Used within the check_balance function to plot the standardized differences calculated
in the format of Love (2002).
plot_stand_diffs(sds, type)Either a ggplot object or a list of ggplot objects (if type is 'strata')
Standardized differences generated with get_stand_diffs.
One of the following, stating which standardized differences to plot:
standardized differences across the population
weighted average of the standardized differences within the strata (weighted by stratum size)
two facets displaying both the previous plots together
list of plots for the standardized differences within each stratum
Love, T. E. (2002), "Displaying covariate balance after adjustment for selection bias", Joint Statistical Meetings, yumpu.com/en/document/read/41664623.