[R] sapply question

Liaw, Andy andy_liaw at merck.com
Wed Jun 28 16:23:02 CEST 2006

If you attached files, none made it through the mailing list.

Can't you try posting a simplified version of the problem instead?  Try to
make it as easy for others to help you as possible will maximize the chance
you get some useful response.  Asking people to read code you've attached in
files isn't helping, especially if the code is long and make use of data not
accessible to anyone but you.

In general, if you want something like tapply, but need several variables
instead of one, you can use something like:

sapply(split(dataFrame, factor_to_split_by), function(...))


From: Afshartous, David
> sent this to the list yesterday but didn't see it listed in 
> the daily summary ... apologies if you receive it twice ...
> ________________________________
> From: Afshartous, David
> Sent: Tuesday, June 27, 2006 10:02 AM
> To: 'r-help at stat.math.ethz.ch'
> Subject: sapply question
> All:
> I'm trying to use sapply to break up data within another function.
> (tapply doens't seem to work since I want to access several 
> variables of
> a 
> data set, not just break up a single variable according to a factor.)
> I tried the R documentation but that wasn't much help on this.
> The first function in the attached file works, breaking up the data
> according to patient number (6 
> observations per 24 patients) via a for loop i=1,..24. 
> The second function is an attempt to use sapply instead of the first
> "for loop".    
> it doesn't load properly and I seem to be absolutely blind as 
> to why; my
> guess is that
> it's something "obvious".  any help appreciated.  (necessary data
> attached)
> thanks!
> dave  
> ps:
> I'm on windows and,
> r.2 =100  (input to function)
> dat = comp.CAND.frm (attached file)
> 	[[alternative HTML version deleted]]
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html

More information about the R-help mailing list