/*
 *  * Copyright 2016 Skymind, Inc.
 *  *
 *  *    Licensed under the Apache License, Version 2.0 (the "License");
 *  *    you may not use this file except in compliance with the License.
 *  *    You may obtain a copy of the License at
 *  *
 *  *        http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  *    Unless required by applicable law or agreed to in writing, software
 *  *    distributed under the License is distributed on an "AS IS" BASIS,
 *  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  *    See the License for the specific language governing permissions and
 *  *    limitations under the License.
 */

package org.datavec.nlp.vectorizer;

import org.datavec.api.conf.Configuration;
import org.datavec.api.records.reader.RecordReader;
import org.datavec.api.writable.Writable;
import org.datavec.nlp.tokenization.tokenizer.Tokenizer;
import org.datavec.nlp.tokenization.tokenizerfactory.DefaultTokenizerFactory;
import org.datavec.nlp.tokenization.tokenizerfactory.TokenizerFactory;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

/**
 * Tf idf vectorizer
 * @author Adam Gibson
 */
public abstract class AbstractTfidfVectorizer<VECTOR_TYPE> extends TextVectorizer<VECTOR_TYPE> {

    @Override
    public void doWithTokens(Tokenizer tokenizer) {
        Set<String> seen = new HashSet<>();
        while(tokenizer.hasMoreTokens()) {
            String token = tokenizer.nextToken();
            cache.incrementCount(token);
            if(!seen.contains(token)) {
                cache.incrementDocCount(token);
            }
            seen.add(token);
        }
    }

    @Override
    public TokenizerFactory createTokenizerFactory(Configuration conf) {
        String clazz = conf.get(TOKENIZER,DefaultTokenizerFactory.class.getName());
        try {
            Class<? extends TokenizerFactory> tokenizerFactoryClazz = (Class<? extends TokenizerFactory>) Class.forName(clazz);
            return tokenizerFactoryClazz.newInstance();
        } catch (Exception e) {
           throw new RuntimeException(e);
        }
    }

    @Override
    public abstract VECTOR_TYPE createVector(Object[] args);

    @Override
    public abstract VECTOR_TYPE fitTransform(RecordReader reader);

    @Override
    public abstract VECTOR_TYPE transform(Collection<Writable> record);
}

/*
 *  * Copyright 2016 Skymind, Inc.
 *  *
 *  *    Licensed under the Apache License, Version 2.0 (the "License");
 *  *    you may not use this file except in compliance with the License.
 *  *    You may obtain a copy of the License at
 *  *
 *  *        http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  *    Unless required by applicable law or agreed to in writing, software
 *  *    distributed under the License is distributed on an "AS IS" BASIS,
 *  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  *    See the License for the specific language governing permissions and
 *  *    limitations under the License.
 */

package org.datavec.nlp.vectorizer;

import org.datavec.api.conf.Configuration;
import org.datavec.api.records.reader.RecordReader;
import org.datavec.api.writable.Writable;
import org.datavec.nlp.tokenization.tokenizer.Tokenizer;
import org.datavec.nlp.tokenization.tokenizerfactory.DefaultTokenizerFactory;
import org.datavec.nlp.tokenization.tokenizerfactory.TokenizerFactory;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

/**
 * Tf idf vectorizer
 * @author Adam Gibson
 */
public abstract class AbstractTfidfVectorizer<VECTOR_TYPE> extends TextVectorizer<VECTOR_TYPE> {

    @Override
    public void doWithTokens(Tokenizer tokenizer) {
        Set<String> seen = new HashSet<>();
        while(tokenizer.hasMoreTokens()) {
            String token = tokenizer.nextToken();
            if(!stopWords.contains(token)) {
                cache.incrementCount(token);
                if (!seen.contains(token)) {
                    cache.incrementDocCount(token);
                }
                seen.add(token);
            }
        }
    }

    @Override
    public TokenizerFactory createTokenizerFactory(Configuration conf) {
        String clazz = conf.get(TOKENIZER,DefaultTokenizerFactory.class.getName());
        try {
            Class<? extends TokenizerFactory> tokenizerFactoryClazz = (Class<? extends TokenizerFactory>) Class.forName(clazz);
            return tokenizerFactoryClazz.newInstance();
        } catch (Exception e) {
           throw new RuntimeException(e);
        }
    }

    @Override
    public abstract VECTOR_TYPE createVector(Object[] args);

    @Override
    public abstract VECTOR_TYPE fitTransform(RecordReader reader);

    @Override
    public abstract VECTOR_TYPE transform(Collection<Writable> record);
}

Use StopWords