center_lm               Center variables in fitted regression models
gscale                  Scale and/or center regression inputs,
                        including from survey designs, by dividing by 2
                        SD
interact_plot           Plot interaction effects in regression models
j_summ                  Regression summaries with options
johnson_neyman          Calculate Johnson-Neyman intervals for 2-way
                        interactions
probe_interaction       Probe interaction effects via simple slopes and
                        plotting
scale_lm                Scale variables in fitted regression models
sim_slopes              Perform a simple slopes analysis
svycor                  Calculate Pearson correlations with complex
                        survey data
svysd                   Calculate standard deviations with complex
                        survey data
theme_apa               Format ggplot2 figures in APA style
wgttest                 Test whether sampling weights are needed
