[R] Execute a function

[Peter Ehlers]

Bert,

The only thing wrong is that I'm still 75% asleep! Yikes!!
Thanks for the heads-up.

Carla: See Bert's solution.

Peter Ehlers

On 2012-07-20 07:10, Bert Gunter wrote:
> 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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>>>
>>
>> ______________________________________________
>> 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.
>
>
>