Aggregation using list with Hmisc summarize function

An embedded and charset-unspecified text was scrubbed...
Name: not available
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20061228/9204583f/attachment.pl
Hi All,

I'm using the Hmisc summarize function and used list instead of llist to
provide the by variables. It generated an error message. Is this a bug,
or do I misunderstand how Hmisc works with lists? The program below
demonstrates the error message.

Thanks,

Bob

x<-1:8

group <- c(1,1,1,1,2,2,2,2)

gender<- c(1,2,1,2,1,2,1,2)

mydata<-data.frame(x,group,gender)

attach(mydata)

# Creating a list using Hmisc llist works:

summarize(x, by=llist(group,gender), FUN=mean, na.rm=TRUE) 

# Creating a list using built-in list function does not:

summarize(x, by= list(group,gender), FUN=mean, na.rm=TRUE)
Use llist so summarize will know how to label the output.

Also your attach( ) is not functional as your variables are already in 
the search path.  Whenever you do need to attach, consider the use of 
with( ) instead.

Frank

=========================================================
Bob Muenchen (pronounced Min'-chen), Manager 
Statistical Consulting Center
U of TN Office of Information Technology

Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University
Note that you don't really need list or llist in this case:

summarize(x, by = mydata[2:3], FUN = mean, na.rm = TRUE)

Also you could use aggregate:

aggregate(mydata[1], mydata[2:3], mean, na.rm = TRUE)
Hi All,

I'm using the Hmisc summarize function and used list instead of llist to
provide the by variables. It generated an error message. Is this a bug,
or do I misunderstand how Hmisc works with lists? The program below
demonstrates the error message.

Thanks,

Bob

x<-1:8

group <- c(1,1,1,1,2,2,2,2)

gender<- c(1,2,1,2,1,2,1,2)

mydata<-data.frame(x,group,gender)

attach(mydata)

# Creating a list using Hmisc llist works:

summarize(x, by=llist(group,gender), FUN=mean, na.rm=TRUE)

# Creating a list using built-in list function does not:

summarize(x, by= list(group,gender), FUN=mean, na.rm=TRUE)

=========================================================
Bob Muenchen (pronounced Min'-chen), Manager
Statistical Consulting Center
U of TN Office of Information Technology
200 Stokely Management Center, Knoxville, TN 37996-0520
Voice: (865) 974-5230
FAX: (865) 974-4810
Email: muenchen at utk.edu
Web: http://oit.utk.edu/scc <http://oit.utk.edu/scc> ,
News: http://listserv.utk.edu/archives/statnews.html
<http://listserv.utk.edu/archives/statnews.html>
=========================================================

       [[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
and provide commented, minimal, self-contained, reproducible code.