plot_rhat: Plot Rhat convergence diagnostic

In tulpa: Templated Unified Library for Posterior Approximation in Bayesian Hierarchical Models

Plot Rhat convergence diagnostic

Description

Creates a visual display of Rhat values for all parameters, with color-coding to highlight convergence issues. Rhat values > 1.01 indicate potential convergence problems.

Usage

plot_rhat(fit, threshold = 1.01, pars = NULL)

Arguments

fit	A tulpa_fit object.
threshold	Rhat threshold for warnings (default: 1.01).
pars	Character vector of parameter names to include. If NULL (default), includes all main parameters (excludes high-dimensional RE/spatial).

Details

Color coding:

• Green: Rhat < 1.01 (converged)

• Yellow: 1.01 <= Rhat < 1.05 (borderline)

• Red: Rhat >= 1.05 (not converged)

Value

A ggplot object (if ggplot2 available) or base R plot (invisible).

See Also

plot_ess(), diagnostic_summary(), diagnostics()

Examples

# Diagnostic plots require a fitted tulpa model
# See tulpa() examples for fitting models


set.seed(123)
df <- data.frame(x = rnorm(60))
df$y <- rpois(60, exp(0.5 + 0.3 * df$x))
fit <- tulpa(y ~ x, data = df, family = "poisson", mode = "hmc",
             control = list(n_iter = 500L, warmup = 250L, n_chains = 2L,
                            seed = 1L))
plot_rhat(fit)

tulpa documentation built on Oct. 19, 2026, 5:09 p.m.