The subid_unique column in processed_data/03_data_trial_main.csv is constructed by concatenating lab, a colon, and subid. It contains missing values despite the fact that there are no missing values in lab and subid. The missing value positions in subid_unique could, and probably should, be replaced by the appropriate strings.
The
subid_uniquecolumn inprocessed_data/03_data_trial_main.csvis constructed by concatenatinglab, a colon, andsubid. It contains missing values despite the fact that there are no missing values inlabandsubid. The missing value positions insubid_uniquecould, and probably should, be replaced by the appropriate strings.