Book Image

Mastering Text Mining with R

By : KUMAR ASHISH
Book Image

Mastering Text Mining with R

By: KUMAR ASHISH

Overview of this book

Text Mining (or text data mining or text analytics) is the process of extracting useful and high-quality information from text by devising patterns and trends. R provides an extensive ecosystem to mine text through its many frameworks and packages. Starting with basic information about the statistics concepts used in text mining, this book will teach you how to access, cleanse, and process text using the R language and will equip you with the tools and the associated knowledge about different tagging, chunking, and entailment approaches and their usage in natural language processing. Moving on, this book will teach you different dimensionality reduction techniques and their implementation in R. Next, we will cover pattern recognition in text data utilizing classification mechanisms, perform entity recognition, and develop an ontology learning framework. By the end of the book, you will develop a practical application from the concepts learned, and will understand how text mining can be leveraged to analyze the massively available data on social media.
Table of Contents (15 chapters)

Correspondence analysis


Just like PCA, the basic idea behind correspondence analysis is to reduce the dimensionality of data and represent it in a low-dimensionality space. Correspondence analysis basically deals with contingency tables or cross tabs. This technique is designed to perform exploratory analysis on multi-way tables with some degree of correspondence between their dimensions. The common methodology followed for correspondence analysis involves the standardization of the cross tab table of frequencies so that the entries in the cross tab can be represented in terms of distance between the dimensions in a low-dimensional space.

There are a few packages available in R that provide efficient functions for correspondence analysis:

R functions

Package

ca()

ca

corresp(formula,nf,data)

MASS

dudi.coa(df, scannf = TRUE, nf = 2)

ade4

CA()

FactorMineR

afc()

amap

Let's look at an example application of the R functions for simple correspondence analysis:

# Load...