[R] Help with which()

[Erik Iverson]

See

http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f

naw3 at duke.edu wrote:
> Hi,
> 
> I'm using which to find the position of a value in my data table, and it is
> returning the correct position and the position of another number that differs
> by an extra decimal place. For example, when I do:
> 
> where1<-which(Operons==3573.1,arr.ind=TRUE)
> 
> it returns the position of that number and of 3573.15.
> 
> Is it possible to get the function to only return a position if the number
> matches exactly?
> 
> Thanks,
> -Nina
> 
> ______________________________________________
> 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.