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Design of the GILDAS Data Format

The Gildas Data Format and its associated API are based on concept of memory copy. In a program, access to a GDF file is done by reading into memory the file header and part or all of the file data. These informations are stored in a Fortran derived type named gildas. This derived type is described in Appendix A.

It is essentially build on 5 items:

While numbers are always represented in the current hardware format in the RAM memory (e.g., big-endian or little-endian), they may be stored in a different way on the disk. The API (available is the so-called GIO library) handles the data format conversion (in the data and in the header) transparently. The data format, although described here, is not intended to be used directly, but only through the API.


next up previous contents
Next: GDF Images Up: IRAM Memo 2012-? Preparing Previous: Introduction   Contents
Gildas manager 2015-03-19