(CGNS Documentation Home Page)
(Steering Committee Charter)
(Overview and Entry-Level Document)
(A User's Guide to CGNS)
(Standard Interface Data Structures)
(SIDS-to-ADF File Mapping Manual)
(SIDS-to-HDF File Mapping Manual)
(ADF User's Guide)
(CGNS Tools and Utilities)
CGNS Steering Committee
28 September 2004
11:00 AM Eastern Time
- The meeting was called to order at 11:05 AM. There were
14 attendees, listed below.
- The minutes of the 30 June 2004
meeting were approved as posted on the web site.
- Status of previous action items:
- Wedan will formally archive old versions of software on
- not done yet - action item carries
- Alonso and Hann will send Wedan some of their examples of CGNS
files and programs that write/read them, and Wedan will post them.
- example CGNS files sent & posted; van der Weide will look
for example codes to send to Wedan to post also
- Hauser will check into parallel issues regarding
- in process: reading OK; investigating writing now (for
- Rumsey to send e-mail to CGNStalk & Shih regarding 8 units
- done - only response involved sound units (dB); see below
- Rumsey to send Poinot's AIAA paper to Towne to post.
- Rumsey to work with Tom Shih of CoS to draft letter from AIAA
to software companies urging active support of CGNS.
- done (sent to AIAA)
- suggestion to further advertise by handing out CGNS
material at AIAA meeting in exhibit hall - Rumsey and
Edwards will look into this
- Rumsey to check with Towne regarding posting documentation to
- Rumsey to discuss (during this telecon) the possibility of
holding a CGNS User's meeting in summer 2005, in conjunction with
the AIAA meeting.
- Rumsey to discuss (during this telecon) the possible date of
summer 2005 as a goal for switching over to HDF-5.
- Status of open items from prior meetings
- It is not yet known whether issue of links causing slowdown in
files with thousands of blocks will be as big a problem with
HDF-5. See 7a.
- ISO status/discussion (Cosner, in absentia):
- Boeing does not appear willing to resume funding of AP 237
soon (no funding since 1/1/03).
- At time of cancellation, fluid dynamics standard was 80-90%
- The ISO-STEP category of "Engineering Analysis Data" (for
which AP 237 was one component) is led by Keith Hunter
of Lockheed-Martin, Ft. Worth TX. He plans to integrate
fluid dynamics standard with the existing AP 209 standard
for finite-element solid mechanics (many underlying data
structures are functionally the same). It is expected that
the CFD-related structures derived from CGNS will be preserved
in the process.
- This go-forward plan is based on the assumption that Boeing
will not resume participation in this effort. (Note: Cosner
is now in a new position in Boeing, so even if Boeing funding
is restored, he will not be able to participate, except in
initial stages of re-launching the Boeing engagement.)
- Documentation issues and CGNStalk issues (Towne):
- Discussion of putting documentation on SourceForge or not
- Towne creates and posts both PDF and HTML - may lose this
generality if post to SourceForge (it is not straightforward
to do both automatically)
- After discussion, decided that Towne will post LaTeX
documents on website. Anyone interested in modifying the
documentation can download these and pass back to Towne, who
will create new PDF and HTML.
- Decision also made to put old versions of documentation
on SourceForge in tar files along with old versions of
CGNS software. Towne will send Wedan old versions of
documentation. Wedan will also look for version 1.x
documentation and will post on Sourceforge along with that
- Status of V2.3 becoming revised AIAA recommended practice
- AIAA has put the SIDS out for public comment - Towne will
e-mail Craig Day at AIAA to find out status.
- Is there a need to add & define "SoundIntensityDB"
and others from acoustics as a data name identifier?
- Rumsey will e-mail Bussoletti to ask him for definitions,
if he would like them implemented. It should be easy to
implement, because it is simply a definition in the SIDS.
- Rumsey asked about hitting "reply" when answering a CGNSTalk
e-mail. By default the reply goes to sender only and not
CGNSTalk. Towne will check to see if the settings can be
changed so replys automatically go to CGNSTalk.
- Software status/discussion (Wedan):
- Status of slowdown when writing files with thousands of
blocks, using links
- question as to whether this will still be a major issue
- Van der Weide will try out the HDF-5 version of CGNS on
his test case, using links, and will report back
- Need for cg_axisym_query call?
- there was an error that has been fixed, so there should
no longer be a problem with this using existing calls
- this and many other small bug fixes have been made -
Wedan will make another 2.3.x release and will announce it
- Can we have API sort BCs and Connectivity alphanumerically
- a lot of discussion on this; if everything done
alphanumerically, it will help with regard to HDF-5 (make it
more efficient), but if a user is expecting creation order,
then there would be problems
- most participants in the discussion seemed to feel that
doing alphanumeric sorting would be desirable, but no firm
decision made yet (this will be added to list of open items)
- Wedan mentioned that the CGNS check routine now checks all
syntax for V2.3.
