Starlink User Note 33.12
R.F. Warren-Smith & D.S. Berry
30st April 2020
Routines for Accessing the
Extensible N-Dimensional Data Format
The Extensible N-Dimensional Data Format (NDF) is a format for storing bulk data in the form of N-dimensional arrays of numbers. It is typically used for storing spectra, images and similar datasets with higher dimensionality. The NDF format is based on the Hierarchical Data System HDS (SUN/92) and is extensible; not only does it provide a comprehensive set of standard ancillary items to describe the data, it can also be extended indefinitely to handle additional user-defined information of any type.
This document describes the routines provided for accessing NDF data objects. It also discusses all the important NDF concepts and includes a selection of simple example applications. The majority of the text describes the Fortran 77 interface for the NDF library. The C interface is described briefly in an appendix.