add_3d_surface          Add 3D regression surface to a plot_ly object
add_direction           A flexible function to add a line of predicted
                        effects to the plotly surface with optional
                        confidence intervals.
add_jitter              Jitter scattercloud points
add_marginals           Add 3d marginal effects to a plot_ly object
cali_counties           County level voting and demographics data for
                        California counties.
county_data             County level voting and demographics data.
create_surface_data     Create data frame used to plot a surface of
                        predicted y values
create_y_estimates      Create predicted y values from a data frame of
                        x values.
hair_data               Simulated hair length data
