CODEWITHSUNDEEP
rstring
Eisen
Eisen

Reputation: 1897

Converting R formula to string and then manipulating it

exposure <- 'B'
outcome <- 'A'

I have a formula that looks like this in R

form <- formula(A ~ B + C + D)

I want to convert it to a string like this where I remove the exposure and the outcome

C + D

How can i do this in R?

Upvotes: 0

Views: 43

Answers (2)

akrun
akrun

Reputation: 887901

Perhaps this helps

reformulate(setdiff(all.vars(form), c(exposure, outcome)))
~C + D

Upvotes: 1

Quentin
Quentin

Reputation: 360

form_str <- as.character(form)
[1] "~"         "A"         "B + C + D"
variables <- strsplit(form_str[3], " + ", fixed = TRUE)[[1]]
[1] "B" "C" "D"
paste(setdiff(variables, exposure), collapse = " + ")
"C + D"

Upvotes: 0

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