svyttest {survey}

Design-based t-test

Description

One-sample or two-sample t-test. This function is a wrapper for svymean in the one-sample case and for svyglm in the two-sample case. Degrees of freedom are degf(design)-1 for the one-sample test and degf(design)-2 for the two-sample case.

Usage

svyttest(formula, design,  ...)

Arguments

formula

Formula, outcome~group for two-sample, outcome~0 or outcome~1 for one-sample. The group variable must be a factor or character with two levels, or be coded 0/1 or 1/2

design

survey design object

...

for methods

Value

Object of class htest

See Also

t.test

Examples

data(api)
dclus2<-svydesign(id=~dnum+snum, fpc=~fpc1+fpc2, data=apiclus2)
tt<-svyttest(enroll~comp.imp, dclus2)
tt
confint(tt, level=0.9)

svyttest(enroll~I(stype=="E"),dclus2)

svyttest(I(api00-api99)~0, dclus2)