[R] loop

Omar Lakkis uofiowa at gmail.com
Wed May 18 22:58:13 CEST 2005


Rather than using a loop, how can I remove all consequentially
repeated values as in this example?
I am guessing using diff would help but not quite sure how.

> get
> s
        date          f  
1 1999-01-01 1
2 1999-01-02 1
3 1999-01-03 1
4 1999-01-04 2
5 1999-01-05 2

> v <- s[1,'f']; for (i in 2:nrow(s)) { if (s[i,'f'] == v) s[i,'f'] <- NA else v <- s[i,'f'] }
> s <- s[!is.na(s$f),]
> s
        date          f
1 1999-01-01 1
4 1999-01-04 2




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