[R] How to create these variables in R?

[Faradj Koliev]

Dear all, 

Let’s say that I have a dataset that looks something like this: 


Subject Year    A   
    A   1990    1   
    A   1991    1   
    A   1992    1   
    A   1993    1   
    A   1994    0   
    A   1995    0   
    B   1990    1   
    B   1991    0   
    B   1992    1   
    B   1993    1   
    C   1991    1   
    C   1992    1   
    C   1993    0   
    C   1994    1   
    D   1991    0   
    D   1992    1  
    D   1993    1   
    D   1994    0   
    D   1995    0   
    D   1996    1   
    D   1997    1   


What I would like to do is to create the following three new variables: A1, A2, and A3 
The variable A1 should capture/count all 1’s in the variable A that are in a row (counting), for each subject-year – but it  should restart counting if there 
are two 0’s in a row (displayed 
below). 

The variable A2 should capture 1-2’s (range) in the A1. Displayed in the example below.(subject-year) 

The variable A3 should capture all values in the variable A1 that are more than 2, also displayed in the example data below.(subject-year) 


See the example below for illustration of these variables


Subject Year    A   A1  A2  A3
    A   1990    1   1   1   0
    A   1991    1   2   1   0
    A   1992    1   3   0   1
    A   1993    1   4   0   1
    A   1994    0   0   0   0
    A   1995    0   0   0   0
    B   1990    1   1   1   0
    B   1991    0   1   1   0
    B   1992    1   2   1   0
    B   1993    1   3   0   1
    C   1991    1   1   1   0
    C   1992    1   2   1   0
    C   1993    0   2   1   0
    C   1994    1   3   0   1
    D   1991    0   0   0   0
    D   1992    1   1   1   0
    D   1993    1   2   1   0
    D   1994    0   0   0   0
    D   1995    0   0   0   0
    D   1996    1   1   1   0
    D   1997    1   2   1   0


I’ve no clue where to start at this stage –I’d appreciate any suggestions and help. 



	[[alternative HTML version deleted]]