plot_all_joint_marginals {BEDASSLE}

Plots the joint marginals for all parameter pairs

Description

For each sampled MCMC generation, the values estimated for a pair of parameters are logged and plotted against one another. Points are color coded by when in the analysis they were sampled, so that users can visually assess mixing. A joint marginal plot is generated for all combinations of parameters, excluding the phi parameters estimated in the beta-binomial model.

Usage

plot_all_joint_marginals(MCMC.output, percent.burnin = 0, thinning = 1)

Arguments

MCMC.output

The standard MCMC output file generated from a BEDASSLE run.

percent.burnin

The percent of the sampled MCMC generations to be discarded as "burn-in." If the MCMC is run for 1,000,000 generations, and sampled every 1,000 generations, there will be 1,000 sampled generations. A percent.burnin of 20 will discard the first 200 sampled parameter values from that sample.

thinning

The multiple by which the sampled MCMC generations are thinned. A thinning of 5 will sample every 5th MCMC generation.

Details

Visualizations of the joint marginal distributions allow users to (1) assess how well the MCMC is mixing, and (2) potentially diagnose instances of non-identifiability in the model. Strong linear trends in the joint marginal, or visible "ridges" in the likelihood surface, may be indicative of parameter non-identifiability, in which multiple combinations of values of these two parameters provide equally reasonable fits to the data.

Author(s)

Gideon Bradburd