On Tue, 17 Aug 2010, Marc Zodet wrote:
> svymean w/ svyby is working for me...
>
>> svyby(~visitcnt, ~agegrp3.f, svymean, design=svydes)
> agegrp3.f visitcnt se.visitcnt
> 18-44 18-44 8.755552 0.4953235
> 45-64 45-64 10.131555 0.5347806
> 65+ 65+ 9.588802 0.4323629
>
> svyquantile is working for me...
>
>> svyquantile(~visitcnt, quantiles=c(.25, .5, .75),
ties="rounded", design=svydes)
> 0.25 0.5 0.75
> visitcnt 3.021468 6.039823 11.49518
>
> svyquantile w/ svyby is bombing on me...
>
>> svyby(~visitcnt, ~agegrp3.f, svyquantile, quantiles=c(.25, .5, .75),
ties="rounded", design=svydes)
> Error in object$coefficients : $ operator is invalid for atomic vectors
>
> i'm not sure what i'm missing/not understanding.
>
svyquantile() doesn't produce standard errors by default. So you either need
to ask for standard errors from svyquantile() or tell svyby() not to expect them
> svyby(~api99, ~stype, dclus1, svyquantile, quantiles=c(0.25,0.5), ci=TRUE)
stype 0.25 0.5 se.0.25 se.0.5
E E 512 615 22.80167 37.89113
H H 482 593 42.68682 69.52309
M M 518 611 54.22614 37.66903> svyby(~api99, ~stype, dclus1, svyquantile, quantiles=c(0.25,0.5),
keep.var=FALSE)
stype statistic1 statistic2
E E 512 615
H H 482 593
M M 518 611
The help page does say "svyquantile needs ci=TRUE or keep.var=FALSE."
-thomas
Thomas Lumley
Professor of Biostatistics
University of Washington, Seattle