Creating formula using very long strings in R

Question

I\'m in a situation where I have a vector full of column names for a really large data frame.

Let\'s assume: x = c(\"Name\", \"address\", \"Gender\", ......, \

Answer 1

You can reduce your data-set first

dat_small <- dat[,c("class",x)]

and then use

myformula <- as.formula("class ~ .")

The . means using all other (all but class) column.

Answer 2

The problem is that you have R keywords as column names. else is a keyword so you can't use it as a regular name.

A simplified example:

s <- c("x", "else", "z")
f <- paste("y~", paste(s, collapse="+"))
formula(f)
# Error in parse(text = x) : <text>:1:10: unexpected '+'
# 1: y~ x+else+
#              ^

The solution is to wrap your words in backticks "`" so that R will treat them as non-syntactic variable names.

f <- paste("y~", paste(sprintf("`%s`", s), collapse="+"))
formula(f)
# y ~ x + `else` + z

Answer 3

You may try reformulate

 reformulate(setdiff(x, 'class'), response='class')
 #class ~ Name + address + Gender

where 'x' is

  x <- c("Name", "address", "Gender", 'class')

If R keywords are in the 'x', you can do

   reformulate('.', response='class')
   #class ~ .