Following David example if i just wanted to do means
would multiplying the cases according to the weight do the work?


Something like this on a data.frame
(Must be a simpler way to do it with R - the sapply scope confused me)


weightBy <- function(origDataFrame,weightVector)
{
    case_Number_After_Weighting = sum(weightVector);
    #print ( "case_Number_After_Weighting  =
");#print(case_Number_After_Weighting );

    data.weighted.local = data.frame ( 1:case_Number_After_Weighting );
    assign("data.weighted.tmp",data.weighted.local,env=globalenv())

    sapply(1:NCOL(origDataFrame),
        function(colNo) {
            #print ( "dealing with colomn ");#print(colNo);
            data.weighted.tmp[,colNo] =
                 unlist(
                    sapply(1:NROW(origDataFrame),
                        function(x) rep(origDataFrame[x,colNo],
times=weightVector[x] )
                    )
                )
            names(data.weighted.tmp)[colNo] <- names(origDataFrame)[colNo]
            assign("data.weighted.tmp",data.weighted.tmp,env=globalenv())

            #print (data.weighted.tmp);
        }
    )
    data.weighted.local = data.weighted.tmp;
    rm(data.weighted.tmp, envir=globalenv());
    return(data.weighted.local);
}



data.recieved <- data.frame(
    f1 = factor(c(2,1,1,1), labels = c("Yes", "No")),
    f2 = factor(c(1,2,3,4), labels = c("One", "Two","Three","Four"))
);

weight=c(10, 1, 1, 1)


weightBy(data.recieved,weight);



On Fri, Feb 24, 2012 at 8:03 AM, Thomas Lumley <tlumley@uw.edu> wrote:

> >On Fri, Feb 24, 2012 at 9:40 AM, David Winsemius <dwinsemius@comcast.net>
> wrote:
> >
> > On Feb 23, 2012, at 3:27 PM, Hed Bar-Nissan wrote:
> >
> >> It's really weighting - it's just that my simplified example was too
> >> simplified
> >> Here is my real weight vector:
> >> > sc$W_FSCHWT
> >>  [1]  14.8579  61.9528   3.0420   2.9929   5.1239  14.7507   2.7535
> >> 2.2693   3.6658   8.6179   2.5926   2.5390   1.7354   2.9767   9.0477
> >> 2.6589   3.4040   3.0519
> >> ....
> >
> >
> > You should always convey the necessary complexity of the problem.
> >
> >>
> >>
> >> And still it should somehow set the case weight.
> >> I could multiply all by 10000 and use maybe your method but it would
> >> create such a bloated dataframe
> >>
> >> working with numeric only i could probably create weighted means
> >>
> >> But something simple as WEIGHTED BY would be nice.
> >
> >
> > The survey package by Thomas Lumley provides for a wide variety of
> weighted
> > analyses.
>
> Yes.  It doesn't do everything that SPSS WEIGHTED BY will do, but it
> does a lot.  SPSS is more general partly because it cheats -- it
> doesn't always compute the right standard errors if the weights are
> sampling weights   [SPSS now has some proper survey analysis commands,
> which do get the right standard errors, but are more limited]
>
>  - thomas
>
> --
> Thomas Lumley
> Professor of Biostatistics
> University of Auckland
>

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