Internal Function: Called within the metadata_map function.
Searches for previous OUTPUT files in the output_dir, that match the dataset
name.
If files exist, it removes duplicates and autos, and stores the rest of the
table variables in a dataframe.
Value
It returns a list of 2: df_prev_exist (a boolean) and df_prev (NULL or populated with table variables to copy)
See also
Other metadata_map_internal:
data_load()
,
empty_count()
,
empty_plot()
,
end_plot()
,
user_categorisation()
,
user_categorisation_loop()