On Mar 3, 2011, at 3:58 PM, JonC wrote:
Hi R helpers,
I'm trying to create a count in R , but as there is no retain
function like
in SAS I'm running into difficulties.
Your data is not cut-pastable as presented but this should work:
> dfrm$count_var <- ave(as.numeric(dfrm$Date_var), dfrm$Date_var,
FUN=seq_along)
> dfrm
Date_var count_var
1 01/01/2011 1
2 01/01/2011 2
3 02/01/2011 1
4 02/01/2011 2
5 02/01/2011 3
6 02/01/2011 4
7 03/01/2011 1
8 03/01/2011 2
9 03/01/2011 3
10 03/01/2011 4
11 03/01/2011 5
12 03/01/2011 6
13 03/01/2011 7
I have the following :
Date_var and wish to obtain Date_var
Count_var
01/01/2011
01/01/2011
1
01/01/2011
01/01/2011
2
02/01/2011
02/01/2011
1
02/01/2011
02/01/2011
2
02/01/2011
02/01/2011
3
02/01/2011
02/01/2011
4
03/01/2011
03/01/2011
1
03/01/2011
03/01/2011
2
03/01/2011
03/01/2011
3
03/01/2011
03/01/2011
4
03/01/2011
03/01/2011
5
03/01/2011
03/01/2011
6
03/01/2011
03/01/2011
7
As can be seen above the count var is re initialised every time a
new date
is found. I hope this is easy.
Many thanks in advance for assistance. It is appreciated.
Cheers
Jon
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______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
