[R] Why do I have a column called row.names?

[Rui Barradas]

Hello,

It must be something else. Mandatory row names have nothing to do with a 
column header.
I've put the data example in a tab separated file and the strange 
behavior was not reproduced.

 > read.delim("test.txt", row.names=NULL, fill=TRUE)
     start     stop           Symbol Insert.sequence Clone.End.Pair FISH
1  203048 67173930 ABC8-43024000D23    TI:993812543   TI:993834585   NA
2  255176 87869359 ABC8-43034700N15    TI:995224581   TI:995237913   NA
3 1022033  1060472    ABC27-1253C21   TI:2094436044  TI:2094696079   NA
4 1022033  1061172     ABC23-1388A1   TI:2120730727  TI:2121592459   NA


With read.table, I tried with and without header=TRUE. No "success".

Rui Barradas

Em 04-06-2012 19:30, Bert Gunter escreveu:
> Actually, I think it's ?data.frame that he should read.
>
> The salient points are that:
> 1. All data frames must have unique row names. If not provided, they
> are produced. Row numbers **are** row names.
>
> 2. The return value of read methods are data frames.
>
> -- Bert
>
> On Mon, Jun 4, 2012 at 11:05 AM, David L Carlson<dcarlson at tamu.edu>  wrote:
>> Try help("read.delim") - always a good strategy before using a function for
>> the first time:
>>
>> In it, you will find: "Using row.names = NULL forces row numbering. Missing
>> or NULL row.names generate row names that are considered to be 'automatic'
>> (and not preserved by as.matrix)."
>>
>> ----------------------------------------------
>> David L Carlson
>> Associate Professor of Anthropology
>> Texas A&M University
>> College Station, TX 77843-4352
>>
>>
>>> -----Original Message-----
>>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
>>> project.org] On Behalf Of Ed Siefker
>>> Sent: Monday, June 04, 2012 12:47 PM
>>> To: r-help at r-project.org
>>> Subject: [R] Why do I have a column called row.names?
>>>
>>> I'm trying to read in a tab separated table with read.delim().
>>> I don't particularly care what the row names are.
>>> My data file looks like this:
>>>
>>>
>>> start   stop    Symbol  Insert sequence Clone End Pair  FISH
>>> 203048  67173930        ABC8-43024000D23                TI:993812543
>>>   TI:993834585
>>> 255176  87869359        ABC8-43034700N15                TI:995224581
>>>   TI:995237913
>>> 1022033 1060472 ABC27-1253C21           TI:2094436044   TI:2094696079
>>> 1022033 1061172 ABC23-1388A1            TI:2120730727   TI:2121592459
>>>
>>>
>>>
>>> I have to do something with row.names because my first column has
>>> duplicate entries.  So I read in the file like this:
>>>
>>>> BACS<-read.delim("testdata.txt", row.names=NULL, fill=TRUE)
>>>> head(BACS)
>>>    row.names    start             stop Symbol Insert.sequence
>>> Clone.End.Pair
>>> 1    203048 67173930 ABC8-43024000D23     NA    TI:993812543
>>> TI:993834585
>>> 2    255176 87869359 ABC8-43034700N15     NA    TI:995224581
>>> TI:995237913
>>> 3   1022033  1060472    ABC27-1253C21     NA   TI:2094436044
>>> TI:2094696079
>>> 4   1022033  1061172     ABC23-1388A1     NA   TI:2120730727
>>> TI:2121592459
>>>    FISH
>>> 1   NA
>>> 2   NA
>>> 3   NA
>>> 4   NA
>>>
>>>
>>> Why is there a column named "row.names"?  I've tried a few different
>>> ways of invoking this, but I always get the first column named
>>> row.names,
>>> and the rest of the columns shifted by one.
>>>
>>> Obviously I could fix this by using row.names<-, but I'd like to
>>> understand
>>> why this happens.  Any insight?
>>>
>>> ______________________________________________
>>> 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.
>> ______________________________________________
>> 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.
>
>