[R] Extracting "row.names"

Erik Iverson iverson at biostat.wisc.edu
Mon Jun 23 20:21:55 CEST 2008


row.names is a function that takes a data.frame as an argument.  So how 
about

 > row.names(data)

?

As an aside, 'data' is not the best choice for a variable name in R, 
since there is a function called 'data' that will get overridden if you 
do this ...

Patrick Richardson wrote:
> List,
> 
> I'm trying to extract the row names of a table I have read into R.
> 
>> data <- read.table("mesodata.txt", header=TRUE, row.names=1)
> 
> When I try to extract them using,
> 
>> names <- data$row.names
> 
> I get,
> 
>> names
> NULL
> 
> I've tried changing to a matrix, data frame, etc. and still get "NULL". 
> I've checked ?row.names as well as help on extracting part of an object,
> etc. and unless I'm missing something obvious (likely), I can't figure out
> how to extract them.
> 
> BACKGROUND
> I want to extract the row names (which are basically gene id's) as well as
> some other columns (which I can do successfully) and "cbind" them into
> another data frame (which I can also do successfully). I just can't get the
> row names extracted (Assigned) to an seperate object.
> 
> Any suggestions would be appreciated.
> 
> Many Thanks,
> 
> Patrick
> 
> 
> 
>> sessionInfo()
> R version 2.7.0 (2008-04-22) 
> i386-pc-mingw32 
> 
> locale:
> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> States.1252;LC_MONETARY=English_United
> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
> 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base 
>



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