Example #1
0
    def testPerplexityOnRealData(self):
        dtype = np.float64 # DTYPE

        rd.seed(0xBADB055)
        data = DataSet.from_files(words_file=AclWordPath, links_file=AclCitePath)
        with open(AclDictPath, "rb") as f:
            d = pkl.load(f)

        data.convert_to_dtype(np.int32)
        data.prune_and_shuffle(min_doc_len=50, min_link_count=2)
        data.convert_to_undirected_graph()
        data.convert_to_binary_link_matrix()

        # IDF frequency for when we print out the vocab later
        freq = np.squeeze(np.asarray(data.words.sum(axis=0)))
        scale = np.reciprocal(1 + freq)

        # Initialise the model
        K = 10
        model      = lda.newModelAtRandom(data, K, dtype=dtype)
        queryState = lda.newQueryState(data, model)
        trainPlan  = lda.newTrainPlan(iterations=300, logFrequency=50, fastButInaccurate=False, debug=True)

        # Train the model, and the immediately save the result to a file for subsequent inspection
        model, query, (bndItrs, bndVals, bndLikes) = lda.train (data, model, queryState, trainPlan)
#        with open(newModelFileFromModel(model), "wb") as f:
#            pkl.dump ((model, query, (bndItrs, bndVals, bndLikes)), f)

        # Plot the evolution of the bound during training.
        fig, ax1 = plt.subplots()
        ax1.plot(bndItrs, bndVals, 'b-')
        ax1.set_xlabel('Iterations')
        ax1.set_ylabel('Bound', color='b')

        ax2 = ax1.twinx()
        ax2.plot(bndItrs, bndLikes, 'r-')
        ax2.set_ylabel('Likelihood', color='r')

        fig.show()
        plt.show()

        vocab = lda.wordDists(model)
        plt.imshow(vocab, interpolation="none", cmap = cm.Greys_r)
        plt.show()

        # Print out the most likely topic words
        topWordCount = 10
        kTopWordInds = [self.topWordInds(vocab[k,:], topWordCount) for k in range(K)]

        like = lda.log_likelihood(data, model, query)
        perp = perplexity_from_like(like, data.word_count)

        print ("Prior %s" % (str(model.topicPrior)))
        print ("Perplexity: %f\n\n" % perp)

        for k in range(model.K):
            print ("\nTopic %d\n=============================" % k)
            print ("\n".join("%-20s\t%0.4f" % (d[kTopWordInds[k][c]], vocab[k][kTopWordInds[k][c]]) for c in range(topWordCount)))
Example #2
0
    def testCrossValPerplexityOnRealDataWithLdaGibbsInc(self):
        ActiveFolds = 3
        dtype = np.float64 # DTYPE

        rd.seed(0xBADB055)
        data = DataSet.from_files(words_file=AclWordPath, links_file=AclCitePath)

        data.convert_to_dtype(np.int32) # Gibbs expects integers as input, regardless of model dtype
        data.prune_and_shuffle(min_doc_len=MinDocLen, min_link_count=MinLinkCount)

        # Training setup
        TrainSamplesPerTopic = 10
        QuerySamplesPerTopic = 2
        Thin = 2
        Debug = False

        # Start running experiments
        topicCounts = [5, 10, 15, 20, 25, 30, 35, 40, 45, 50]
        for K in topicCounts:
            trainPlan = lda_gibbs.newTrainPlan(K * TrainSamplesPerTopic, thin=Thin, debug=Debug)
            queryPlan = lda_gibbs.newTrainPlan(K * QuerySamplesPerTopic, thin=Thin, debug=Debug)

            trainPerps = []
            queryPerps = []
            for fold in range(ActiveFolds): # range(NumFolds):
                trainData, queryData = data.cross_valid_split(fold, NumFolds)
                estData, evalData = queryData.doc_completion_split()

                model = lda_gibbs.newModelAtRandom(trainData, K, dtype=dtype)
                query = lda_gibbs.newQueryState(trainData, model)

                # Train the model, and the immediately save the result to a file for subsequent inspection
                model, trainResult, (_, _, _) = lda_gibbs.train (trainData, model, query, trainPlan)

                like = lda_gibbs.log_likelihood(trainData, model, trainResult)
                perp = perplexity_from_like(like, trainData.word_count)
                trainPerps.append(perp)

                query = lda_gibbs.newQueryState(estData, model)
                _, queryResult = lda_gibbs.query(estData, model, query, queryPlan)

                like = lda_gibbs.log_likelihood(evalData, model, queryResult)
                perp = perplexity_from_like(like, evalData.word_count)
                queryPerps.append(perp)

            trainPerps.append(sum(trainPerps) / ActiveFolds)
            queryPerps.append(sum(queryPerps) / ActiveFolds)
            print("K=%d,Segment=Train,%s" % (K, ",".join([str(p) for p in trainPerps])))
            print("K=%d,Segment=Query,%s" % (K, ",".join([str(p) for p in queryPerps])))