[R] Extracting a numeric prefix from a string

R user R-user at zutt.org
Mon Jan 31 10:33:37 CET 2005


You could use something like

y <- gsub('([0-9]+(.[0-9]+)?)?.*','\\1',x)
as.numeric(y)

But maybe there's a much nicer way.

Jonne.

On Mon, 2005-01-31 at 08:51 +0000, Mike White wrote:
> Hi
> Does anyone know if there is a function similar to as.numeric that will
> extract a numeric prefix from a string as in the following examples?
> 
> x<-c(3, "abc", 5.67, "2.4a", "6a", "6b", "2.4.a", 3, "4.2a")
> df.x<-data.frame(Code=x)
> x.str<-levels(df.x[,1])
> # required function  result
> 2.40 3.00 4.20 5.67 6.00 NA
> 
> Thanks
> Mike White
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
-- 
R user <R-user at zutt.org>




More information about the R-help mailing list