[R] from expand.grid to a list (lapply)

[Gerrit Eichner]

Hie Alaiso,

try to simply apply lapply() to your data frame. It should work w/o any 
further operation since data frames are lists (check with is.list()).

  Hth  --  Gerrit

On Wed, 25 Feb 2015, Alaios via R-help wrote:

> Hi all,I would like to use an expand.grid functionality that would give 
> me at the end a listso far my code looks like:
>  sigma_max_On_seq<-seq(0.05,100,length.out=10000)
> mean_max_On_seq<-seq(2,10000),length.out=10000)
> expandMeanSigmaOn<-expand.grid(mean_max_On_seq,mean_max_On_seq,sigma_max_On_seq,sigma_max_On_seq)
> that gives me at the end all the possible combinations as a data 
> frame.
> Browse[1]> str((expandMeanSigmaOn))
> 'data.frame':   XXX obs. of  4 variables:
>  $ Var1: num  1 11432 22864 34295 45727 ...
>  $ Var2: num  1 1 1 1 1 1 1 1 1 1 ...
>  $ Var3: num  0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ...
>  $ Var4: num  0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ...
>  - attr(*, "out.attrs")=List of 2
>   ..$ dim     : int  10 10 10 10
>   ..$ dimnames:List of 4
>   .. ..$ Var1: chr  "Var1=     1.00" "Var1= 11432.44" "Var1= 22863.89" "Var1= 34295.33" ...
>   .. ..$ Var2: chr  "Var2=     1.00" "Var2= 11432.44" "Var2= 22863.89" "Var2= 34295.33" ...
>   .. ..$ Var3: chr  "Var3=  0.05000" "Var3= 31.48065" "Var3= 62.91131" "Var3= 94.34196" ...
>   .. ..$ Var4: chr  "Var4=  0.05000" "Var4= 31.48065" "Var4= 62.91131" "Var4= 94.34196" ...
>
>  but I want to have a list that I would be able to use it as input into 
> a lapply function. The lapply should use then each list entry 
> independently giving as input variables only the current 
> $Var1,$Var2,$Var3,$Var4
>
> How I can convert in R the data.frame into a list?
> I would like to thank you in advance for your replyRegardsAlex