Type Members

1.  class PragmaticScorer extends Serializable

   Scorer is a rule based implementation inspired on http://fjavieralba.com/basic-sentiment-analysis-with-python.html Its strategy is to tag words by a dictionary in a sentence context, and later identify such context to get amplifiers

2.  class SentimentDetector extends AnnotatorApproach[SentimentDetectorModel]

   Trains a rule based sentiment detector, which calculates a score based on predefined keywords.

   Trains a rule based sentiment detector, which calculates a score based on predefined keywords.

   A dictionary of predefined sentiment keywords must be provided with setDictionary, where each line is a word delimited to its class (either positive or negative). The dictionary can be set in either in the form of a delimited text file or directly as an ExternalResource.

   By default, the sentiment score will be assigned labels "positive" if the score is >= 0, else "negative". To retrieve the raw sentiment scores, enableScore needs to be set to true.

   For extended examples of usage, see the Examples and the SentimentTestSpec.

   Example

   In this example, the dictionary default-sentiment-dict.txt has the form of

   ...
   cool,positive
   superb,positive
   bad,negative
   uninspired,negative
   ...

   where each sentiment keyword is delimited by ",".

   import spark.implicits._
   import com.johnsnowlabs.nlp.DocumentAssembler
   import com.johnsnowlabs.nlp.annotator.Tokenizer
   import com.johnsnowlabs.nlp.annotators.Lemmatizer
   import com.johnsnowlabs.nlp.annotators.sda.pragmatic.SentimentDetector
   import com.johnsnowlabs.nlp.util.io.ReadAs
   import org.apache.spark.ml.Pipeline
   
   val documentAssembler = new DocumentAssembler()
     .setInputCol("text")
     .setOutputCol("document")
   
   val tokenizer = new Tokenizer()
     .setInputCols("document")
     .setOutputCol("token")
   
   val lemmatizer = new Lemmatizer()
     .setInputCols("token")
     .setOutputCol("lemma")
     .setDictionary("src/test/resources/lemma-corpus-small/lemmas_small.txt", "->", "\t")
   
   val sentimentDetector = new SentimentDetector()
     .setInputCols("lemma", "document")
     .setOutputCol("sentimentScore")
     .setDictionary("src/test/resources/sentiment-corpus/default-sentiment-dict.txt", ",", ReadAs.TEXT)
   
   val pipeline = new Pipeline().setStages(Array(
     documentAssembler,
     tokenizer,
     lemmatizer,
     sentimentDetector,
   ))
   
   val data = Seq(
     "The staff of the restaurant is nice",
     "I recommend others to avoid because it is too expensive"
   ).toDF("text")
   val result = pipeline.fit(data).transform(data)
   
   result.selectExpr("sentimentScore.result").show(false)
   +----------+  //  +------+ for enableScore set to true
   |result    |  //  |result|
   +----------+  //  +------+
   |[positive]|  //  |[1.0] |
   |[negative]|  //  |[-2.0]|
   +----------+  //  +------+

   See also

   ViveknSentimentApproach for an alternative approach to sentiment extraction

3.  class SentimentDetectorModel extends AnnotatorModel[SentimentDetectorModel] with HasSimpleAnnotate[SentimentDetectorModel]

   Rule based sentiment detector, which calculates a score based on predefined keywords.

   Rule based sentiment detector, which calculates a score based on predefined keywords.

   This is the instantiated model of the SentimentDetector. For training your own model, please see the documentation of that class.

   A dictionary of predefined sentiment keywords must be provided with setDictionary, where each line is a word delimited to its class (either positive or negative). The dictionary can be set in either in the form of a delimited text file or directly as an ExternalResource.

   By default, the sentiment score will be assigned labels "positive" if the score is >= 0, else "negative". To retrieve the raw sentiment scores, enableScore needs to be set to true.

   For extended examples of usage, see the Examples and the SentimentTestSpec.

   See also

   ViveknSentimentApproach for an alternative approach to sentiment extraction