APL functions for interactive data analysis: Preparation of data files

APL functions to support preparation of data files are presented: a function to manage the entry of raw data, functions to display the entered data in formats convenient for checking, a function to support correction of errors, a function to organize the data into tables and file them, and a user interface function that provides menu selection of the data preparation functions. General-purpose support functions to assist in file use and in menu selection are also provided.