[R] create a correct list from Document Term Matrix

[David Winsemius]

> On May 6, 2017, at 8:14 AM, David Winsemius <dwinsemius at comcast.net> wrote:
> 
>> 
>> On May 6, 2017, at 7:47 AM, Elahe chalabi via R-help <r-help at r-project.org> wrote:
>> 
>> Hi all,
>> 
>> I have a text classification task which is classification of a Control group and Alzheimer group texts. I have generated DocumentTermMatrix for both groups and then created a list with one extra element showing the group name if it's Alzheimer or control group, for example for the Alzheimer group:
>> 
>> frequenciesAlzheimer=DocumentTermMatrix(corpus)
>> freqlistAlz=list(type="alzheimer",frequenciesAlzheimer)
>> 
>> List of 2
>> $ type: chr "alzheimer"
>> $        :List of 6    *
>> ..$ i      : int [1:8678] 1 1 1 1 1 1 1 1 1 1 ...
>> ..$ j      : int [1:8678] 1 2 3 4 5 6 7 8 9 10 ...
>> ..$ v      : num [1:8678] 1 1 1 1 1 2 1 1 2 1 ...
>> ..$ nrow    : int 255
>> ..$ ncol    : int 1091
>> ..$ dimnames:List of 2
>> .. ..$ Docs : chr [1:255] "1" "2" "3" "4" ...
>> .. ..$ Terms: chr [1:1091] "alright" "bad" "boy" "cookie" ...
>> ..- attr(*, "class")= chr [1:2] "DocumentTermMatrix" "simple_triplet_matrix"
>> ..- attr(*, "weighting")= chr [1:2] "term frequency" "tf"
>> 
>> and I have the same list for control group,now my question is why I don't get the name of my DTM as the second element of my list? in the line marked by *
>> I need to have
>> 
>> 
>> $frequenciesAlzheimer : List of 6
>> 
>> but there's no name, does anyone know how should I solve this?
> 
> Why don't you just assign a name to that list? Either of these should succeed:
> 
> 
> names(freqlistAlz)[2] <- frequenciesAlzheimer

Sigh. The dangers of untested code (due to no offered example.) My wetware interpreter now tells me that it probably should have been:

names(freqlistAlz)[2] <- "frequenciesAlzheimer"


> 
> freqlistAlz=list(type="alzheimer", 
>                   frequenciesAlzheimer =  frequenciesAlzheimer)
> 
> -- 
> David.
> 
> 
>> 
>> Thanks for any help!
>> Elahe
>> 
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> 
> David Winsemius
> Alameda, CA, USA
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

David Winsemius
Alameda, CA, USA