extractAIC.nls

On Sat, Jul 14, 2012 at 6:53 PM, Spencer Graves
<spencer.graves at prodsyse.com> wrote:

Hello:


       Does "extractAIC.nls" exist anywhere?  If no, is there some reason it
should not be used?


       I'm planning to add it to the fda package, but before I do, I felt a
need to ask if there is some reason I shouldn't or if there are caveats I
should include in the help page for it.

AIC in stats works on nls objects. It calls AIC.default which calls logLik.nls .

Thanks for the reply.  Unfortunately, it fails for me in the 
following modification of the first example in help('nls'):


 > require(graphics)
 > DNase1 <- subset(DNase, Run == 1)
 > fm1DNase1 <- nls(density ~ SSlogis(log(conc), Asym, xmid, scal), DNase1)
 > extractAIC(fm1DNase1)
Error in UseMethod("extractAIC") :
   no applicable method for 'extractAIC' applied to an object of class "nls"


       Other suggestions?
       Thanks,
       Spencer


  sessionInfo()
R version 2.15.1 (2012-06-22)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=English_United States.1252
[2] LC_CTYPE=English_United States.1252
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C
[5] LC_TIME=English_United States.1252

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods base