Re: A (probably) trivial question about first occurrence in unique()

[Tim Hesterberg <timh@insightful.com>]

Recent versions of S+ have duplicated.data.frame.
So if your data are in a data frame "data", you could pass
that function the data frame with the two columns, and use
that to subscript rows of the original data frame:

data[ !duplicated(data[c("STREETS","MUNIC")]), ]

Tim Hesterberg

>I have data for 300000 road segments reflecting approximately 60000 
>unique street names.  I would like to create a new data frame with 
>the unique street names and their first-occurrence municipalities 
>(they are sorted North to South).  Of course unique(STREETS) gives me 
>the first part, but is there some way to get the MUNIC of the first 
>occurrence without writing a loop?