beta.select: Selection of Beta Prior Given Knowledge of Two Quantiles

In LearnBayes: Functions for Learning Bayesian Inference

Description

Finds the shape parameters of a beta density that matches knowledge of two quantiles of the distribution.

Usage

beta.select(quantile1, quantile2)

Arguments

quantile1	list with components p, the value of the first probability, and x, the value of the first quantile
quantile2	list with components p, the value of the second probability, and x, the value of the second quantile

Value

vector of shape parameters of the matching beta distribution

Author(s)

Jim Albert

Examples

# person believes the median of the prior is 0.25 
# and the 90th percentile of the prior is 0.45
quantile1=list(p=.5,x=0.25)
quantile2=list(p=.9,x=0.45)
beta.select(quantile1,quantile2)

Example output

[1] 2.67 7.37

LearnBayes documentation built on May 1, 2019, 7:03 p.m.