Thanks a lot match() function does the task (of course this a a simple example of my long datasets) Just for the record, merge() function does not seem to work properly for this (even with the sort=FALSE argument) as the order of the results does not match the corresponding order of classes in the x vector.
Wishes, Javier ------------------------------------------------------- Tony Plate wrote: > > a <- data.frame(value=c(6.5,7.5,8.5,12.0),class=c(1,3,5,2)) > > x <- c(1,1,2,7,6,5,4,3,2,2,2) > > match(x, a$class) > [1] 1 1 4 NA NA 3 NA 2 4 4 4 > > a[match(x, a$class), "value"] > [1] 6.5 6.5 12.0 NA NA 8.5 NA 7.5 12.0 12.0 12.0 > > > > -- Tony Plate > > javier garcia-pintado wrote: >> Hello, >> In a nutshell, I've got a data.frame like this: >> >> >>> assignation <- data.frame(value=c(6.5,7.5,8.5,12.0),class=c(1,3,5,2)) >>> assignation >> >> value class >> 1 6.5 1 >> 2 7.5 3 >> 3 8.5 5 >> 4 12.0 2 >> >>> >> >> >> and a long vector of classes like this: >> >> >>> x <- c(1,1,2,7,6,5,4,3,2,2,2...) >> >> >> And would like to obtain a vector of length = length(x), with the >> corresponding values extracted from assignation table. Like this: >> >>> x.value >> >> [1] 6.5 6.5 12.0 NA NA 8.5 NA 7.5 12.0 12.0 12.0 >> >> Could you help me with an elegant way to do this ? >> (I just can do it with looping for each class in the assignation table, >> what a think is not perfect in R's sense) >> >> Wishes, >> Javier >> >> >> ------------------------------------------------------------------------ >> >> ______________________________________________ >> [email protected] 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. > > -- Javier García-Pintado Institute of Earth Sciences Jaume Almera (CSIC) Lluis Sole Sabaris s/n, 08028 Barcelona Phone: +34 934095410 Fax: +34 934110012 e-mail:[EMAIL PROTECTED]
______________________________________________ [email protected] 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.
