Generating Word Cloud in R Programming
Word Cloud is a data visualization technique used for representing text data in which the size of each word indicates its frequency or importance. Significant textual data points can be highlighted using a word cloud. Word clouds are widely used for analyzing data from social network websites.
Why Word Cloud?
The reasons one should use word clouds to present the text data are:
- Word clouds add simplicity and clarity. The most used keywords stand out better in a word cloud
- Word clouds are a potent communication tool. They are easy to understand, to be shared, and are impactful.
- Word clouds are visually engaging than a table data.
Implementation in R
Here are steps to create a word cloud in R Programming.
Step 1: Create a Text File
Copy and paste the text in a plain text file (e.g:file.txt) and save the file.
Step 2: Install and Load the Required Packages
# install the required packages
install.packages("tm") # for text mining
install.packages("SnowballC") # for text stemming
install.packages("wordcloud") # word-cloud generator
install.packages("RColorBrewer") # color palettes
# load the packages
library("tm")
library("SnowballC")
library("wordcloud")
library("RColorBrewer")
Step 3: Text Mining
- Load the Text:
The text is loaded using Corpus() function from text mining(tm) package. Corpus is a list of a document.- Start by importing text file created in step 1:
To import the file saved locally in your computer, type the following R code. You will be asked to choose the text file interactively.Python3 text = readLines(file.choose())
Load the data as a corpus:Python3 # VectorSource() function # creates a corpus of # character vectors docs = Corpus(VectorSource(text))
Text transformation:
Transformation is performed using tm_map() function to replace, for example, special characters from the text like “@”, “#”, “/”.Python3 toSpace = content_transformer (function (x, pattern) gsub(pattern, " ", x)) docs1 = tm_map(docs, toSpace, "/") docs1 = tm_map(docs, toSpace, "@") docs1 = tm_map(docs, toSpace, "#")
- Start by importing text file created in step 1:
- Cleaning the Text:
The tm_map() function is used to remove unnecessary white space, to convert the text to lower case, to remove common stopwords. Numbers can be removed using removeNumbers.
Python3 # Convert the text to lower case docs1 = tm_map(docs1, content_transformer(tolower)) # Remove numbers docs1 = tm_map(docs1, removeNumbers) # Remove white spaces docs1 = tm_map(docs1, stripWhitespace)
Step 4: Build a term-document Matrix
Document matrix is a table containing the frequency of the words. Column names are words and row names are documents. The function TermDocumentMatrix() from text mining package can be used as follows.
dtm = TermDocumentMatrix(docs)
m = as.matrix(dtm)
v = sort(rowSums(m), decreasing = TRUE)
d = data.frame(word = names(v), freq = v)
head(d, 10)
Step 5: Generate the Word Cloud
The importance of words can be illustrated as a word cloud as follows.
wordcloud(words = d$word,
freq = d$freq,
min.freq = 1,
max.words = 200,
random.order = FALSE,
rot.per = 0.35,
colors = brewer.pal(8, "Dark2"))
The complete code for the word cloud in R is given below.
# R program to illustrate
# Generating word cloud
# Install the required packages
install.packages("tm") # for text mining
install.packages("SnowballC") # for text stemming
install.packages("wordcloud") # word-cloud generator
install.packages("RColorBrewer") # color palettes
# Load the packages
library("tm")
library("SnowballC")
library("wordcloud")
library("RColorBrewer")
# To choose the text file
text = readLines(file.choose())
# VectorSource() function
# creates a corpus of
# character vectors
docs = Corpus(VectorSource(text))
# Text transformation
toSpace = content_transformer(
function (x, pattern)
gsub(pattern, " ", x))
docs1 = tm_map(docs, toSpace, "/")
docs1 = tm_map(docs, toSpace, "@")
docs1 = tm_map(docs, toSpace, "#")
strwrap(docs1)
# Cleaning the Text
docs1 = tm_map(docs1, content_transformer(tolower))
docs1 = tm_map(docs1, removeNumbers)
docs1 = tm_map(docs1, stripWhitespace)
# Build a term-document matrix
dtm = TermDocumentMatrix(docs)
m = as.matrix(dtm)
v = sort(rowSums(m),
decreasing = TRUE)
d = data.frame(word = names(v),
freq = v)
head(d, 10)
# Generate the Word cloud
wordcloud(words = d$word,
freq = d$freq,
min.freq = 1,
max.words = 200,
random.order = FALSE,
rot.per = 0.35,
colors = brewer.pal(8, "Dark2"))
Output:
Advantages of Word Clouds
- Analyzing customer and employee feedback.
- Identifying new SEO keywords to target.
- Word clouds are killer visualisation tools. They present text data in a simple and clear format
- Word clouds are great communication tools. They are incredibly handy for anyone wishing to communicate a basic insight
Drawbacks of Word Clouds
- Word Clouds are not perfect for every situation.
- Data should be optimized for context.
- Word clouds typically fail to give the actionable insights that needs to improve and grow the business.
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