Using do loops in R to create new variables

Question

I\'m a long time SAS programmer looking to make the jump to R. I know R isn\'t all that great for variable re-coding but is there a way to do this with do loops.

If

Answer 1

The R way would be to use lists.

> a_1 = 1
> a_2 = 2
> a_3 = 3
> a_4 = 4
> a_5 = 5

> b_1 = 1
> b_2 = 2
> b_3 = 3
> b_4 = 4
> b_5 = 5

> a.list <- ls(patter='a_*')
> a.list
[1] "a_1" "a_2" "a_3" "a_4" "a_5"

and define blist as well.

if(length(a.list)==length(b.list)){
   c.list <- lapply(1:length(a.list), function(x) eval(parse(text=a.list[x])) + eval(parse(text=b.list[x])))

   c.list.names <- paste('c', 1:length(a.list), sep='_')

   lapply(1:length(c.list), function(x) assign(c.list.names[x], c.list[x], envir=.GlobalEnv)) 
}

I can't think of a way to do this without the eval(parse(yuk)) and assign unless you follow csgillespie's advice (which is the right way!)