[R] Retain last grouping after a strsplit()

[Steven Ranney]

All -

I have a column of SiteNames:

SiteName
OYS-PIA2-FL-1
OYS-PIA2-LA-1
OYS-PI-LA-BB-1
OYS-PIA2-LA-10
...
[truncated]

and I want to include only the last few digits into a new column.

I tried

substr(data$SiteName, 13, 20)

but because some SiteName values are of a different length, the final
hyphen (i.e., "-") was included:

"1"
"1"
"-1"
"10"
...

 so I use

strsplit(data$SiteName, split = "-")

and get

"OYS" "PIA2" "FL" "1"
"OYS" "PIA2" "LA" "1"
"OYS" "PI" "LA" "BB" "1"
"OYS" "PIA2" "LA" "10"
...

which is great.  Unfortunately, I'm stuck.  I don't know how to
retrieve the final grouping of information from the strsplit()
statement I called into a new column.

Can you help?

Thanks -

SR
Steven H. Ranney