In Text Mining with R, Chapter 2 looks at Sentiment Analysis. In this assignment, you should start by getting the primary example code from chapter 2 working in an R Markdown document. You should provide a citation to this base code. You’re then asked to extend the code in two ways:
library(tidyverse)
## -- Attaching packages --------------------------------------- tidyverse 1.3.0 --
## v ggplot2 3.3.3 v purrr 0.3.4
## v tibble 3.0.6 v dplyr 1.0.4
## v tidyr 1.1.2 v stringr 1.4.0
## v readr 1.4.0 v forcats 0.5.1
## -- Conflicts ------------------------------------------ tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag() masks stats::lag()
library(tidytext)
## Warning: package 'tidytext' was built under R version 4.0.5
library(textdata)
## Warning: package 'textdata' was built under R version 4.0.5
library(janeaustenr)
## Warning: package 'janeaustenr' was built under R version 4.0.5
library(stringr)
library(wordcloud)
## Warning: package 'wordcloud' was built under R version 4.0.5
## Loading required package: RColorBrewer
library(reshape2)
## Warning: package 'reshape2' was built under R version 4.0.4
##
## Attaching package: 'reshape2'
## The following object is masked from 'package:tidyr':
##
## smiths
library(gutenbergr)
## Warning: package 'gutenbergr' was built under R version 4.0.5
get_sentiments("afinn")
## # A tibble: 2,477 x 2
## word value
## <chr> <dbl>
## 1 abandon -2
## 2 abandoned -2
## 3 abandons -2
## 4 abducted -2
## 5 abduction -2
## 6 abductions -2
## 7 abhor -3
## 8 abhorred -3
## 9 abhorrent -3
## 10 abhors -3
## # ... with 2,467 more rows
get_sentiments("bing")
## # A tibble: 6,786 x 2
## word sentiment
## <chr> <chr>
## 1 2-faces negative
## 2 abnormal negative
## 3 abolish negative
## 4 abominable negative
## 5 abominably negative
## 6 abominate negative
## 7 abomination negative
## 8 abort negative
## 9 aborted negative
## 10 aborts negative
## # ... with 6,776 more rows
get_sentiments("nrc")
## # A tibble: 13,901 x 2
## word sentiment
## <chr> <chr>
## 1 abacus trust
## 2 abandon fear
## 3 abandon negative
## 4 abandon sadness
## 5 abandoned anger
## 6 abandoned fear
## 7 abandoned negative
## 8 abandoned sadness
## 9 abandonment anger
## 10 abandonment fear
## # ... with 13,891 more rows
#words with a joy score from the NRC lexicon
tidy_books <- austen_books() %>%
group_by(book) %>%
mutate(
linenumber = row_number(),
chapter = cumsum(str_detect(text,
regex("^chapter [\\divxlc]",
ignore_case = TRUE)))) %>%
ungroup() %>%
unnest_tokens(word, text)
# Now that the text is in a tidy format with one word per row, we are ready to do the sentiment analysis
nrc_joy <- get_sentiments("nrc") %>%
filter(sentiment == "joy")
tidy_books %>%
filter(book == "Emma") %>%
inner_join(nrc_joy) %>%
count(word, sort = TRUE)
## Joining, by = "word"
## # A tibble: 303 x 2
## word n
## <chr> <int>
## 1 good 359
## 2 young 192
## 3 friend 166
## 4 hope 143
## 5 happy 125
## 6 love 117
## 7 deal 92
## 8 found 92
## 9 present 89
## 10 kind 82
## # ... with 293 more rows
# Next, we count up how many positive and negative words there are in defined sections of each book
jane_austen_sentiment <- tidy_books %>%
inner_join(get_sentiments("bing")) %>%
count(book, index = linenumber %/% 80, sentiment) %>%
