Filter QDEC long table for subjects.
qdec.table.filter(qdec_file, subjects_list, output_qdec_file = NULL)
the data.frame containing the subset of subjects from the original QDEC file.
the source QDEC table
the subjects to extract from the QDEC file
optional character string, a file name to which to write the resulting, filtered table. If not given, no file is created.