星火MLLib TFIDF实施逻辑回归 [英] Spark MLLib TFIDF implementation for LogisticRegression
问题描述
我尝试使用新的TFIDF算法用于火花1.1.0优惠。我在写我的MLLib在Java中的工作,但我无法弄清楚如何获得TFIDF实施工作。出于某种原因, IDFModel 只接受 JavaRDD 一>作为用于该方法的输入<一href=\"http://spark.apache.org/docs/latest/api/java/org/apache/spark/mllib/feature/IDFModel.html#transform%28org.apache.spark.api.java.JavaRDD%29\"相对=nofollow>变换而不是简单的矢量。 如何使用给定的类到TFIDF向量为我LabledPoints模型?
的注:文件行格式[标签;文字] 的
下面我code迄今:
// 1)加载文件
JavaRDD&LT;串GT;数据= sc.textFile(/家庭/约翰尼/ data.data.new); // 2)散列的所有文件
HashingTF TF =新HashingTF();
JavaRDD&LT; Tuple2&LT;四,向量&GT;&GT; tupleData = Data.Map中(新功能与LT;弦乐,Tuple2&LT;四,向量&GT;&GT;(){
@覆盖
公共Tuple2&LT;四,向量&GT;调用(字符串V1)抛出异常{
的String []数据= v1.split();
清单&LT;串GT; myList中= Arrays.asList(数据[1] .split());
返回新Tuple2&LT;四,向量&GT;(Double.parseDouble(数据[0]),tf.transform(myList中));
}
}); tupleData.cache(); // 3)与所有矢量创建平面RDD
JavaRDD&LT;向量&GT; hashedData = tupleData.map(新功能&LT; Tuple2&LT;双,矢量&gt;中矢量&GT;(){
@覆盖
公共向量调用(Tuple2&LT;四,向量&GT; V1)抛出异常{
返回v1._2;
}
}); // 4)创建一个IDFModel我们平矢量RDD的
IDFModel idfModel =新IDF()配合(hashedData)。 // 5)与TFIDF创建Labledpoint RDD
???
解决方案 肖恩·欧文的:
// 1)加载文件
JavaRDD&LT;串GT;数据= sc.textFile(/家庭/约翰尼/ data.data.new); // 2)散列的所有文件
HashingTF TF =新HashingTF();
JavaRDD&LT; LabeledPoint&GT; tupleData = Data.Map中(V1 - &GT; {
的String [] = DATAS v1.split();
清单&LT;串GT; myList中= Arrays.asList(DATAS [1] .split());
返回新LabeledPoint(Double.parseDouble(DATAS [0]),tf.transform(myList中));
});
// 3)与所有矢量创建平面RDD
JavaRDD&LT;向量&GT; hashedData = tupleData.map(标签 - &GT; label.features());
// 4)创建一个IDFModel我们平矢量RDD的
IDFModel idfModel =新IDF()配合(hashedData)。
// 5)创建TFIDF RDD
JavaRDD&LT;向量&GT; IDF = idfModel.transform(hashedData);
// 6.)创建Labledpoint RDD
JavaRDD&LT; LabeledPoint&GT; idfTransformed = idf.zip(tupleData).MAP(T - &GT; {
返回新LabeledPoint(t._2.label(),t._1);
});
IDFModel.transform()
接受 JavaRDD
或 RDD
矢量
,如你所见。它没有意义的,在计算模型的单一矢量
,所以这不是你要找的内容吧?
我假设你用Java开发的,所以你的意思是要将此应用到 JavaRDD&LT; LabeledPoint&GT;
。 LabeledPoint
包含矢量
和标签。 IDF不是一个分类或回归,因此它需要无标签。您可以地图
一堆 LabeledPoint
的只是提取其矢量
。
但你已经有一个 JavaRDD&LT;载体&gt;中
。 TF-IDF是仅仅映射词基于在语料库词频实值特征的一种方法。它也不输出标签。也许你的意思是你想开发的TF-IDF衍生的特征向量,并且你已经有一些其他标签分类器?
也许这将清除的东西了,但是,否则你必须清晰地阐明您正试图实现与TF-IDF的东西。
I try to use the new TFIDF algorithem that spark 1.1.0 offers. I'm writing my job for MLLib in Java but I can't figure out how to get the TFIDF implementation working. For some reason IDFModel only accepts a JavaRDD as input for the method transform and not simple Vector. How can I use the given classes to model a TFIDF vector for my LabledPoints?
Note: The document lines are in the format [Label; Text]
Here my code so far:
// 1.) Load the documents
JavaRDD<String> data = sc.textFile("/home/johnny/data.data.new");
// 2.) Hash all documents
HashingTF tf = new HashingTF();
JavaRDD<Tuple2<Double, Vector>> tupleData = data.map(new Function<String, Tuple2<Double, Vector>>() {
@Override
public Tuple2<Double, Vector> call(String v1) throws Exception {
String[] data = v1.split(";");
List<String> myList = Arrays.asList(data[1].split(" "));
return new Tuple2<Double, Vector>(Double.parseDouble(data[0]), tf.transform(myList));
}
});
tupleData.cache();
// 3.) Create a flat RDD with all vectors
JavaRDD<Vector> hashedData = tupleData.map(new Function<Tuple2<Double,Vector>, Vector>() {
@Override
public Vector call(Tuple2<Double, Vector> v1) throws Exception {
return v1._2;
}
});
// 4.) Create a IDFModel out of our flat vector RDD
IDFModel idfModel = new IDF().fit(hashedData);
// 5.) Create Labledpoint RDD with TFIDF
???
Solution from Sean Owen:
// 1.) Load the documents
JavaRDD<String> data = sc.textFile("/home/johnny/data.data.new");
// 2.) Hash all documents
HashingTF tf = new HashingTF();
JavaRDD<LabeledPoint> tupleData = data.map(v1 -> {
String[] datas = v1.split(";");
List<String> myList = Arrays.asList(datas[1].split(" "));
return new LabeledPoint(Double.parseDouble(datas[0]), tf.transform(myList));
});
// 3.) Create a flat RDD with all vectors
JavaRDD<Vector> hashedData = tupleData.map(label -> label.features());
// 4.) Create a IDFModel out of our flat vector RDD
IDFModel idfModel = new IDF().fit(hashedData);
// 5.) Create tfidf RDD
JavaRDD<Vector> idf = idfModel.transform(hashedData);
// 6.) Create Labledpoint RDD
JavaRDD<LabeledPoint> idfTransformed = idf.zip(tupleData).map(t -> {
return new LabeledPoint(t._2.label(), t._1);
});
IDFModel.transform()
accepts a JavaRDD
or RDD
of Vector
, as you see. It does not make sense to compute a model over a single Vector
, so that's not what you're looking for right?
I assume you're working in Java, so you mean you want to apply this to a JavaRDD<LabeledPoint>
. LabeledPoint
contains a Vector
and a label. IDF is not a classifier or regressor, so it needs no label. You can map
a bunch of LabeledPoint
to just extract their Vector
.
But you already have a JavaRDD<Vector>
above. TF-IDF is merely a way of mapping words to real-valued features based on word frequencies in the corpus. It also does not output a label. Maybe you mean you want to develop a classifier from TF-IDF-derived feature vectors, and some other labels you already have?
Maybe that clears things up but otherwise you'd have to greatly clarify what you are trying to achieve with TF-IDF.
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