[R] Recursive looping of a list in R

[Gerrit Eichner]

Hi Evans,

not many people (incl. me) are going to guess the building law for your 
recursive structure from the -- in fact at first sight not so clear -- 
picture, but I have some comments inline below.

  Hth  --  Gerrit

> I am trying to creat a list from a loop such that once you loop the 
> value obtained is appended onto the list, then you loop through that 
> value to give the next elemet of the list and the system continues 
> recusively. To be clear I am creating a list to contain elements of the 
> following tree probabilities; 
> <http://r.789695.n4.nabble.com/file/n4710898/help.png> .
> The elements of the diagram should be presented in a list such that each 
> level of the tree represents elements in the list (only the coefficients 
> are of interest). I have this code to start with


If you use a while-loop without a termination criterion and, e.g., a call 
to break, in its body it would run forever (if the code in its body were 
correct). Start coding with a (finite) for-loop. (Or even better start 
setting j and i "by hand" and let your code be evaluated step by step.)

> j <- 0
>
> while(j >= 0){
>
>  j <- j+1


Here you create in each loop the same starting list (which I guess is not 
what you want/should):

>  occlist <- list(1)


So, as a consequence an error occurs for j >= 2 in the following for-loop, 
because occlist has always only 1 component:

>  for(i in occlist[[j]]){
>
>    occ_cell <- seq(i, i+1, by = 1)


The following two lines of code compensate each other, so seem to be 
superfluous:

>    occllist <- list(occ_cell)
>
>    occunlist <- as.vector(unlist(occllist, recursive = TRUE))



>    occlist[[j]] <- occunlist
>
>    print(occlist)
>
>  }
> }
>
> Any assistance will be highly appreciated. Thanks.
>
>
>
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