R help - Apr 2005 - Beginner in R

hello ( and sorry for my poor english ... )

I'm a newbie on R software and I need to obtain this kind of system :

a structure, like a liste :

my_struct <- list()
my_struct$a <- a_value
my_struct$b <- another_value
my_struct$c <- one_more_value

and a function with two args : the first is a instance of the structure, 
and the second is any component of the structure (here $a, $b or $c) and 
the function will do some transformations on this component :

my_func <- function(a_struct, a_comp)
{
    a_comp <- transformationFunct(a_comp)
   
    a_result <- someComputation(a_struct)

    return(a_result)      
}

In reallity, the structure have lot of components (+/- 40) who are input 
parameters for a time discret model and this function is to do selective 
sensitivity analysis.

Thanks in advance for this information and thanks for doing a open high 
quality software.

Norbert

Norbert Billet <norbert.billet at mpl.ird.fr> writes:
> hello ( and sorry for my poor english ... )
> 
> I'm a newbie on R software and I need to obtain this kind of system :
> 
> a structure, like a liste :
> 
> my_struct <- list()
> my_struct$a <- a_value
> my_struct$b <- another_value
> my_struct$c <- one_more_value
> 
> and a function with two args : the first is a instance of the
> structure, and the second is any component of the structure (here $a,
> $b or $c) and the function will do some transformations on this
> component :
> 
> my_func <- function(a_struct, a_comp)
> {
>     a_comp <- transformationFunct(a_comp)
>      a_result <- someComputation(a_struct)
> 
>     return(a_result)      }
If I catch your drift, you're looking for something like

my_func <- function(a_struct, a_name) {
    a_struct[[a_name]]  <- transformationFunct(a_struct[[a_name]])
    someComputation(a_struct)
}


my_func(my_struct, "b")

or maybe even a loop over all components with

lapply(names(my_struct), my_func, a_struct=my_struct)


> In reallity, the structure have lot of components (+/- 40) who are
> input parameters for a time discret model and this function is to do
> selective sensitivity analysis.
> 
> Thanks in advance for this information and thanks for doing a open
> high quality software.
> 
> Norbert

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  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
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