stickplot_pairs: Draw a pairs-like plot of covariance sticks
In ashiklom/mvtraits: Fit multivariate models to partially missing trait data

Draw a pairs-like plot of covariance sticks

stickplot_pairs(mu_global_lower, Sigma_global_lower, mu_group_lower,
  Sigma_group_lower, vars_lower, group_names, vars_label = vars_lower,
  unlog_axes = FALSE, mu_global_upper = mu_global_lower,
  Sigma_global_upper = Sigma_global_lower,
  mu_group_upper = mu_group_lower,
  Sigma_group_upper = Sigma_group_lower, vars_upper = vars_lower,
  par_plot = list(), par_legplot = list(), par_legend = list(),
  par_label = list(), reorder_legend = FALSE,
  screen_split = rbind(c(0, 1, 0.2, 1), c(0, 1, 0, 0.2)), ...)

`mu_global_lower`	List of global means for lower triangle
`Sigma_global_lower`	List of global variance-covariance matrices for lower triangle
`mu_group_lower`	List of group means for lower triangle
`Sigma_group_lower`	List of group variance-covariance matrices for lower triangle
`vars_lower`	Names of variables for lower triangle
`group_names`	Names of each group. Must match order in `mu_group` and `Sigma_group`.
`vars_label`	Labels for diagnoals
`unlog_axes`	If TRUE, apply `10^x` transformation to axes
`mu_global_upper`	List of global means for upper triangle
`Sigma_global_upper`	List of global variance-covariance matrices for upper triangle
`mu_group_upper`	List of group means for upper triangle
`Sigma_group_upper`	List of group variance-covariance matrices for upper triangle
`vars_upper`	Names of variables for upper triangle
`par_plot`	List of graphical parameters for plot
`par_legplot`	List of graphical parameters for legend plot box
`par_legend`	List of options passed directly to `legend` function
`par_label`	List of graphical parameters for diagonal labels
`reorder_legend`	If `TRUE`, put last drawn layer first in legend.
`screen_split`	`figs` argument for `graphics::split_screen()` for plot-legend split.
`...`	Additional parameters to `prep_stickplot()`