a_map_var: Get the column name in the source data file.
In olssol/ADTool: Alzheimer Disease Data Tools

Since the column names in tables may vary, it could be modified by using a costomized column names dictionary. The format can refer to the appended dictionary.

a_map_var(
  src_type = c("BIOCARD", "NACC", "ADNI"),
  tbl_code,
  col_name,
  dict_src_tables = NULL
)

`src_type`	A string indicating the source of data. Options include "BIOCARD", "NACC" and "ADNI"
`col_name`	A string indicating a column name in the source data file.
`dict_src_tables`	A dictionary file for the parameters. The default dictionary is appended in the package. Since the parameters in tables may vary, it could be modified by using a costomized parameter dictionary. The format can refer to the appended dictionary. See `dict_src_tables` for more details.