Correlation matrix of estimated parameters

Description

Converts the parameter covariance matrix (already stored on the fit object) into a correlation matrix, making off-diagonal structure immediately visible. A correlation close to \(\pm 1\) between two parameters flags a structural identifiability problem in the model.

Usage

ferx_cor_matrix(fit)

Arguments

fit: A ferx_fit object returned by [ferx_fit](ferx_fit.qmd).

[ferx_estimates](ferx_estimates.qmd) for SEs and diagnostics: [check_diagnostics](check_diagnostics.qmd)(), [ferx_cov_screen](ferx_cov_screen.qmd)(), [ferx_estimates](ferx_estimates.qmd)(), [ferx_eta_cov](ferx_eta_cov.qmd)(), [ferx_plot_trace](ferx_plot_trace.qmd)(), [ferx_runlog_iters](ferx_runlog_iters.qmd)(), [ferx_trace](ferx_trace.qmd)(), [ferx_warnings](ferx_warnings.qmd)(), [summary.ferx_fit](summary.ferx_fit.qmd)()

Concept

diagnostics

Value

Named correlation matrix (invisibly). Printed to the console.

Examples

ex  <- ferx_example("warfarin")
fit <- ferx_fit(ex$model, ex$data, method = "gn", covariance = TRUE)
if (!is.null(fit$cov_matrix)) ferx_cor_matrix(fit)