Text Mining and Sentiment Analysis in R

Sanil Mhatre walks us through a sentiment analysis scenario in R:

Sentiments can be classified as positive, neutral or negative. They can also be represented on a numeric scale, to better express the degree of positive or negative strength of the sentiment contained in a body of text.

This example uses the Syuzhet package for generating sentiment scores, which has four sentiment dictionaries and offers a method for accessing the sentiment extraction tool developed in the NLP group at Stanford. The get_sentiment function accepts two arguments: a character vector (of sentences or words) and a method. The selected method determines which of the four available sentiment extraction methods will be used. The four methods are syuzhet (this is the default), bing, afinn and nrc. Each method uses a different scale and hence returns slightly different results. Please note the outcome of nrc method is more than just a numeric score, requires additional interpretations and is out of scope for this article. The descriptions of the get_sentiment function has been sourced from : https://cran.r-project.org/web/packages/syuzhet/vignettes/syuzhet-vignette.html?