public void estimate(
InstanceList documents,
int numIterations,
int showTopicsInterval,
int outputModelInterval,
String outputModelFilename,
Randoms r) {
ilist = documents.shallowClone();
numTypes = ilist.getDataAlphabet().size();
int numDocs = ilist.size();
topics = new int[numDocs][];
docTopicCounts = new int[numDocs][numTopics];
typeTopicCounts = new int[numTypes][numTopics];
tokensPerTopic = new int[numTopics];
tAlpha = alpha * numTopics;
vBeta = beta * numTypes;
long startTime = System.currentTimeMillis();
// Initialize with random assignments of tokens to topics
// and finish allocating this.topics and this.tokens
int topic, seqLen;
FeatureSequence fs;
for (int di = 0; di < numDocs; di++) {
try {
fs = (FeatureSequence) ilist.get(di).getData();
} catch (ClassCastException e) {
System.err.println(
"LDA and other topic models expect FeatureSequence data, not FeatureVector data. "
+ "With text2vectors, you can obtain such data with --keep-sequence or --keep-bisequence.");
throw e;
}
seqLen = fs.getLength();
numTokens += seqLen;
topics[di] = new int[seqLen];
// Randomly assign tokens to topics
for (int si = 0; si < seqLen; si++) {
topic = r.nextInt(numTopics);
topics[di][si] = topic;
docTopicCounts[di][topic]++;
typeTopicCounts[fs.getIndexAtPosition(si)][topic]++;
tokensPerTopic[topic]++;
}
}
this.estimate(
0, numDocs, numIterations, showTopicsInterval, outputModelInterval, outputModelFilename, r);
// 124.5 seconds
// 144.8 seconds after using FeatureSequence instead of tokens[][] array
// 121.6 seconds after putting "final" on FeatureSequence.getIndexAtPosition()
// 106.3 seconds after avoiding array lookup in inner loop with a temporary variable
}
