qbrms (version 1.0.1)

visualise_prior: Visualise Prior Distributions

Description

Create visual representations of prior distributions to aid in prior specification and sensitivity analysis.

Usage

visualise_prior(
  prior,
  parameter = NULL,
  xlim = NULL,
  add_reference = TRUE,
  samples = 10000
)

Value

A ggplot object showing the prior distribution(s)

Arguments

prior

Prior specification in qbrms format, or a list of prior specifications to compare

parameter

Character string specifying which parameter to visualise (e.g., "b", "sd", "sigma"). If NULL, visualises all priors.

xlim

Numeric vector of length 2 specifying x-axis limits. If NULL, automatically determined.

add_reference

Logical; if TRUE, adds reference distributions for comparison (default: TRUE)

samples

Number of samples to draw for visualisation (default: 10000)

Details

This function helps users:

• Visualise the implications of their prior choices

• Compare different prior specifications

• Identify overly informative or vague priors

• Understand prior-data conflict potential

Supported prior distributions include:

• Normal: normal(mean, sd)

• Student t: student_t(df, mean, scale)

• Cauchy: cauchy(location, scale)

• Exponential: exponential(rate)

• Gamma: gamma(shape, rate)

• Uniform: uniform(lower, upper)

Examples

if (FALSE) {
# Visualise a single prior
prior <- prior(normal(0, 10), class = "b")
visualise_prior(prior)

# Compare different priors
prior_list <- list(
  "Weak" = prior(normal(0, 10), class = "b"),
  "Medium" = prior(normal(0, 5), class = "b"),
  "Strong" = prior(normal(0, 1), class = "b")
)
visualise_prior(prior_list)

# Visualise with custom limits
visualise_prior(prior, xlim = c(-20, 20))
}