pivot_wider(names_from = sentiment, values_from = n, values_fill = 0) %>%
mutate(sentiment = positive - negative)
## Joining, by = "word"
# Now we can plot these sentiment scores across the plot trajectory of each novel
ggplot(jane_austen_sentiment, aes(index, sentiment, fill = book)) +
geom_col(show.legend = FALSE) +
facet_wrap(~book, ncol = 2, scales = "free_x")
# Choose only the words from the one novel we are interested in
pride_prejudice <- tidy_books %>%
filter(book == "Pride & Prejudice")
pride_prejudice
## # A tibble: 122,204 x 4
## book linenumber chapter word
## <fct> <int> <int> <chr>
## 1 Pride & Prejudice 1 0 pride
## 2 Pride & Prejudice 1 0 and
## 3 Pride & Prejudice 1 0 prejudice
## 4 Pride & Prejudice 3 0 by
## 5 Pride & Prejudice 3 0 jane
## 6 Pride & Prejudice 3 0 austen
## 7 Pride & Prejudice 7 1 chapter
## 8 Pride & Prejudice 7 1 1
## 9 Pride & Prejudice 10 1 it
## 10 Pride & Prejudice 10 1 is
## # ... with 122,194 more rows
# define larger sections of text that span multiple lines and find the net sentiment in each of these sections of text
afinn <- pride_prejudice %>%
inner_join(get_sentiments("afinn")) %>%
group_by(index = linenumber %/% 80) %>%
summarise(sentiment = sum(value)) %>%
mutate(method = "AFINN")
## Joining, by = "word"
bing_and_nrc <- bind_rows(
pride_prejudice %>%
inner_join(get_sentiments("bing")) %>%
mutate(method = "Bing et al."),
pride_prejudice %>%
inner_join(get_sentiments("nrc") %>%
filter(sentiment %in% c("positive",
"negative"))
) %>%
mutate(method = "NRC")) %>%
count(method, index = linenumber %/% 80, sentiment) %>%
pivot_wider(names_from = sentiment,
values_from = n,
values_fill = 0) %>%
mutate(sentiment = positive - negative)
## Joining, by = "word"
## Joining, by = "word"
# Bind them together and visualize them
bind_rows(afinn,
bing_and_nrc) %>%
ggplot(aes(index, sentiment, fill = method)) +
geom_col(show.legend = FALSE) +
facet_wrap(~method, ncol = 1, scales = "free_y")
# how many positive and negative words are in these lexicons
get_sentiments("nrc") %>%
filter(sentiment %in% c("positive", "negative")) %>%
count(sentiment)
## # A tibble: 2 x 2
## sentiment n
## * <chr> <int>
## 1 negative 3324
## 2 positive 2312
get_sentiments("bing") %>%
count(sentiment)
## # A tibble: 2 x 2
## sentiment n
## * <chr> <int>
## 1 negative 4781
## 2 positive 2005
bing_word_counts <- tidy_books %>%
inner_join(get_sentiments("bing")) %>%
count(word, sentiment, sort = TRUE) %>%
ungroup()
## Joining, by = "word"
bing_word_counts
## # A tibble: 2,585 x 3
## word sentiment n
## <chr> <chr> <int>
## 1 miss negative 1855
## 2 well positive 1523
## 3 good positive 1380
## 4 great positive 981
## 5 like positive 725
## 6 better positive 639
## 7 enough positive 613
## 8 happy positive 534
## 9 love positive 495
## 10 pleasure positive 462
## # ... with 2,575 more rows
# This can be shown visually, and we can pipe straight into ggplot2
bing_word_counts %>%
group_by(sentiment) %>%
slice_max(n, n = 10) %>%
ungroup() %>%
mutate(word = reorder(word, n)) %>%
ggplot(aes(n, word, fill = sentiment)) +
geom_col(show.legend = FALSE) +
facet_wrap(~sentiment, scales = "free_y") +
labs(x = "Contribution to sentiment",
y = NULL)
# Anomaly for the word "miss"
custom_stop_words <- bind_rows(tibble(word = c("miss"),
