CI from svyquantile in survey package
I am having trouble understanding (i.e. getting) confidence intervals from
the survey package. I am using R version 2.8.1 (2008-12-22) and survey
package (3.11-2) on FC7 linux. To simplify my question I use an example from
that package:
R> data(api)
R> dclus1<-svydesign(id=~dnum, weights=~pw, data=apiclus1, fpc=~fpc)
R> (tst <- svyby(~api99, ~stype, dclus1, svyquantile,
quantiles=0.5,ci=TRUE))
stype api99 se
E E 615 37.89
H H 593 69.52
M M 611 37.67
R> str(tst)
Classes ???svyby??? and 'data.frame': 3 obs. of 3 variables:
$ stype: Factor w/ 3 levels "E","H","M": 1 2 3
$ api99: num 615 593 611
$ se : num 37.9 69.5 37.7
- attr(*, "svyby")=List of 7
..$ margins : int 1
..$ nstats : num 1
..$ vars : int 1
..$ deffs : logi FALSE
..$ statistic: chr "svyquantile"
..$ variables: chr "api99"
..$ vartype : chr "se"
- attr(*, "call")= language svyby.default(~api99, ~stype, dclus1,
svyquantile, quantiles = 0.5, ci = TRUE)
R>
I do not see the CI in this structure. Specifically, this problem came up
when I was working through an example where after a similar set up
information was extracted using
R> tst$statistics.quantiles
NULL
R> tst$statistics.CIs
NULL
where of course the NULLs I get are due, in my case, to the absences of the
$statistics.XXXs. The example did not display the structure so I could not
compare my output with their output. (The example warns that these objects
need to be unlisted which is not relevant here)
Thanks in advance for any help
Ron
R. R. Burns Oceanside, CA