svycontrast {survey} | R Documentation |
Computes linear or nonlinear contrasts of estimates produced by survey
functions (or any object with coef
and vcov
methods).
svycontrast(stat, contrasts, ...)
stat |
object of class svrepstat or svystat |
contrasts |
A vector or list of vectors of coefficients, or a call or list of calls |
... |
For future expansion |
If contrasts
is a list, the element names are used as
names for the returned statistics.
If an element of contrasts
is shorter than coef(stat)
and has names, the
names are used to match up the vectors and the remaining elements of
contrasts
are assumed to be zero. If the names are not legal
variable names (eg 0.1
) they must be quoted (eg "0.1"
)
If contrasts
is a "call"
or list of "call"s
, the
delta-method is used to compute variances, and the calls must use only
functions that deriv
knows how to differentiate. If the
names are not legal variable names they must be quoted with backticks
(eg `0.1`
).
Object of class svrepstat
or svystat
regTermTest
, svyglm
data(api) dclus1<-svydesign(id=~dnum, weights=~pw, data=apiclus1, fpc=~fpc) a <- svytotal(~api00+enroll+api99, dclus1) svycontrast(a, list(avg=c(0.5,0,0.5), diff=c(1,0,-1))) ## if contrast vectors have names, zeroes may be omitted svycontrast(a, list(avg=c(api00=0.5,api99=0.5), diff=c(api00=1,api99=-1))) ## nonlinear contrasts svycontrast(a, quote(api00/api99)) svyratio(~api00, ~api99, dclus1)