[R] Building a function

[Florent BATY]

  >On Thu, Aug 01, 2002 at 11:44:31AM +0200, Florent BATY wrote:
/>> Hello, /
/>> /
/>> Is it possible to build a function, a posteriori, by getting the names /
/>> of the arguments and the formula in a list or a vector ? When I use 
the /
/>> function as.function(), I don't know how to define explicitly the 
names /
/>> of my variables as formal arguments. /
/>> /
/>> Thanks /
/>> /
/>> /

 >Did you check with the example (in 'help(as.function)') ?

 >If yes, can you give more details ?

 >L.

I did actually but it haven't managed to solve my problem.
 From an "nls" object, I want to construct a function based on
    1) the formula:

    > summary(nlsED)$formula[[3]]
        (t < lag) * log10(x0) + (t > lag) * log10(x0 * exp(mu * (t -
        lag)))

    2) the arguments of this formula:
    > all.vars(summary(nlsED)$formula[[3]])
    [1] "t"   "lag" "x0"  "mu"

Next step should consist in declaring the names of these variables as 
the arguments of the function but I have an Error message:

    > 
as.function(c(alist(all.vars(summary(nlsED)$formula[[3]])),summary(nlsED)$formula[[3]]))
    Error in 
as.function.default(c(alist(all.vars(summary(nlsED)$formula[[3]])),  :
        invalid formal argument list for "function"

I managed to construct a function with no arguments in it:

    > as.function(c(summary(nlsED)$formula[[3]]))
    function ()
    (t < lag) * log10(x0) + (t > lag) * log10(x0 * exp(mu * (t -
        lag)))

But I can't define the arguments of this function.

Do you have any ideas ??

_______________________________________

Florent BATY
CNRS UMR 5558
Dynamique des Populations Bactériennes
Faculté de Médecine Lyon-Sud
69921 OULLINS, BP 12
FRANCE
tel : +33 (0)4 78 86 31 67
fax : +33 (0)4 78 86 31 49
_______________________________________



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