The structure of survey design objects changed in version 2.9, to allow
standard errors based on multistage sampling. as.svydesign
converts an
object to the new structure and .svycheck
warns if an object
does not have the new structure.
You can set options(survey.want.obsolete=TRUE)
to suppress the
warnings produced by .svycheck
and
options(survey.ultimate.cluster=TRUE)
to always compute
variances based on just the first stage of sampling.
as.svydesign2(object)
.svycheck(object)
Object of class survey.design2
produced by svydesign
svydesign
, svyrecvar