Automating the Replacement of a Word in a Script

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In this article, we will explore how to automate the replacement of a word in a script using R and its corresponding libraries. The goal is to create a function that can replace multiple words with ease.

Background

Creating proportion graphs for a list of words can be an involved process. Manually copying and pasting each new word into the appropriate place could become tedious, especially when dealing with long lists. This article aims to provide an easy-to-follow guide on how to create such a function using R.

Understanding the Script

The provided script uses the ggplot2 library for data visualization and the dfm package for topic modeling. It consists of two main parts:

1. The creation of a data frame with word frequencies.
2. The plotting of the graph.

However, replacing the word “research” in this script would require manual editing each time. We can automate this process using a function.

Creating the Function

The f1 function takes two parameters: the corpus object (corpus_obj) and the word to be replaced (word). The function first converts the word to uppercase, as specified in the original script.

f1 <- function(corpus_obj, word) {
    word_new <- sub("^(.)(.*)", "\\1\\L\\2", toupper(word), perl = TRUE)
    dfm_research <-  dfm(corpus_obj) %>%
      dfm_group(groups = "Year") %>%
      dfm_weight(scheme = "prop") %>%
      dfm_select(pattern = word) 
    colnames(dfm_research)[1] <- word
    dfm_research2 <- convert(dfm_research, to = "data.frame")
    dfm_research2$doc_id <- as.numeric(dfm_research2$doc_id)
    # plot
    dfm_research3 <- melt(dfm_research2, id.vars = "doc_id")
    options(scipen = 999)
    ggplot(data = dfm_research3, aes(x = doc_id, y = value))+
      geom_line(aes(x = doc_id, y = value),colour = "red") +
      scale_x_continuous(limits = c(1999, 2019), breaks = c(seq(1999, 2019, 1))) +
      scale_y_continuous(limits = c(0, 0.005), breaks = c(seq(0, 0.005, 0.001))) +
       labs(title = paste0(word_new, " by proportions")) +
       theme(axis.text.x = element_text(angle = 45, hjust = 1)) 
}

Using the Function

To use this function, we first need to create a corpus object (corpus_toks). We can do this using various methods available in the tm package.

# Load necessary libraries
library(tm)
library(ggplot2)

# Create a document collection
corpus_obj <- Corpus(VCorpus(DocType("txt"), ReadDir("data")))

# Convert to lower case and remove punctuation
corpus_obj <- content_transformer(function(x) x[[1]] %>%
  tolower() %>%
  gsub("\\p{Punct}", "", .))

# Remove stop words
stop_words <- stopwords("english")
corpus_obj <- removeWords(corpus_obj, stop_words)

# Create the corpus object
corpus_toks <- Corpus(documentTermMatrix(corpus_obj))

Next, we can call the f1 function using this corpus object and any desired word.

word_vector <- c('research', 'anotherword', ....)
lapply(word_vector, function(x) f1(corpus_toks, x))

Conclusion

Replacing words in a script can become tedious when dealing with long lists. The creation of the f1 function provides an easy way to automate this process using R.

By following these steps, we have demonstrated how to create and use such a function for replacing multiple words in a script.

Additional Resources

• ggplot2 library documentation
• dfm package documentation
• tm package documentation

Last modified on 2025-02-14