[R] count the cumulative for each subject

[Bart Joosen]

Peter,

After I made a small modification it worked:
with(dat, ave(x1, subject, FUN=cumsum))

But what's the use of with?
If I use ave(x1, subject, FUN=cumsum), I get the same result?

Bart

----- Original Message ----- 
From: "Bart Joosen" <Bartjoosen at hotmail.com>
To: "Peter Dalgaard" <P.Dalgaard at biostat.ku.dk>
Cc: <r-help at r-project.org>
Sent: Monday, November 24, 2008 7:29 PM
Subject: Re: [R] count the cumulative for each subject


> Peter,
>
> I actually took a look at the ave function, but couldn't manage to get it 
> right.
> But when I try your code, I get "Error in as.vector(x, mode) : invalid 
> argument 'mode'".
> Any ideas?
>
> Bart
>
> ----- Original Message ----- 
> From: "Peter Dalgaard" <P.Dalgaard at biostat.ku.dk>
> To: "bartjoosen" <bartjoosen at hotmail.com>
> Cc: <r-help at r-project.org>
> Sent: Monday, November 24, 2008 3:42 PM
> Subject: Re: [R] count the cumulative for each subject
>
>
> bartjoosen wrote:
>> How about:
>>
>> tapply(dat$x1,dat$subject,function(x) cumsum(x))
>> which gives you a list for each subject.
>>
>> this can be converted to a vector:
>> do.call("c",tapply(dat$x1,dat$subject,function(x) cumsum(x)))
>>
>> So if your data frame is ordered for your subjects:
>>
>> cbind(your.data.frame,do.call("c",tapply(dat$x1,dat$subject,function(x)
>> cumsum(x))))
>>
>>
>
> Sounds like a job for the eternally overlookked ave() function:
>
> with(dat, ave(x1, subject, cumsum))
>
>
> -- 
>   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
> (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907
>
>