[NeXus-tech] NXimpatient

[Tobias.Richter at diamond.ac.uk]

Hi,

It took some time, but now I've had a closer look at the document.

Of the 23 pages it generates 11 are either empty or contain meta information like title and tables of contents. If we didn't attempt laying it out as a book (which we agree it does not try to be) we'd be near 10 pages and a TOC wouldn't even be required any more.

Section 5.1 (What goes into a NeXus File) is too late to explain the structure. Reading a file (Chapter 4) cannot be sensibly done before you know what is where (hence I disagree with the statement at the beginning of chapter 5). And chapter 2 already tells half the story anyway. That's where I'd move 5.1 into.

Section 5.3 does not work for me. The file system analogy works when introducing hdf5 groups and datasets, but struggles with attributes (although many file systems support them). But presenting this at the very end, after the NeXus classes and structure have been introduced and are now ignored, confuses me.

One of the main requests from Chris and friends was simple instructions how to write a NeXus file outside the API. What are the elements the API and tools look for. How are they formatted, what NeXus version to I claim, what is the target attribute on links used for? 
As we are only writing using the API and not even generating links we are not really addressing that in this document. 

I believe Pete J has put some h5dumps for example files into the manual. That should be directly linked.

Freddie already made the point that the C examples are not too helpful for the impatient. On the 12 pages of content we have examples in C/NAPI, C/HDF5, python/NAPI, python/h5py, and MATLAB. I'd limit that to C/NAPI and python h5py and refer to the full manual for others. It is enough to get the idea of both the NAPI and non-NAPI approach while being reasonably concise. If you program C/HDF5 and you are looking at the h5py code you will know where to throw in your variable declarations, a bunch of close calls and a few mallocs for good measure. I intentionally left out the 'free' calls, as our example doesn't have any either.

If there is some consensus I'd be happy to make the suggested changes. I'd see how far I get with the open problems.

Regards,

Tobias
________________________________________
From: nexus-tech-bounces at nexusformat.org [nexus-tech-bounces at nexusformat.org] on behalf of Pete Jemian [prjemian at gmail.com]
Sent: 22 November 2011 16:29
To: nexus-tech at nexusformat.org
Subject: Re: [NeXus-tech] NXimpatient

On reviewing the NXimpatient.rst document, there are several example
NeXus data files in the example code.

Can someone supply (email to me, commit to svn, identify a URL, ...)
copies of these files?  One is already found.

NXfile.h5

sn2013287.nxs

powder.h5

lrcs3701.nxs
        http://svn.nexusformat.org/definitions/exampledata/IPNS/LRMECS/lrcs3701.nxs

NXfile.nxs
_______________________________________________
NeXus-tech mailing list
NeXus-tech at nexusformat.org
http://lists.nexusformat.org/mailman/listinfo/nexus-tech

-- 
This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. 
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom