<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
Ray,<br>
<br>
does this mean the the goal is still to propose NAPI as the official
way to write Nexus files? Developing and maintaining an API is a lot
of work. I wonder if a community like Nexus which has very limited
resources should take on more work. I remember issues in the past
with multi-threading and bugs which make the NAPI difficult to use.
Without adequate resources these problems will come back. <br>
<br>
Our preference is to use the HDF5 libraries directly even for Python
(h5py). <br>
<br>
Andy<br>
<br>
<div class="moz-cite-prefix">On 21/06/2015 22:23, Osborn, Raymond
wrote:<br>
</div>
<blockquote cite="mid:871134E1-76C7-4085-B630-386A7B686BAD@anl.gov"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
I had understood that there were plans to create a light version
of the NAPI, which was only dependent on HDF5. I am slightly
concerned about encouraging people only to use HDF5 directly,
because that makes it entirely dependent on them to ensure
compliance with the NeXus rules - e.g., by adding a group
attribute, NX_class, to each group.
<div class=""><br class="">
</div>
<div class="">Ironically, NAPI was written to remove much of the
complexity in writing files by having a reduced set of
functions. HDF5 is better written than HDF4 in this respect, but
the additional flexibility still makes it quite daunting to
learn. The NeXus API is a model of simplicity so a lightweight
API would still make sense.</div>
<div class=""><br class="">
</div>
<div class="">Ray</div>
<div class="">P.S. Of course, I would encourage people to use the
Python interface (<a moz-do-not-send="true"
href="http://nexpy.github.io/nexpy/" class="">http://nexpy.github.io/nexpy/</a>),
which is even simpler, and ensures compliant NXdata groups as
well.</div>
<div class="">
<div class=""><br class="">
<div>
<blockquote type="cite" class="">
<div class="">On Jun 21, 2015, at 1:04 PM, Tobias Richter
<<a moz-do-not-send="true"
href="mailto:Tobias.Richter@esss.se" class="">Tobias.Richter@esss.se</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">Hi Andy,<br class="">
<br class="">
The official policy just reflects the (perceived)
requirements of the community. Your thoughts are correct
NAPI is not recommended for new applications. And yes,
the manual hasn’t been updated in all areas to reflect
this. Please point us to the relevant sections you find
unclear. Someone reading the texts with fresh eyes can
really make a difference.<br class="">
<br class="">
Since we focus on HDF5 now, the NAPI backend abstraction
(supporting XML and HDF4 in addition) isn’t needed for
that. NAPI also provides nothing that would ensure files
follow the standard and very little that would at least
make conforming easier. So the only benefit is some
slight simplification of the hdf5 interface, which
denies some of the power of the underlying container
format.<br class="">
<br class="">
That being said, NAPI is not disappearing any time soon,
while people rely on it. We should drop support for
unused bindings though.<br class="">
<br class="">
In my view in the long run, some reference application
or tools would still be needed to be able to demonstrate
interoperability.
<br class="">
<br class="">
Regards,<br class="">
<br class="">
Tobias<br class="">
<br class="">
<br class="">
<blockquote type="cite" class="">On 21 Jun 2015, at
17:39, Andy Gotz <<a moz-do-not-send="true"
href="mailto:andy.gotz@esrf.fr" class="">andy.gotz@esrf.fr</a>>
wrote:<br class="">
<br class="">
Hi Eugen + Nexus community.<br class="">
<br class="">
I have a naive question : what is the status of the
NAPI? I thought it is being maintained only for legacy
applications and that it is not recommended for new
applications. But this is not clear from the manual.
In some places the reader gets the impression the NAPI
is the official API for accessing files conforming to
Nexus. In other places the opposite is stated and the
hdf5 API is considered as the right way to access
files.<br class="">
<br class="">
What is the official policy on the NAPI?<br class="">
<br class="">
Andy<br class="">
_______________________________________________<br
class="">
NeXus mailing list<br class="">
<a moz-do-not-send="true"
href="mailto:NeXus@nexusformat.org" class="">NeXus@nexusformat.org</a><br
class="">
<a class="moz-txt-link-freetext" href="http://lists.nexusformat.org/mailman/listinfo/nexus">http://lists.nexusformat.org/mailman/listinfo/nexus</a><br
class="">
</blockquote>
<br class="">
<br class="">
_______________________________________________<br
class="">
NeXus mailing list<br class="">
<a moz-do-not-send="true"
href="mailto:NeXus@nexusformat.org" class="">NeXus@nexusformat.org</a><br
class="">
<a class="moz-txt-link-freetext" href="http://lists.nexusformat.org/mailman/listinfo/nexus">http://lists.nexusformat.org/mailman/listinfo/nexus</a><br
class="">
</div>
</blockquote>
</div>
<br class="">
<div apple-content-edited="true" class="">-- <br class="">
Ray Osborn, Senior Scientist<br class="">
Materials Science Division<br class="">
Argonne National Laboratory<br class="">
Argonne, IL 60439, USA<br class="">
Phone: +1 (630) 252-9011<br class="">
Email: <a moz-do-not-send="true"
href="mailto:ROsborn@anl.gov" class="">ROsborn@anl.gov</a><br
class="">
<br class="">
</div>
<br class="">
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
NeXus mailing list
<a class="moz-txt-link-abbreviated" href="mailto:NeXus@nexusformat.org">NeXus@nexusformat.org</a>
<a class="moz-txt-link-freetext" href="http://lists.nexusformat.org/mailman/listinfo/nexus">http://lists.nexusformat.org/mailman/listinfo/nexus</a>
</pre>
</blockquote>
<br>
</body>
</html>