[R] Count Code

[David Winsemius]

On Apr 22, 2009, at 3:42 PM, Bronagh Grimes wrote:

> Hi there,
> I am interested in converting SAS code to R & I wondered if anyone had
> any quick R code/tips for the following piece of test SAS code?
>
> Any feedback greatly appreciated.
>
> data A1;
>   set A1;
>  count + 1;
>  by subject_id;
>  if first.subject_id then count = 1;
> run;

There were several solution offered a couple of months back to the  
challenge of replicating the features of the SAS _N_ construct. At  
least that is my memory of how it looks in SAS. You probably have the  
right books to consult for that question to construct a proper search:

http://search.r-project.org/nmz.html

David Winsemius, MD
Heritage Laboratories
West Hartford, CT