Specify a gamma prior for a positive parameter.
Usage
prior_gamma(shape = 2, rate = 0.1)
Arguments
- shape
Shape parameter (alpha). Must be positive.
- rate
Rate parameter (beta). Must be positive.
Value
A ratiod_prior object
Details
Mean = shape/rate, Variance = shape/rate^2.
Examples
prior_gamma(2, 0.1) # Mean = 20, weakly informative
#> Gamma(2.00, 0.10) [mean = 20.00]
prior_gamma(1, 1) # Exponential(1)
#> Gamma(1.00, 1.00) [mean = 1.00]