Tables contain a set of auxiliary information defining the data stored in the table. This information defines the general characteristics of the table, like physical size of the table, and also column related parameters like units, external format and column label. The auxiliary information is stored as MIDAS descriptors in the table file.
General information about the physical size of the table as well as the current number of columns and rows is obtained through the routine TBIGET (TCIGET).
Columns can be accessed by labels, which can be regarded as variable names at the command level. Labels are character strings (up to 16 characters) defined by the user when the column is created with TBCINI (TCCINI). Valid characters are letters, digits, and the underscore symbol (_). It is possible to read the label of a column using the routine TBLGET (TCLGET) and to update the column label with the routine TBLPUT (TCLPUT). Correspondence between label and column index is found with the routine TBLSER (TCLSER).
Each column in a table has an associated unit defined when the column is initialized. This unit can be read using the routine TBUGET (TCUGET) and can be updated with the routine TBUPUT (TCUPUT). The external format, used to display the information in a column, is controlled by the column format . In the current version, this format is defined in FORTRAN 77. The routine TBFGET (TCFGET) is used to read the format while the routine TBFPUT (TCFPUT) will update it.