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Using summaryBy with weighted data

10 messages · Joshua Wiley, David Freedman, S. Messing +4 more

Joshua Wiley
# 
Dear Solomon,

On Sun, Jan 16, 2011 at 10:27 PM, Solomon Messing
<solomon.messing at gmail.com> wrote:
Yes, of course.  It has no way of knowing that the weights should also
be being broken down by group....they are not in the formula.
Ideally there would be a way to pass more than one variable to a
function (e.g., response and weights) or just an entire object
(mydata) broken down by group.  Then you would just make a wrapper
function to pass the right values to the x and w arguments of
weighted.mean.  Instead here is a somewhat hacked version:

library(doBy)
## make up some data (easier)
mydata <- data.frame(response = rnorm(100),
 group = rep(1:5, each = 20), weights = runif(100, 0, 1))

## manually compute weighted mean
tmp <- summaryBy(response*weights ~ group, data = mydata, FUN = sum)
tmp[,2] <- tmp[,2]/with(mydata, tapply(weights, group, sum))
tmp ## weighted means

## here's the 'problem', if you will, even with  +, they are passed
one at a time
summaryBy(response + weights ~ group, data = mydata, FUN = str)
summaryBy(mydata ~ group, data = mydata, FUN = str)

## here is an option using by():
xy <- by(mydata, mydata$group, function(z) weighted.mean(z$response, z$weights))
xy
## if you don't like the formatting....
data.frame(group = names(c(xy)), weighted.mean = c(xy))

HTH,

Josh

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      David Freedman
    

    

      
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You might use the plyr package to get group-wise weighted means

library(plyr)
ddply(mydata,~group,summarise, b=mean(weights),
c=weighted.mean(response,weights))

hth
david freedman

  
    

      
      
    

  


  


      

    

    

      
      

        
      

    

    

      
      

        
      

    

    

      
      

        


  

        

      Søren Højsgaard
    

    

      
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It is currently not possible to pass weights in summaryBy.
Regards
S?ren 

________________________________________
Fra: Joshua Wiley [jwiley.psych at gmail.com]
Sendt: 17. januar 2011 08:16
Til: Solomon Messing
Cc: r-help at r-project.org; S?ren H?jsgaard
Emne: Re: [R] Using summaryBy with weighted data

Dear Solomon,

On Sun, Jan 16, 2011 at 10:27 PM, Solomon Messing

        
<solomon.messing at gmail.com> wrote:

            

      
      
      
    

        
Yes, of course.  It has no way of knowing that the weights should also
be being broken down by group....they are not in the formula.

            

      
      
      
    

        
Ideally there would be a way to pass more than one variable to a
function (e.g., response and weights) or just an entire object
(mydata) broken down by group.  Then you would just make a wrapper
function to pass the right values to the x and w arguments of
weighted.mean.  Instead here is a somewhat hacked version:

library(doBy)
## make up some data (easier)
mydata <- data.frame(response = rnorm(100),
 group = rep(1:5, each = 20), weights = runif(100, 0, 1))

## manually compute weighted mean
tmp <- summaryBy(response*weights ~ group, data = mydata, FUN = sum)
tmp[,2] <- tmp[,2]/with(mydata, tapply(weights, group, sum))
tmp ## weighted means

## here's the 'problem', if you will, even with  +, they are passed
one at a time
summaryBy(response + weights ~ group, data = mydata, FUN = str)
summaryBy(mydata ~ group, data = mydata, FUN = str)

## here is an option using by():
xy <- by(mydata, mydata$group, function(z) weighted.mean(z$response, z$weights))
xy
## if you don't like the formatting....
data.frame(group = names(c(xy)), weighted.mean = c(xy))

HTH,

Josh

            

      
      
      
    

        

      
      
    

        
--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/

  
  


  


      

    

    

      
      

        
      

    

    

      
      

        


  

        

      Sebastián Daza
    

    

      
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Hi everyone,
I am trying to run Sweave.bat (batchfiles_0.6-1) from the command line 
on Windows, but I get this error:

C:\batchfiles_0.6-1>Sweave.bat Sweave-test-1
"Error: rterm.exe not found"

I don't know how to set up the path if this one were the problem... I 
ran rcmd.bat and I got this... so I don't know if it is a path problem.

C:\batchfiles_0.6-1>Rcmd,bat
R_ARCH=/x64
R_ARCH0=x64
R_ARCH0=x64
cmdpath=C:\R\R-2.12.1\bin\x64\Rcmd.exe
args=,bat
'bat' is not recognized as an internal or external command,
operable program or batch file.

the path of rterm.exe in my computer is: C:\R\R-2.12.1\bin\x64
thank you in advance!

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Sebastián Daza
    

    

      
      #
    

  


  

      
Hi everyone,
I am trying to run Sweave.bat (batchfiles_0.6-1) from the command line 
on Windows, but I get this error:

C:\batchfiles_0.6-1>Sweave.bat Sweave-test-1
"Error: rterm.exe not found"

I don't know how to set up the path if this one were the problem... I 
ran rcmd.bat and I got this... so I don't know if it is a path problem.

C:\batchfiles_0.6-1>Rcmd,bat
R_ARCH=/x64
R_ARCH0=x64
R_ARCH0=x64
cmdpath=C:\R\R-2.12.1\bin\x64\Rcmd.exe
args=,bat
'bat' is not recognized as an internal or external command,
operable program or batch file.

the path of rterm.exe in my computer is: C:\R\R-2.12.1\bin\x64
thank you in advance!

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Gabor Grothendieck
    

    

      
      #
    

  


  

      
2011/1/17 Sebasti?n Daza <sebastian.daza at gmail.com>:

            

      
      
      
    

        
You should not have to set up any paths. The whole point of these
batch commands are to save you from doing that.  If you contact me
privately we can try to determine what has gone wrong with Sweave.bat
.

Regarding Rcmd.bat, the comma in your command line should be a dot.