tapply on multiple groups

Can you make tapply break down groups similar to bwplot or such? Example:

Data frame has one measure (Days) and two Dimensions (YYYYMM and Place). All
have the same length.
length(dbs.final$Days)
[1] 3306
length(dbs.final$Place)
[1] 3306
length(dbs.final$YYYYMM)
[1] 3306

Doing the following makes a nice table for one dimension and one measure:

    do.call(rbind,tapply(dbs.final$Days,dbs.final$Place, summary))

But, what I really need to do is break it down on two dimensions and one
measures - effectively equivalent to the following bwplot call:

    bwplot( Days ~ YYYYMM | Place, ,data=dbs.final)

Is there an equivalent to the "|" operation in tapply?
View this message in context: http://n4.nabble.com/tapply-on-multiple-groups-tp1380593p1380593.html
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Can you make tapply break down groups similar to bwplot or such?  
Example:

Data frame has one measure (Days) and two Dimensions (YYYYMM and  
Place). All
have the same length.

length(dbs.final$Days)
[1] 3306
length()
[1] 3306
length()
[1] 3306

Doing the following makes a nice table for one dimension and one  
measure:

   do.call(rbind,tapply(dbs.final$Days,dbs.final$Place, summary))

But, what I really need to do is break it down on two dimensions and  
one
measures - effectively equivalent to the following bwplot call:

   bwplot( Days ~ YYYYMM | Place, ,data=dbs.final)

Is there an equivalent to the "|" operation in tapply?
Please reread the help page for tapply.

Perhaps?:

tapply(dbs.final$Days, list(dbs.final$YYYYMM, dbs.final$Place) summary)

-- David
-- 
View this message in context: http://n4.nabble.com/tapply-on-multiple-groups-tp1380593p1380593.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
Thanks. My mistake was that I used c(dbs.final$Days,dbs.final$Place) instead of list(... when I tried to follow that part of the documentation.
David Winsemius <dwinsemius at comcast.net> 1/28/2010 11:49 AM >>>

Can you make tapply break down groups similar to bwplot or such?  
Example:

Data frame has one measure (Days) and two Dimensions (YYYYMM and  
Place). All
have the same length.

length(dbs.final$Days)
[1] 3306
length()
[1] 3306
length()
[1] 3306

Doing the following makes a nice table for one dimension and one  
measure:

   do.call(rbind,tapply(dbs.final$Days,dbs.final$Place, summary))

But, what I really need to do is break it down on two dimensions and  
one
measures - effectively equivalent to the following bwplot call:

   bwplot( Days ~ YYYYMM | Place, ,data=dbs.final)

Is there an equivalent to the "|" operation in tapply?
Please reread the help page for tapply.

Perhaps?:

tapply(dbs.final$Days, list(dbs.final$YYYYMM, dbs.final$Place) summary)

-- David
-- 
View this message in context: http://n4.nabble.com/tapply-on-multiple-groups-tp1380593p1380593.html 
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help 
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html 
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT