Re: [R] help in substitute function

2007-10-05 Thread Alberto Monteiro
Ronaldo Reis Junior asked: > > I try to use a substitute function to generalise a equation. > > I have this: > > expression(1+2*pred+3*lat) > > (...) My expected result is: > > expression(1 + 2 * x1 + 3 * x2) > Check message by Thomas Lumley on 2007-03-27 (command... RSiteSearch("Replacement

Re: [R] help in substitute function

2007-10-05 Thread Gabor Grothendieck
On 10/5/07, Gabor Grothendieck <[EMAIL PROTECTED]> wrote: > Given this: > > x1 <- "pred" > x2 <- "lat" > e <- expression(1+2*pred+3*lat) > > Try this: > > L <- list(as.name("x1"), as.name("x2")) > names(L) <- c(x1, x2) > do.call(substitute, list(e, L)) # e & L are evaluated first > > or perhaps: >

Re: [R] help in substitute function

2007-10-05 Thread Gabor Grothendieck
Given this: x1 <- "pred" x2 <- "lat" e <- expression(1+2*pred+3*lat) Try this: L <- list(as.name("x1"), as.name("x2")) names(L) <- c(x1, x2) do.call(substitute, list(e, L)) # e & L are evaluated first or perhaps: f <- e f <- sub("pred", "x1", f) # also converts to character f <- sub("lat", "x2

Re: [R] help in substitute function

2007-10-05 Thread Henrique Dallazuanna
Hi, try this(Not tested): substitute(expression(1+2*pred+3*lat),list(pred=as.name(x1),lat=as.name(x2))) On 05/10/2007, Ronaldo Reis Junior <[EMAIL PROTECTED]> wrote: > > Hi, > > I try to use a substitute function to generalise a equation. > > I have this: > > expression(1+2*pred+3*lat) > > I

[R] help in substitute function

2007-10-05 Thread Ronaldo Reis Junior
Hi, I try to use a substitute function to generalise a equation. I have this: expression(1+2*pred+3*lat) I need to define the equation in function of x1 and x2 variables. Also I try to define who is x1 and x2. I try this: X1 <- "pred" X2 <- "lat" Now I need substitute pred and lat in equatio