public void trainDocuments(double testFraction) {
long start = System.nanoTime();
modelTrainer.start();
for (int docId = 0; docId < corpusWeights.numRows(); docId++) {
if (testFraction == 0 || docId % (1 / testFraction) != 0) {
Vector docTopics =
new DenseVector(numTopics).assign(1.0 / numTopics); // docTopicCounts.getRow(docId)
modelTrainer.trainSync(corpusWeights.viewRow(docId), docTopics, true, 10);
}
}
modelTrainer.stop();
logTime("train documents", System.nanoTime() - start);
}
public double iterateUntilConvergence(
double minFractionalErrorChange, int maxIterations, int minIter, double testFraction) {
int iter = 0;
double oldPerplexity = 0;
while (iter < minIter) {
trainDocuments(testFraction);
if (verbose) {
log.info("model after: " + iter + ": " + modelTrainer.getReadModel().toString());
}
log.info("iteration " + iter + " complete");
oldPerplexity = modelTrainer.calculatePerplexity(corpusWeights, docTopicCounts, testFraction);
log.info(oldPerplexity + " = perplexity");
iter++;
}
double newPerplexity = 0;
double fractionalChange = Double.MAX_VALUE;
while (iter < maxIterations && fractionalChange > minFractionalErrorChange) {
trainDocuments();
if (verbose) {
log.info("model after: " + iter + ": " + modelTrainer.getReadModel().toString());
}
newPerplexity = modelTrainer.calculatePerplexity(corpusWeights, docTopicCounts, testFraction);
log.info(newPerplexity + " = perplexity");
iter++;
fractionalChange = Math.abs(newPerplexity - oldPerplexity) / oldPerplexity;
log.info(fractionalChange + " = fractionalChange");
oldPerplexity = newPerplexity;
}
if (iter < maxIterations) {
log.info(
String.format(
"Converged! fractional error change: %f, error %f", fractionalChange, newPerplexity));
} else {
log.info(
String.format(
"Reached max iteration count (%d), fractional error change: %f, error: %f",
maxIterations, fractionalChange, newPerplexity));
}
return newPerplexity;
}
public void registerWithTrainer(ModelTrainer modelTrainer) {
modelTrainer.registerModel(delegate);
}
public void writeModel(Path outputPath) throws IOException {
modelTrainer.persist(outputPath);
}