lexicon = c("custom")),
stop_words)
custom_stop_words
## # A tibble: 1,150 x 2
## word lexicon
## <chr> <chr>
## 1 miss custom
## 2 a SMART
## 3 a's SMART
## 4 able SMART
## 5 about SMART
## 6 above SMART
## 7 according SMART
## 8 accordingly SMART
## 9 across SMART
## 10 actually SMART
## # ... with 1,140 more rows
tidy_books %>%
anti_join(stop_words) %>%
count(word) %>%
with(wordcloud(word, n, max.words = 100))
## Joining, by = "word"
# sentiment analysis to tag positive and negative words using an inner join, then find the most common positive and negative words
tidy_books %>%
inner_join(get_sentiments("bing")) %>%
count(word, sentiment, sort = TRUE) %>%
acast(word ~ sentiment, value.var = "n", fill = 0) %>%
comparison.cloud(colors = c("gray20", "gray80"),
max.words = 100)
## Joining, by = "word"
p_and_p_sentences <- tibble(text = prideprejudice) %>%
unnest_tokens(sentence, text, token = "sentences")
p_and_p_sentences$sentence[2]
## [1] "by jane austen"
austen_chapters <- austen_books() %>%
group_by(book) %>%
unnest_tokens(chapter, text, token = "regex",
pattern = "Chapter|CHAPTER [\\dIVXLC]") %>%
ungroup()
austen_chapters %>%
group_by(book) %>%
summarise(chapters = n())
## # A tibble: 6 x 2
## book chapters
## * <fct> <int>
## 1 Sense & Sensibility 51
## 2 Pride & Prejudice 62
## 3 Mansfield Park 49
## 4 Emma 56
## 5 Northanger Abbey 32
## 6 Persuasion 25
bingnegative <- get_sentiments("bing") %>%
filter(sentiment == "negative")
wordcounts <- tidy_books %>%
group_by(book, chapter) %>%
summarize(words = n())
## `summarise()` has grouped output by 'book'. You can override using the `.groups` argument.
tidy_books %>%
semi_join(bingnegative) %>%
group_by(book, chapter) %>%
summarize(negativewords = n()) %>%
left_join(wordcounts, by = c("book", "chapter")) %>%
mutate(ratio = negativewords/words) %>%
filter(chapter != 0) %>%
slice_max(ratio, n = 1) %>%
ungroup()
## Joining, by = "word"
## `summarise()` has grouped output by 'book'. You can override using the `.groups` argument.
## # A tibble: 6 x 5
## book chapter negativewords words ratio
## <fct> <int> <int> <int> <dbl>
## 1 Sense & Sensibility 43 161 3405 0.0473
## 2 Pride & Prejudice 34 111 2104 0.0528
## 3 Mansfield Park 46 173 3685 0.0469
## 4 Emma 15 151 3340 0.0452
## 5 Northanger Abbey 21 149 2982 0.0500
## 6 Persuasion 4 62 1807 0.0343
I will analyze text “My Bondage and My Freedom” by Frederick Douglass. I will use the gutenbergr library to search and download it.
bondage_count <- gutenberg_download(202)
## Determining mirror for Project Gutenberg from http://www.gutenberg.org/robot/harvest
## Using mirror http://aleph.gutenberg.org
bondage_count
## # A tibble: 12,208 x 2
## gutenberg_id text
## <int> <chr>
## 1 202 "MY BONDAGE and MY FREEDOM"
## 2 202 ""
## 3 202 "By Frederick Douglass"
## 4 202 ""
## 5 202 ""
## 6 202 "By a principle essential to Christianity, a PERSON is eternall~
## 7 202 "differenced from a THING; so that the idea of a HUMAN BEING, n~
## 8 202 "excludes the idea of PROPERTY IN THAT BEING."
## 9 202 "--COLERIDGE"
## 10 202 ""
## # ... with 12,198 more rows
#removing the first 763 rows of text which are table of contents
bondage_count <- bondage_count[c(763:nrow(bondage_count)),]
#using unnest_tokens to have each line be broken into indidual rows.
