R: [R] removing observations

[8rino-Luca Pantani]

"by" is perhaps what you looking for
try to write "?by" for help

>I have a panel data set (25 years) and I would like to break 
>it up by year, and run a few tests.  How is this done in R?  
>In STATA it is quite simple (keep if year =1970).  If someone 
>could give me an example of how to do it for a single year I 
>am sure I could make a little loop to do it for all 25.

Otto