[R] Substitute value

[Gabor Grothendieck]

On Fri, Mar 8, 2013 at 5:23 AM, chris201 <chris.r.bennett at btinternet.com> wrote:
> Hi,
> I have a large data frame and within this there is one column which contains
> individual codes (eg. 1.1234.2a.2).  I am splitting these codes into their 4
> components using strsplit (eg. "1", "1234", "2a", "2").  However there are
> some individual codes which do not have a last component (eg. 2.4356.3b. ),
> I want to give these codes a "1" as their last component (eg. 2.4356.3b.1)
> but I can't get it to work.
>
> This is my example and attempt:
>
> sim.code<-c("1.1234.1a.1","1.1234.1a.2","1.3245.2c.5","4.6743.3c.","4.3254.6b.4","3.5463.2a.")
> sim.val<-c(4,5,3,6,4,7)
> sim.df<-data.frame(sim.code,sim.val)
>
> sim.df$sim.code2<-sub(".$",".1",sim.df$sim.code)
> sim.df
>
> but this changes all the ends to ".1"
>

1. Use "\\.$" like this:

sim.code.1 <- sub("\\.$", ".1", sim.code)
read.table(text = sim.code.1, sep = ".")

2. or without regular expressions

DF <- read.table(text = sim.code, sep = ".")
DF[is.na(DF)] <- "1"


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