[R] Replace / with - in date

[Christian Raschke]

Is there anything that speaks against just applying gsub to the factor 
levels if one would like to keep everything as factors (and not consider 
true Date classes or character vectors)? I.e:

 > x <- c("2000/01/01", "2001/02/01")
 > xd <- as.data.frame(x)
 > levels(xd$x) <- gsub("/", "-", levels(xd$x))

Christian


On 04/15/2010 01:08 PM, David Winsemius wrote:
>
> On Apr 15, 2010, at 1:51 PM, prem_R wrote:
>
>>
>> Hi,every one .I have searched the solutions in the forum  for 
>> replacing my
>> date value which is in a data frame  ,01/01/2000 to 01-01-2000 using 
>> replace
>> function but got the following warning message
>> x<-"2000/01/01"
>> xd<-as.data.frame(x)
>> xd$x<-replace(xd$x,xd$x=="/","-")
>
> The replace function does not work with factors, it works with 
> (complete) vectors, not substrings. It's also a real hassle to do such 
> operations on factors, so just use character vectors and try gsub 
> instead:
>
> > x<-"2000/01/01"
> > xd<-as.data.frame(x, stringsAsFactors=FALSE)
> > xd$x2<-gsub("/","-", xd$x)
> > xd
>            x         x2
> 1 2000/01/01 2000-01-01
>
>>
>>
>> Warning message:
>> In `[<-.factor`(`*tmp*`, list, value = "-") :
>>  invalid factor level, NAs generated
>>
>> Is there any other method of doing it? or am i missing something?. 
>> please
>> let me know if you need any more information.
>>
>> Thanks.
>>
>> Prem
>> -- 
>> View this message in context: 
>> http://n4.nabble.com/Replace-with-in-date-tp1911391p1911391.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
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>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius, MD
> West Hartford, CT
>
> ______________________________________________
> 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.


-- 
Christian Raschke
Department of Economics
and
ISDS Research Lab (HSRG)
Louisiana State University
Patrick Taylor Hall, Rm 2128
Baton Rouge, LA 70803
crasch2 at lsu.edu