z-optimal FAB t-interval

Computation of a 1-alpha FAB t-interval using z-optimal spending function

fabtzCI(y, s, dof, alpha = 0.05, psi = list(mu = 0, tau2 = 1e+05, sigma2 = 1))

Arguments

y

a numeric scalar, a normally distributed statistic
s

a numeric scalar, the standard error of y
dof

positive integer, degrees of freedom for s
alpha

the type I error rate, so 1-alpha is the coverage rate
psi

a list of parameters for the spending function, including

  1. mu, the prior expectation of E[y]

  2. tau2, the prior variance of E[y]

  3. sigma2 the variance of y

Value

a two-dimensional vector of the left and right endpoints of the interval

Author

Peter Hoff

Examples

n<-10 
y<-rnorm(n) 
fabtzCI(mean(y),sqrt(var(y)/n),n-1)  

#> [1] -1.2408834  0.3581589
t.test(y)$conf.int 

#> [1] -1.2408908  0.3581618
#> attr(,"conf.level")
#> [1] 0.95