R help - Mar 2012 - output by(...)

Dear all,

I have a question that is probably pretty stupid, so apologies in advance...

I do a simple
> mydata.tab <- by(my.data.frame, my.data.frame$category, colMeans)
...works fine, but I need to output the results to some "flat" file
(kind of table) to work with it in Excel etc.

So I am doing now
> capture.output(data.frame(unlist(mydata.tab)), file="mydata.txt")
...and process the result in Excel.
Do you know a more pretty way to do this task? Perhaps something other than
'by()' to make a table of colMeans?

Many thanks!
Zdenek

2012/3/25 Sk?la, Zden?k (INCOMA GfK) <Zdenek.Skala at
gfk.com>:
> Dear all,
>
> I have a question that is probably pretty stupid, so apologies in
advance...
>
> I do a simple
>
>> mydata.tab <- by(my.data.frame, my.data.frame$category, colMeans)
>
> ...works fine, but I need to output the results to some "flat"
file (kind of table) to work with it in Excel etc.
>
> So I am doing now
>
>> capture.output(data.frame(unlist(mydata.tab)),
file="mydata.txt")
>
> ...and process the result in Excel.
> Do you know a more pretty way to do this task? Perhaps something other than
'by()' to make a table of colMeans?
>
Try this:

do.call("rbind", by(iris[-5], iris[[5]], colMeans))




-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com