[R] transposing a list of vectors

[Michael Friendly]

Thanks, Henrique
I *do* need to preserve the type of each list element (num or chr).
Thus, a first step might be

 > as.data.frame(testlist, stringsAsFactors=FALSE)
  shape cell.fill back.fill scale.max
1     0       red     white       100
2     0      blue     white       100
3     2     green     white       100
 > str(as.data.frame(testlist, stringsAsFactors=FALSE))
'data.frame':   3 obs. of  4 variables:
 $ shape    : num  0 0 2
 $ cell.fill: chr  "red" "blue" "green"
 $ back.fill: chr  "white" "white" "white"
 $ scale.max: num  100 100 100

I think, with this mod, your #2 gives me what I want:

 wanted.henrique <- lapply(split(x <- as.data.frame(testlist, 
stringsAsFactors=FALSE), 1:nrow(x)), as.list)
 > str(wanted.henrique)
List of 3
 $ 1:List of 4
  ..$ shape    : num 0
  ..$ cell.fill: chr "red"
  ..$ back.fill: chr "white"
  ..$ scale.max: num 100
 $ 2:List of 4
  ..$ shape    : num 0
  ..$ cell.fill: chr "blue"
  ..$ back.fill: chr "white"
  ..$ scale.max: num 100
 $ 3:List of 4
  ..$ shape    : num 2
  ..$ cell.fill: chr "green"
  ..$ back.fill: chr "white"
  ..$ scale.max: num 100


Henrique Dallazuanna wrote:
> Try this:
>
> #'1) But apply converts all to 'character'
> apply(as.data.frame(testlist), 1, as.list)
>
> #2)
> lapply(split(x <- as.data.frame(testlist), 1:nrow(x)), as.list)
>
> On Fri, Jan 15, 2010 at 11:09 AM, Michael Friendly <friendly at yorku.ca> wrote:
>   
>> I have a list of vectors, all forced to be the same length:
>>
>> testlist <- list(
>>   shape=c(0, 0, 2),
>>  cell.fill=c("red","blue","green"),
>>   back.fill=rep("white",3),
>>   scale.max=rep(100,3)
>>   )
>>     
>>> str(testlist)
>>>       
>> List of 4
>> $ shape    : num [1:3] 0 0 2
>> $ cell.fill: chr [1:3] "red" "blue" "green"
>> $ back.fill: chr [1:3] "white" "white" "white"
>> $ scale.max: num [1:3] 100 100 100
>>     
>> I need to 'transpose' them into a list of lists with named values like so:
>>
>> wanted <- list(
>>   list(shape=0, cell.fill="red", back.fill="white", scale.max=100),
>>   list(shape=0, cell.fill="blue", back.fill="white", scale.max=100),
>>   list(shape=2, cell.fill="green", back.fill="white", scale.max=100)
>>   )
>>     
>>> str(wanted)
>>>       
>> List of 3
>> $ :List of 4
>>  ..$ shape    : num 0
>>  ..$ cell.fill: chr "red"
>>  ..$ back.fill: chr "white"
>>  ..$ scale.max: num 3
>> $ :List of 4
>>  ..$ shape    : num 0
>>  ..$ cell.fill: chr "blue"
>>  ..$ back.fill: chr "white"
>>  ..$ scale.max: num 3
>> $ :List of 4
>>  ..$ shape    : num 2
>>  ..$ cell.fill: chr "green"
>>  ..$ back.fill: chr "white"
>>  ..$ scale.max: num 3
>>     
>> How can I do this in general?
>>
>> --
>> Michael Friendly     Email: friendly AT yorku DOT ca Professor, Psychology
>> Dept.
>> York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
>> 4700 Keele Street    http://www.math.yorku.ca/SCS/friendly.html
>> Toronto, ONT  M3J 1P3 CANADA
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>     
>
>
>
>   


-- 
Michael Friendly     Email: friendly AT yorku DOT ca 
Professor, Psychology Dept.
York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
4700 Keele Street    http://www.math.yorku.ca/SCS/friendly.html
Toronto, ONT  M3J 1P3 CANADA