[R] question on 'within' and 'parse' commands

Hi, Why can't I pass an expression to `within' by way of textual input to the 'parse' function? e.g., x - data.frame(a=1:5,b=LETTERS[1:5]) x a b 1 1 A 2 2 B 3 3 C 4 4 D 5 5 E within(x, parse(text=a-a*10; b-2:6)) a b 1 1 A 2 2 B 3 3 C 4 4 D 5 5 E within(x, parse(text=a-a*10;

Re: [R] question on 'within' and 'parse' commands

Hello, parse just parse the text into an expression. parse(text=a-a*10; b-2:6) expression(a-a*10, b-2:6) attr(,srcfile) text If you want to evaluate the expression, you need to call eval y - within(x, eval(parse(text=a-a*10; b-2:6))) y a b 1 10 2 2 20 3 3 30 4 4 40 5 5 50 6 Or you can