as.powerprior: Convert RBesT mix object into powerprior object

In wiesenfa/ESS: Quantification of prior informativeness in terms of prior effective and effective current sample size

Description

Convert RBesT mix object into powerprior object allowing the computation of empirical Bayes power priors (Gravestock&Held, 2017).

Usage

as.powerprior(prior, p.prior.a = 1, p.prior.b = 1)

Arguments

prior	An RBesT betaMix or normMix mixture object with a single mixture component
p.prior.a	in case of binary outcome, shape1 parameter of initial beta prior for successes
p.prior.b	in case of binary outcome, shape2 parameter of initial beta prior for successes

Value

A powerprior object which can be used, e.g. in postmix.powerprior to compute posterior.

Author(s)

Manuel Wiesenfarth

References

Gravestock, I. and Held, L. (2017). Adaptive power priors with empirical bayes for clinical trials. Pharmaceutical statistics, 16(5):349-360.

See Also

package StudyPrior

Examples

######################
# Normal Outcome
  # standard deviation
    sigma=1
  # prior with nominal prior ESS=50
    info <-mixnorm(informative=c(1, 0,1/sqrt(50)), sigma=sigma)
  
  n=10 # sample size

  m=0 #data mean equal to prior mean
  postmix(info,m=m,se=sigma/sqrt(n))
  postmix(as.powerprior(info),m=m,se=sigma/sqrt(n))
  m=2 #prior-data conflict
  postmix(info,m=m,se=sigma/sqrt(n))
  postmix(as.powerprior(info),m=m,se=sigma/sqrt(n)) #variance inflation

wiesenfa/ESS documentation built on June 19, 2019, 4:19 p.m.