# [R] list of lists question

Karla Sartor ksartor at montana.edu
Wed Nov 24 03:43:30 CET 2004

```Hello all,
As a general programming question I can't seem to figure out how to make
a list of lists in R.
As matrices won't work as they have to be rectangular.

I am sure that there is an easy solution but...

the specific situation is this:
- I have created a Tukey confidence interval table and have listed the
means that are not significantly different
- then using these not significantly different pairs I have created the
groups of means that are not significantly different from each other
the issue then is that many of these lists are subsets of other lists
and I need to check for this.

Below is a little program is illustrate the issue

> a=c(1,1,1,1,1)                  # generate the first list
> b=c(2,2,2)                        # generate a second list
> c=c(a,b)                           #combine them
> cat(c, "\n")                        # and print
1 1 1 1 1 2 2 2                   #  this is 1-D!!! ahh
> d=list(a,b)                        # make a list of a and b
> d                                       #  and print
[[1]]                                      #this is exactly what I want,
but continue
[1] 1 1 1 1 1

[[2]]
[1] 2 2 2

> e=list(d,a)                           # now on the next iteration I
need to add another list to this list of lists
> e                                         # and print
[[1]]                                       # ahh all hell has broken
loose and this is not what I want
[[1]][[1]]                               #  desired result below
[1] 1 1 1 1 1

[[1]][[2]]
[1] 2 2 2

[[2]]
[1] 1 1 1 1 1

-------------
desired result

#wrong code but this is what I want to happen
a=c(1,1,1,1,1,1,1)
for(i in 1:5) {
a=list(a,1:5)
}

output I want is (something like)
[1] 1 1 1 1 1 1 1
[2] 1 2 3 4 5
[3] 1 2 3 4 5
[4] 1 2 3 4 5
[5] 1 2 3 4 5
[6] 1 2 3 4 5

so then I could call cat(a[1]) and get 1 1 1 1 1 1 1 1 and cat(a[2]) and
get 1 2 3 4 5

Anyone know the answer (hopefully simple)

Cheers,

Karla Sartor

----------------------------------------------------------
Karla Sartor
Montana State University - LRES
ksartor at montana.edu

```