all_na                  function to test if an entire column is NA
mbm_resample            Dataframe resample function
nc                      function to convert to character then numeric
num_test                function to test is the values in a column
                        should be numeric
plr_6k_model            6k Method for PLR Determination
plr_bootstrap_output    Bootstrap: Resampling from individual Models
plr_bootstrap_output_from_results
                        Bootstrap: Resample from individual Models
plr_bootstrap_uncertainty
                        Bootstrap: Resampling data going into each
                        Model
plr_build_var_list      Build a Custom Variable List
plr_cleaning            Basic Data Cleaning
plr_convert_columns     Fix Column Typings
plr_decomposition       Decompose Seasonality from Data
plr_kmeans_test         Statistical k-means Test
plr_pvusa_model         PVUSA Method for PLR Determination
plr_remove_outliers     Filter outliers from Power Predicted Data
plr_saturation_removal
                        Removing Saturated Data
plr_seg_extract         Segmented linear PLR extraction function
plr_var                 PLR linear model uncertainty
plr_variable_check      Define Standard Variable Names
plr_weighted_regression
                        Weighted Regression
plr_xbx_model           XbX Method for PLR Determination
plr_xbx_utc_model       UTC Method for PLR Determination
plr_yoy_regression      Year-on-Year Regression
test_df                 DOE RTC Sample PV System Data
