1.5. Verification and validation of files

The intent of verification and validation of files is to ensure, in an unbiased way, that a given file conforms to the relevant specifications. Validation does not check that the data content of the file is sensible; this requires scientific interpretation based on the technique.

Validation is useful to anyone who manipulates or modifies the contents of NeXus files. This includes scientists/users, instrument staff, software developers, and those who might mine the files for metadata. First, the scientist or user of the data must be certain that the information in a file can be located reliably. The instrument staff or software developer must be confident the information they have written to the file has been located and formatted properly. At some time, the content of the NeXus file may contribute to a larger body of work such as a metadata catalog for a scientific instrument, a laboratory, or even an entire user facility.

1.5.1. nxvalidate

The cnxvalidate utility [1], new in 2016, is available for testing. Refer to the GitHub location for the most recent information.

This utility only works on HDF5 files and is aimed to be faster, simpler, more portable and robust than previous programmes for NeXus file validation.

[1]	cnxvalidate: from https://github.com/nexusformat/cnxvalidate

1.5.2. punx

Python Utilities for NeXus HDF5 files

punx can validate both NXDL files and NeXus HDF5 data files, as well as print the structure of any HDF5 file, even non-NeXus files.

NOTE: project is under initial construction, not yet released for public use, but is useful in its present form (version 0.0.9).

See the program documentation for more details: https://punx.readthedocs.io