assigning a string to an object without double quotes

Question

I have a string that is built programmatically

 tot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10

that I need to wrap in two si

Answer 1

Generate data:

set.seed(101)
dat.test <- do.call(data.frame,replicate(6,sample(1:10, 50, replace=TRUE),
                                    simplify=FALSE))
names(dat.test) <- paste0("s1.item",1:6)

myList1 <- list(scale1.tot=paste0("s1.item",1:6),
                scale1.sub1=paste0("s1.item",1:3),
                scale1.sub2=paste0("s1.item",4:6))

I only made one item here, but you could apply across a set of these too, with another *apply call or a for loop ...

This works (although it gives warnings because the data are trivial)

fitList <- mapply(function(lhs,rhs) {
           mod <- paste(lhs,"=~",paste(rhs,collapse="+"))
           cfa(mod,data=dat.test)
       },
       names(myList),myList)

Answer 2

I think you are misunderstanding R string syntax. The string you described is:

# this is what I want
mod <- '
    tot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10
'

That is exactly the same as writing:

mod <- '\ntot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10\n'

or

mod <- "\ntot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10\n"

Therefore, for your problem I think it would be sufficient to run:

string <- "tot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10"
mod <- paste0("\n", string, "\n")

If you want to output your final model without the enclosing quotes, you can do:

cat(mod)
# 
# tot=~item1+item2+item3+item4+item5+item6+item7+item8+item9+item10