[R] lists and rownames

[Sarah Goslee]

They aren't being stored, they are being generated on the fly. You can
create the same names using make.names()

example.names <- c("con1-1-masked-bottom-green.tsv",
"con1-1-masked-bottom-red.tsv", "con1-1-masked-top-green.tsv",
"con1-1-masked-top-red.tsv")

example.list <- strsplit(example.names, "-")

as.data.frame(example.list)

> make.names(example.list)
[1] "c..con1....1....masked....bottom....green.tsv.."
"c..con1....1....masked....bottom....red.tsv.."
[3] "c..con1....1....masked....top....green.tsv.."
"c..con1....1....masked....top....red.tsv.."


But you'll probably get a more usable result if you set names
explicitly, for instance:

names(example.list) <- example.names
as.data.frame(example.list)

Note that the characters that are not legal in column names are
changed for you. You can disable that behavior with check.names=FALSE
if you use data.frame() rather than as.data.frame().

Sarah



On Mon, Apr 18, 2016 at 4:21 PM, Ed Siefker <ebs15242 at gmail.com> wrote:
> I'm doing some string manipulation on a vector of file names, and noticed
> something curious.  When I strsplit the vector, I get a list of
> character vectors.
> The list is numbered, as lists are.  When I cast that list as a data
> frame with 'as.data.frame()', the resulting columns have names derived
> from the original filenames.
>
> Example code is below.  My question is, where are these names stored
> in the list?  Are there methods that can access this from the list?
> Is there a way to preserve them verbatim?  Thanks
> -Ed
>
>> example.names
> [1] "con1-1-masked-bottom-green.tsv" "con1-1-masked-bottom-red.tsv"
> [3] "con1-1-masked-top-green.tsv"    "con1-1-masked-top-red.tsv"
>> example.list <- strsplit(example.names, "-")
>> example.list
> [[1]]
> [1] "con1"      "1"         "masked"    "bottom"    "green.tsv"
>
> [[2]]
> [1] "con1"    "1"       "masked"  "bottom"  "red.tsv"
>
> [[3]]
> [1] "con1"      "1"         "masked"    "top"       "green.tsv"
>
> [[4]]
> [1] "con1"    "1"       "masked"  "top"     "red.tsv"
>
>> example.df <- as.data.frame(example.list)
>> example.df
>   c..con1....1....masked....bottom....green.tsv..
> 1                                            con1
> 2                                               1
> 3                                          masked
> 4                                          bottom
> 5                                       green.tsv
>   c..con1....1....masked....bottom....red.tsv..
> 1                                          con1
> 2                                             1
> 3                                        masked
> 4                                        bottom
> 5                                       red.tsv
>   c..con1....1....masked....top....green.tsv..
> 1                                         con1
> 2                                            1
> 3                                       masked
> 4                                          top
> 5                                    green.tsv
>   c..con1....1....masked....top....red.tsv..
> 1                                       con1
> 2                                          1
> 3                                     masked
> 4                                        top
> 5                                    red.tsv
>