ggplot_na_distribution
                        Line Plot to Visualize the Distribution of
                        Missing Values
ggplot_na_distribution2
                        Stacked Bar Plot to Visualize Missing Values
                        per Time Interval
ggplot_na_gapsize       Bar Plot to Visualize Occurrences of Different
                        NA Gap Sizes
ggplot_na_gapsize2      Bubble Plot to Visualize Total NA Count of NA
                        gap sizes
ggplot_na_imputations   Line Plot to Visualize Imputed Values
na_interpolation        Missing Value Imputation by Interpolation
na_kalman               Missing Value Imputation by Kalman Smoothing
                        and State Space Models
na_locf                 Missing Value Imputation by Last Observation
                        Carried Forward
na_ma                   Missing Value Imputation by Weighted Moving
                        Average
na_mean                 Missing Value Imputation by Mean Value
na_random               Missing Value Imputation by Random Sample
na_remove               Remove Missing Values
na_replace              Replace Missing Values by a Defined Value
na_seadec               Seasonally Decomposed Missing Value Imputation
na_seasplit             Seasonally Splitted Missing Value Imputation
statsNA                 Print Statistics about Missing Values
tsAirgap                Time series of monthly airline passengers (with
                        NAs)
tsAirgapComplete        Time series of monthly airline passengers
                        (complete)
tsHeating               Time series of a heating systems supply
                        temperature (with NAs)
tsHeatingComplete       Time series of a heating systems supply
                        temperature (complete)
tsNH4                   Time series of NH4 concentration in a
                        wastewater system (with NAs)
tsNH4Complete           Time series of NH4 concentration in a
                        wastewater system (complete)
