SentimentCoreAnnotations returns null

[warpech]

Hi! I have managed to run the examples on the website, but I am missing an example for sentiment analysis. I have found an example here: http://stackoverflow.com/questions/31832387/using-stanford-nlp-lib-in-c-sharp-while-trying-to-get-sentiment-positive-nega, but it doesn't work for me.

After adapting it to a C# class, I ended up with code that compiles:

using System;

namespace PureCS {
    class Program {
        static void Main() {
            var sentimentHelper = new SentimentHelper();
            var sentiment = sentimentHelper.Analyze("This is freaking awesome!");
        }
    }
}

using edu.stanford.nlp.ling;
using edu.stanford.nlp.neural.rnn;
using edu.stanford.nlp.pipeline;
using edu.stanford.nlp.sentiment;
using edu.stanford.nlp.trees;
using edu.stanford.nlp.util;
using java.io;
using java.text;
using java.util;
using System;
using System.IO;

namespace PureCS {
    public class StanfordNLPModelNotFoundExpection : Exception {
    }

    public class SentimentHelper {
        private string jarRoot;
        public string LastError;

        public SentimentHelper() {
            //JarRoot = @"..\..\..\..\paket-files\nlp.stanford.edu\stanford-corenlp-full-2015-12-09\models";
            jarRoot = "C:\\www\\warpech\\Crystal\\stanford-corenlp-full-2015-12-09\\stanford-corenlp-3.6.0-models";

            if (Directory.Exists(jarRoot) == false) {
                LastError = typeof(StanfordNLPModelNotFoundExpection).Name;
            }
        }

        public int Analyze(string text) {
            var result = "";

            // Annotation pipeline configuration
            var props = new java.util.Properties();

            props.setProperty("annotators", "tokenize, ssplit, pos, lemma, ner, parse, dcoref");
            //props.setProperty("sutime.binders", "0");
            //props.setProperty("ner.useSUTime", "false");
            props.setProperty("ner.useSUTime", "0");

            // We should change current directory, so D:\Core NLP Files\stanford-corenlp-full-2015-04-20\stanford-corenlp-full-2015-04-20 could find all the model files automatically
            var curDir = Environment.CurrentDirectory;
            Directory.SetCurrentDirectory(jarRoot);
            var pipeline = new StanfordCoreNLP(props);
            Directory.SetCurrentDirectory(curDir);

            // Annotation
            var annotation = new edu.stanford.nlp.pipeline.Annotation(text);
            pipeline.annotate(annotation);

            // Result - Pretty Print
            using (var stream = new ByteArrayOutputStream()) {
                pipeline.prettyPrint(annotation, new PrintWriter(stream));

                //Analyze the statement as positive or negative
                int mainSentiment = 0;
                int longest = 0;
                String[] sentimentText = { "Very Negative", "Negative", "Neutral", "Positive", "Very Positive" };

                NumberFormat NF = new DecimalFormat("0.0000");

                var sentences = annotation.get(new CoreAnnotations.SentencesAnnotation().getClass()) as ArrayList;

                foreach (CoreMap sentence in sentences) {
                    Tree tree = sentence.get(new SentimentCoreAnnotations.SentimentAnnotatedTree().getClass()) as Tree;

                    int sentiment = RNNCoreAnnotations.getPredictedClass(tree);

                    String partText = sentence.ToString();
                    result += "Sentence: '" + partText + "' is rather " + sentimentText[sentiment] + ". ";

                    if (partText.Length > longest) {
                        mainSentiment = sentiment;
                        longest = partText.Length;
                    }
                }

                if (mainSentiment == 2 || mainSentiment > 4 || mainSentiment < 0) {
                    result += "Overall it was sort of neutral review";
                }
                else if (mainSentiment > 2) {
                    result += "Overall we are happy";
                }
                else {
                    result += "Bottom line. We are displeased";
                }

                stream.close();
                return mainSentiment;
            }

        }
    }
}

The problem that I have is that this line returns null:

Tree tree = sentence.get(new SentimentCoreAnnotations.SentimentAnnotatedTree().getClass()) as Tree;

[warpech]

Screenshot:

[warpech]

Leave me alone and I will figure it out :) The problem was that I didn't load the sentiment annotator.

Instead of:

props.setProperty("annotators", "tokenize, ssplit, pos, lemma, ner, parse, dcoref");

Should be:

props.setProperty("annotators", "tokenize, ssplit, parse, sentiment");

[sergey-tihon]

Cool, this demo may be also interesting to you https://github.com/evelinag/SentimentAnalysisDemo

[warpech]

Thanks! It's really helpful