data['doc_lengths'] = doc_lengths
     data['term_frequency'] = term_frequency
     np.savez('topics.pyldavis', **data)

lda2vec/embed_mixture.py

@@ -3,6 +3,7 @@
 import chainer
 import chainer.links as L
 import chainer.functions as F
+from chainer import Variable
 
 
 def _orthogonal_matrix(shape):
@@ -60,7 +61,8 @@ class EmbedMixture(chainer.Chain):
     .. seealso:: :func:`lda2vec.dirichlet_likelihood`
     """
 
-    def __init__(self, n_documents, n_topics, n_dim, dropout_ratio=0.2):
+    def __init__(self, n_documents, n_topics, n_dim, dropout_ratio=0.2,
+                 temperature=1.0):
         self.n_documents = n_documents
         self.n_topics = n_topics
         self.n_dim = n_dim
@@ -70,6 +72,7 @@ def __init__(self, n_documents, n_topics, n_dim, dropout_ratio=0.2):
         super(EmbedMixture, self).__init__(
             weights=L.EmbedID(n_documents, n_topics),
             factors=L.Parameter(factors))
+        self.temperature = temperature
         self.weights.W.data[...] /= np.sqrt(n_documents + n_topics)
 
     def __call__(self, doc_ids, update_only_docs=False):
@@ -102,5 +105,13 @@ def proportions(self, doc_ids, softmax=False):
             doc_weights : chainer.Variable
                 Two dimensional topic weights of each document.
         """
-        w = F.dropout(self.weights(doc_ids), ratio=self.dropout_ratio)
-        return F.softmax(w) if softmax else w
+        w = self.weights(doc_ids)
+        if softmax:
+            size = w.data.shape
+            mask = self.xp.random.random_integers(0, 1, size=size)
+            y = (F.softmax(w * self.temperature) *
+                 Variable(mask.astype('float32')))
+            norm, y = F.broadcast(F.expand_dims(F.sum(y, axis=1), 1), y)
+            return y / (norm + 1e-7)
+        else:
+            return w