Passing multiple arguments as a list in R

Question

I wish to pass a list of arguments as a vector to another command in R. I do not want to repeat the same set of arguments every time.

This is the code that I have to run 6 times for each $full_text column of data frames ranging t1 to t6.

    library(quanteda)

t1t <- tokens(t1$full_text, what = 'word', remove_numbers = TRUE,
                 remove_punct = TRUE,
                 remove_symbols = TRUE,
                 remove_separators = TRUE,
                 remove_twitter = TRUE,
                 remove_hyphens = TRUE,
                 remove_url = TRUE)
t1t <- tokens_tolower(t1t)
t1t <- tokens_select(t1t, stopwords(), selection = "remove")
t1t <- unlist(t1t)
t1t <- unique(t1t)
t1t <- as.data.frame(t1t)
t1t <- as.data.frame.matrix(t1t)

Is there a way to pass a one-time argument.

Answer 1

As mentioned in the error message tokens expect character vector, corpus or tokens as input. You are passing a dataframe to it. Pass the respective column of text to it instead.

Also tokens can process vectors so you can pass multiple columns together as one vector.

library(quanteda)

tokens(c(t1$colname, t2$colname, t3$colname), what = "word", remove_numbers = TRUE, 
  remove_punct = TRUE, remove_symbols = TRUE, remove_separators = TRUE, 
  remove_twitter = TRUE, remove_hyphens  =TRUE, remove_url = TRUE)

Based on the update and taking an example from the help page of ?tokens

t1 <- data.frame(full_text = "#textanalysis is MY <3 4U @myhandle gr8 #stuff :-)", 
              stringsAsFactors = FALSE)
t2 <- data.frame(full_text = c("This is $10 in 999 different ways,\n up and down; 
    left and right!", "@kenbenoit working: on #quanteda 2day\t4ever, 
    http://textasdata.com?page=123."), stringsAsFactors = FALSE)

We can create a function to apply it to all dataframes

 complete_function <- function(x) {
   t1t <- tokens(x, what = 'word', remove_numbers = TRUE,
                  remove_punct = TRUE,
                  remove_symbols = TRUE,
                  remove_separators = TRUE,
                  remove_twitter = TRUE,
                  remove_hyphens = TRUE,
                  remove_url = TRUE)
   t1t <- tokens_tolower(t1t)
   t1t <- tokens_select(t1t, stopwords(), selection = "remove")
   t1t <- unlist(t1t)
   t1t <- unique(t1t)
   t1t <- as.data.frame(t1t)
   t1t <- as.data.frame.matrix(t1t)
}

Then use mget to get dataframes t1, t2, t3 etc and apply the function to "full_text" column of each dataframe.

lapply(mget(ls(pattern = "^t\\d+")), function(x) complete_function(x$full_text))

#$t1
#           t1t
#1 textanalysis
#2           4u
#3     myhandle
#4          gr8
#5        stuff

#$t2
#        t1t
#1 different
#2      ways
#3      left
#4     right
#5 kenbenoit
#6   working
#7  quanteda
#8      2day
#9     4ever