I have a unnest_tokens function that works in the code, but once I put it into a function I cannot get it to work. I don't understand why this happens when I put it inside a function.
data:
id words
1 why is this function not working
2 more text
3 help me
4 thank you
5 in advance
6 xx xx
The data is checked on stringsAsFactors == FALSE and if it's a Vector.
is.vector(data$words)
[1] TRUE
is.vector(data$id)
[1] TRUE
typeof(data$words)
[1] "character"
Here is the code outside of the function which gives the correct output:
df <- x %>%
unnest_tokens(word, words)%>%
group_by(id)
1 why
1 is
1 this
1 function
1 not
1 working
2 more
2 text
3 help
3 me
4 thank
4 you
5 in
5 advance
6 xx
6 xx
Once I put the code in a function I get an error.
tidy_x <- unnestDF(data, "words", "id")
unnestDF <- function(df, col, groupbyCol) {
x <- df %>%
unnest_tokens(word, df[col])%>%
group_by(df[groupbyCol])
return(x)
}
Error in check_input(x) : Input must be a character vector of any length or a list of character vectors, each of which has a length of 1.
Thank you in advance.
As we are using quoted arguments, one option would be to convert to symbol and then evaluate (!!) within unnest_tokens and instead of group_by use group_by_at which can take strings
unnestDF <- function(df, col, groupbyCol) {
df %>%
unnest_tokens(word, !! rlang::sym(col))%>%
group_by_at(groupbyCol)
}
unnestDF(data, "words", "id")
# A tibble: 16 x 2
# Groups: id [6]
# id word
# * <int> <chr>
# 1 1 why
# 2 1 is
# 3 1 this
# 4 1 function
# 5 1 not
# 6 1 working
# 7 2 more
# 8 2 text
# 9 3 help
#10 3 me
#11 4 thank
#12 4 you
#13 5 in
#14 5 advance
#15 6 xx
#16 6 xx