- HDF-5 status/discussion (Hauser, Poinot):
- Held discussion on possible official switchover date to
HDF-5 in Summer 2005. It was felt that a Beta version (including
documentation) should be released at least 6 months prior to the
- In looking at the "to-do" list, many people
felt that the entire list wasn't really necessary
to complete prior to beta release. In other words, many
of the items could be done later. Thus, January 2005 may
even be a realistic date for releasing and announcing a Beta
version. We would need to decide for sure on this issue by the
- Three key items on the "to do" list seem to be:
- completing the documentation (especially SIDS-to-HDF5
mapping document) - Poinot agreed to work on this
- deciding how to perform automatic (or not) updating
of ADF-type CGNS files to HDF5-type; this is important for
backward compatibility, since many users would want the
conversion to occur automatically and transparently, but it
was also discussed that some users might want to preserve the
old ADF-type file as is - we need to give more thought to
this, and discuss again at the next telecon
- issue of creation order
- Extensions status/discussion (Edwards):
- Intelligent Light (IL) is completing 6 extensions, as part of
- EM part still needs testing - Michal will check with
other Boeing people to see if they can do this soon
- There are still some minor issues with partial
read/write: Wall will look into possibility of filling in
unwritten portions of array with NaN's (will this work on
- There is also a minor fix needed (add
- The extensions will eventually be implemented as Version 2.4
- Other issues:
- Need for developing certification process was not discussed,
but remains an issue. This will be added to list of open items.
- Discussion of holding a possible "CGNS User's meeting" was
tabled; it is subject to decision on release date of V3.0.
- Poinot's CGNS compiler is not ready for release yet, but
should be finished by January 2005 in time for his paper
presentation at the AIAA meeting in Reno.
- Rumsey mentioned that his 2-year term as chairperson will
expire in January 2005. At that time (Reno meeting) we need to
hold a chairperson election. Anyone interested in filling this
position should contact Rumsey or Bush. Primary responsibilities
include (1) organizing and leading regular telecons and meetings,
(2) processing the minutes, (3) helping to lead and keep track
of the various activities and directions of the CGNS effort, and
(4) working to promote CGNS and give it greater visibility. The
chairperson should be able to attend one face-to-face CGNS meeting
per year (typically this has been the AIAA meeting in Reno). Also,
it is helpful for the chairperson to maintain contact with the
AIAA's CoS (Committee on Standards), which is our "parent"
committee. The CoS also holds meetings at AIAA conferences.
- Next telecon will be sometime in November 2004.
- Meeting was adjourned at 12:30 PM.
- Summary of action items:
- Wedan will formally archive old versions of software, along
with corresponding documentation (including 1.x versions if they
can be found), on SourceForge.
- Van der Weide will look for examples of CGNS read/write
programs, and will send to Wedan for posting.
- Hauser will continue to check into parallel issues regarding
- Rumsey and Edwards to look into possibility to advertise CGNS
by handing out CGNS material at AIAA meeting in exhibit hall.
- Towne will post LaTeX documents on documentation website.
- Towne will send Wedan old versions of documentation for
posting on SourceForge.
- Towne will e-mail Craig Day at AIAA to find out status of
latest SIDS as AIAA recommended practice document.
- Rumsey will e-mail Bussoletti to ask him for definitions of
- Towne will check to see if the settings in CGNSTalk can be
changed so replys automatically go to CGNSTalk.
- Van der Weide will try out the HDF-5 version of CGNS on his
test case, using links, and will report back.
- Wedan will make another 2.3.x release and will announce it
- Poinot will work on completing SIDS-to-HDF5 documentation, in
preparation for the Beta release of V3.0.
- Michal will check with other Boeing people to see if they can
test EM extension soon.
- Wall will look into possibility of filling in unwritten
portions of array with NaN's for partial read/write extension, and
will work with Wedan to prepare all extensions for release.
- Summary of open items from prior meetings (these are different from
action items, in that they are open or unresolved issues that we
want to keep track of, but there are no specific actions required
of anyone at this point in time):
- Issue of links causing slowdown (perhaps can modify open call
so it does not follow links).
- With next major release, eliminate the
Pointlist/Range + CellCenter possibility
(and thus remove the need for GridLocation under
BC_t). Next major release of API will need to
automatically make the alteration (transparent to the
user). Documentation (SIDS, User's Guide, other?) will need to
- Resolve HDF-5 "to-do" list.
- Issue of 8 units - need consistency between DimensionalUnits
- Eventually resolve any differences between SIDS and ISO/STEP.
- Question of need (or preference) to have alphanumeric sorting
of everything (like is currently done for zones)
- Need for developing certification process (official test for
||Pratt & Whitney
||Boeing - Rocketdyne
||Boeing - Rocketdyne
||Utah State University
||Boeing - St. Louis
||Edwin Van der Weide||
Tentative to-do list prior to HDF-5 switchover
- Complete and test parallel implementation
- Complete and test API capability to automatically detect and switch
between ADF and HDF-5 (transparent to user?)
- Assess/minimize impact on software vendors using CGNS
- Make changes recommended by HDF-5 to improve usability with HDF-5
(e.g., character strings as opposed to character arrays)
- HDF-5 must fix "creation tracking"
- Assess compression capability of HDF-5
- Create SIDS-to-HDF-5 documentation (Poinot?)
- CGNS configure scripts will need to be modified to check for
availability of appropriate HDF-5 libraries.
- Possibly add flag-based options when opening CGNS files. For
example: "follow links" vs. "don't follow links"; "use ADF" vs. "use
HDF-5"; "translate file automatically" vs. "leave the file as-is";
"compress" vs. "don't compress".
- Look into eliminating need for ID's from MLL