bondage <- bondage_count %>% unnest_tokens(word, text)
bondage
## # A tibble: 129,472 x 2
## gutenberg_id word
## <int> <chr>
## 1 202 chapter
## 2 202 i
## 3 202 _childhood_
## 4 202 place
## 5 202 of
## 6 202 birth
## 7 202 character
## 8 202 of
## 9 202 the
## 10 202 district
## # ... with 129,462 more rows
bondage_index <- bondage_count %>%
filter(text != "") %>%
mutate(linenumber = row_number(),
chapter = cumsum(str_detect(text, regex("(?<=Chapter )([\\dII]{1,3})", ignore_case = TRUE))))
bondage_index
## # A tibble: 10,624 x 4
## gutenberg_id text linenumber chapter
## <int> <chr> <int> <int>
## 1 202 "CHAPTER I. _Childhood_" 1 1
## 2 202 "PLACE OF BIRTH--CHARACTER OF THE DISTRICT--~ 2 1
## 3 202 "NAME--CHOPTANK RIVER--TIME OF BIRTH--GENEAL~ 3 1
## 4 202 "COUNTING TIME--NAMES OF GRANDPARENTS--THEIR~ 4 1
## 5 202 "ESPECIALLY ESTEEMED--\"BORN TO GOOD LUCK\"-~ 5 1
## 6 202 "POTATOES--SUPERSTITION--THE LOG CABIN--ITS ~ 6 1
## 7 202 "CHILDREN--MY AUNTS--THEIR NAMES--FIRST KNOW~ 7 1
## 8 202 "MASTER--GRIEFS AND JOYS OF CHILDHOOD--COMPA~ 8 1
## 9 202 "SLAVE-BOY AND THE SON OF A SLAVEHOLDER." 9 1
## 10 202 "In Talbot county, Eastern Shore, Maryland, ~ 10 1
## # ... with 10,614 more rows
bondage %>%
inner_join(get_sentiments("bing")) %>%
filter(sentiment == "positive") %>%
count(word, sentiment, sort = TRUE) %>%
top_n(10) %>%
mutate(word = reorder(word, desc(n))) %>%
ggplot() +
aes(x = word, y = n) +
labs(title = "Most Frequent Positive Words") +
ylab("Count") +
xlab("Word") +
geom_col() +
geom_text(aes(label = n, vjust = -.5)) +
theme(
panel.background = element_rect(fill = "white", color = NA),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
plot.title = element_text(hjust = 0.5)
)
## Joining, by = "word"
## Selecting by n
bondage %>%
inner_join(get_sentiments("bing")) %>%
filter(sentiment == "negative") %>%
count(word, sentiment, sort = TRUE) %>%
top_n(10) %>%
mutate(word = reorder(word, desc(n))) %>%
ggplot() +
aes(x = word, y = n) +
labs(title = "Most Frequent Negative Words") +
ylab("Count") +
xlab("Word") +
geom_col() +
geom_text(aes(label = n, vjust = -.5)) +
theme(
panel.background = element_rect(fill = "white", color = NA),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
plot.title = element_text(hjust = 0.5)
)
## Joining, by = "word"
## Selecting by n
Here, I will use loughran lexicon instead of one of the lexicons used in the sample code.
lghrn <- get_sentiments("loughran")
unique(lghrn$sentiment)
## [1] "negative" "positive" "uncertainty" "litigious" "constraining"
## [6] "superfluous"
#let’s explore the lexicon to see what types of words are litigious and constraining.
bondage_index %>%
unnest_tokens(word, text) %>%
inner_join(get_sentiments("loughran")) %>%
filter(sentiment %in% c("litigious", "constraining")) %>%
count(word, sentiment, sort = TRUE) %>%
group_by(sentiment) %>%
top_n(10) %>%
ggplot() +
aes(x = reorder(word,desc(n)), y = n) +
geom_col() +
facet_grid(~sentiment, scales = "free_x") +
geom_text(aes(label = n, vjust = -.5)) +
labs(title = "Words Associated with Litigious and Constraining") +
ylab("Count") +
xlab("Word") +
theme(
panel.background = element_rect(fill = "white", color = NA),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
plot.title = element_text(hjust = 0.5)
)
## Joining, by = "word"
## Selecting by n