R help - Feb 2011 - Weighted Mean By Factor Using "BY"

Hello R folks,

Reproducible code below - I'm trying to do a weighted mean by a factor and
can't figure it out.  Thanks in advance for your assistance.

Mike

data<-data.frame(c(5,5,1,1,1),
                                c(10,8,9,5,3),
                               
c("A","A","A","B","B"))

names(data)<-c("COUNT","MEASURE","TYPE")

## UNWEIGHTED MEAN BY TYPE
by(data$MEASURE,data$TYPE,mean)

## WEIGHTED MEAN WITHOUT TYPE
weighted.mean(x=data$MEASURE,w=data$COUNT)

## WEIGHTED MEAN BY TYPE - DOESNT WORK
by(data$MEASURE,data$TYPE,weighted.mean(x=data$MEASURE,w=data$COUNT))




-- 
Michael Schumacher
Manager, Data and Analytics
ValueClick
mike.schumacher@gmail.com

	[[alternative HTML version deleted]]

I withdraw this question, I was able to accomplish this by creating a new
function.

Now if only I could get the by output into a dataframe...

Mike

On Wed, Feb 23, 2011 at 2:25 PM, Mike Schumacher
<mike.schumacher@gmail.com>wrote:
> Hello R folks,
>
> Reproducible code below - I'm trying to do a weighted mean by a factor
and
> can't figure it out.  Thanks in advance for your assistance.
>
> Mike
>
> data<-data.frame(c(5,5,1,1,1),
>                                 c(10,8,9,5,3),
>                                
c("A","A","A","B","B"))
>
> names(data)<-c("COUNT","MEASURE","TYPE")
>
> ## UNWEIGHTED MEAN BY TYPE
> by(data$MEASURE,data$TYPE,mean)
>
> ## WEIGHTED MEAN WITHOUT TYPE
> weighted.mean(x=data$MEASURE,w=data$COUNT)
>
> ## WEIGHTED MEAN BY TYPE - DOESNT WORK
> by(data$MEASURE,data$TYPE,weighted.mean(x=data$MEASURE,w=data$COUNT))
>
>
>
>
> --
> Michael Schumacher
> Manager, Data and Analytics
> ValueClick
> mike.schumacher@gmail.com
>
>
>
>

-- 
Michael Schumacher
mike.schumacher@gmail.com
818-851-8638

	[[alternative HTML version deleted]]