calculate_geometric_average
                        Calculate the geometric average of a series of
                        values
calculate_hedonic_index
                        Calculate index based on specified method
                        (Fisher, Laspeyres, Paasche, HMTS, Time Dummy,
                        Rolling Time Dummy)
calculate_price_index   Calculate Price Index (Deprecated)
calculate_regression_diagnostics
                        Calculate regression diagnostics by period
data_constraxion        A real estate example dataframe
plot_price_index        Plot index output from calculate_hedonic_index
plot_regression_diagnostics
                        Plot diagnostics output from
                        calculate_regression_diagnostics as a
                        multi-panel grid (base R)
