bcrm (version 0.5.4)

getprior: Samples from the specified prior distribution.

Description

A sample of specified size is obtained from the prior distribution.

Usage

getprior(prior.alpha, n)

Arguments

prior.alpha

A list of length 3 containing the distributional information for the prior. The first element is a number from 1-4 specifying the type of distribution. Options are

1. Gamma(a, b), where a=shape, b=scale: mean=a*b, variance=a*b*b

2. Uniform(a, b), where a=min, b=max

3. Lognormal(a, b), where a=mean on the log scale, b=variance on the log scale

4. Bivariate Lognormal(a, b), where a=mean vector on the log scale, b=Variance-covariance matrix on the log scale. This prior should be used only in conjunction with a two-parameter logistic model.

The second and third elements of the list are the parameters a and b, respectively.

n

The number of samples.

Details

A vector of size n is returned from the specified prior distribution.

References

Sweeting M., Mander A., Sabin T. bcrm: Bayesian Continual Reassessment Method Designs for Phase I Dose-Finding Trials. Journal of Statistical Software (2013) 54: 1--26. http://www.jstatsoft.org/article/view/v054i13

See Also

bcrm, find.x

Examples

# NOT RUN {
prior.alpha <- list(1, 1, 1)
samples.alpha <- getprior(prior.alpha, 2000)
hist(samples.alpha)

# }