Re: [R] Identify first row of each ID within a data frame, create a variable first =1 for the first row and first=0 of all other rows

Dear Colleagues, I am grateful to all of you for helping me with my question, how to write R code that will identify the first row of each ID within a data frame, create a variable first=1 for the first row and first=0 for all repeats of the ID. WOW!!! I just saw Boris Steipe's answer to my que

Re: [R] Identify first row of each ID within a data frame, create a variable first =1 for the first row and first=0 of all other rows

John, Thanks for enlightening us so we better understand. I won't argue with your wish to learn to do things in base R first. I started that way, myself, and found lots of the commands not particularly easy to fit into a single worldview. Many functions I read about were promptly forgotten, es