[R] Execute a function

[Bert Gunter]

Inline.

-- Bert

On Fri, Jul 20, 2012 at 6:59 AM, Peter Ehlers <ehlers at ucalgary.ca> wrote:
> On 2012-07-20 04:05, carla moreira wrote:
>>
>>
>> Hi,
>>
>> I would like to evaluate a function, with 3 arguments, for instance,
>>
>> myfunc<-function(a,b,c) { sqrt(a)-exp(b)+4*c
>>                                                  }
>>
>> How to execute  myfunc(x,y,z), for all x, all y and all z, where x,y,z are
>> vectors?
>
>
> Is this what you have in mind:
>
>   myfunc <- function(a, b, c){ sqrt(a)-exp(b)+4*c }
>   myfunc2 <- function(x){
>     a <- x[1]
>     b <- x[2]
>     c <- x[3]
>     myfunc(a, b, c)
>   }
>
>   x <- c(1, 4, 9)
>   y <- 1:2
>   z <- c(10, -10, 2, 20)
>   d <- expand.grid(x, y, z)

Peter, what's wrong with
with(d,myfunc(x,y,z))    ??

I realize this depends on the function be vectorizable, but isn't that
the point? It could be orders of magnitude faster than looping via
apply.

-- Bert

>   d$value <- apply(d, 1, myfunc2)
>
> ?
>
> Peter Ehlers
>
>>
>> Thank you very much in advance
>>
>>
>>
>> --
>> View this message in context:
>> http://r.789695.n4.nabble.com/Execute-a-function-tp4637182.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
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>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> ______________________________________________
> R-help at r-project.org 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.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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