[R] Column renaming

[Peter Dalgaard]

Chip Barnaby wrote:
> Peter,
> My method seems to work, see below.  Is there some reason it might not
> work in general?  This is the tersest way I have found to rename, but
> it seems awkward, given that names( X) is repeated.
>
Nono, this technique works fine. It just wasn't what you wrote.... (look
closer!)

    -p
> Chip Barnaby
> --------------------------
>
> > head( airquality)
>   Ozone Solar.R Wind Temp Month Day
> 1    41     190  7.4   67     5   1
> 2    36     118  8.0   72     5   2
> 3    12     149 12.6   74     5   3
> 4    18     313 11.5   62     5   4
> 5    NA      NA 14.3   56     5   5
> 6    28      NA 14.9   66     5   6
> >
> > names( airquality)[names( airquality)=="Ozone"]<-"O3"
> > head( airquality)
>   O3 Solar.R Wind Temp Month Day
> 1 41     190  7.4   67     5   1
> 2 36     118  8.0   72     5   2
> 3 12     149 12.6   74     5   3
> 4 18     313 11.5   62     5   4
> 5 NA      NA 14.3   56     5   5
> 6 28      NA 14.9   66     5   6
> >
>
>
> At 11:19 AM 5/5/2008, Peter Dalgaard wrote:
>> Chip Barnaby wrote:
>> > Dear all,
>> >
>> > Is there a less cumbersome way to rename a column by name (as opposed
>> > to index) than --
>> >
>> > names( X)[ names[ X] == "bob"]<-"sue"
>> >
>> > ?
>> Not that I know of (notwithstanding that your code doesn't quite work as
>> it stands...). You might have thought that this would work, but it
>> obviously does not:
>>
>> > names(airquality["Ozone"]) <- "O3"
>> > head(airquality)
>>   Ozone Solar.R Wind Temp Month Day
>> 1    41     190  7.4   67     5   1
>> 2    36     118  8.0   72     5   2
>> 3    12     149 12.6   74     5   3
>> 4    18     313 11.5   62     5   4
>> 5    NA      NA 14.3   56     5   5
>> 6    28      NA 14.9   66     5   6
>>
>> (This is probably a design decision. In the same vein,
>>
>> airquality[6] <- data.frame(foo=1:153)
>>
>> will not change the name of column 6. It might be preferable if it did,
>> from the conceptual point of view, but it is one of those things where I
>> suspect that the world comes tumbling down if you try to change the
>> behaviour...)
>>
>> >
>> > A semi-related question: how does one get the index of a column by
>> > name, something along the lines of col.index( X, "sue") ?
>> >
>> match("sue", names(X))
>>
>> -- 
>>    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>>   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
>>  (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
>> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907
>
> ---------------------------------------------------------
> Chip Barnaby                   cbarnaby at wrightsoft.com
> Vice President of Research
> Wrightsoft Corp.               781-862-8719 x118 voice
> 131 Hartwell Ave               781-861-2058 fax
> Lexington, MA 02421         www.wrightsoft.com
> ---------------------------------------------------------
>
>


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907