From: jim holtman <jholtman_at_gmail.com>

Date: Fri 20 Oct 2006 - 14:31:54 GMT

Date: Fri 20 Oct 2006 - 14:31:54 GMT

will this work for you?

*> t0 <- function(x) {1}
**> t1 <- function(x) {x}
**> t2 <- function(x) {x^2}
**> t3 <- function(x) {x^3}
**>
**> t.l <- list(t0,t1,t2,t3)
**> t.l
*

[[1]]

function(x) {1}

[[2]]

function(x) {x}

[[3]]

function(x) {x^2}

[[4]]

function(x) {x^3}

*> arg.val <- 4 # evaluate for 4
*

*> sum(unlist(lapply(t.l, function(x)x(arg.val))))
*

[1] 85

On 10/20/06, James Foadi <jf117@york.ac.uk> wrote:

> Dear all,

*> I have looked for an answer for a couple of days, but can't come with any
**> solution.
**>
**> I have a set of functions, say:
**>
**> > t0 <- function(x) {1}
**> > t1 <- function(x) {x}
**> > t2 <- function(x) {x^2}
**> > t3 <- function(x) {x^3}
**>
**> I would like to find a way to add up the previous 4 functions and obtain a new
**> function:
**>
**> > rrr <- function(x) {1+x+x^2+x^3}
**>
**> without, actually, having to write it in the previous form (I could have cases
**> with hundreds of functions). I thought that perhaps I could first define a
**> list of functions:
**>
**> > ttt <- list(t0,t1,t2,t3)
**>
**> and then I could use something like "sum", to add up all the elements of the
**> list and obtain another function. I've tried:
**>
**> > rrr <- function(x) {sum(ttt)}
**>
**> but it does not work.
**>
**> Any help with this is greatly appreciated.
**>
**> Cheers,
**>
**> james
**> --
**> Dr James Foadi
**> Department of Physics
**> University of York
**> York YO10 5DD
**>
**> email: jf117@york.ac.uk
**> web page: http://www-users.york.ac.uk/~jf117
**> Tel: 0044 1904 434622
**> Mobile: 0044 7740 678548
**>
**> ______________________________________________
**> R-help@stat.math.ethz.ch mailing list
**> https://stat.ethz.ch/mailman/listinfo/r-help
**> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
**> and provide commented, minimal, self-contained, reproducible code.
**>
*

-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.Received on Sat Oct 21 12:31:26 2006

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