Hi,
I'm writing a module to import fixed mesh refinement datasets from HDF5 data
files which were created using the AMR writer API of the FlexIO library
(http://zeus.ncsa.uiuc.edu/~jshalf/FlexIO/).
Each dataset represents a regular-shaped patch; multiple patches of different
refinement levels can be nested in a grid hierarchy.
My import module reads a grid hierarchy as a multigrid group, with the
individual patches being members of that group. Each patch is created as a
field with regular positions and connections.
For nested patches, I then invalidate all the positions on the coarser and
finer grid respectively where they overlap at the boundaries. I do this
explicitely in the code by looping over all positions and use DXSetElement-
Invalid() to mark the overlapping ones.
Is there an easier way to do that ? All patches have a positions component,
so can I do some sort of set operation ("mark the union of the two sets of
positions as invalid") ?
When I'm done with invalidating all the overlapping positions I update the
connections for each patch by calling DXInvalidateConnections(). Is that
enough, or do I have to call DXChangedComponentStructure() also, eg. in order
to get the bbox right ?
The problem I'm seeing in the final visualization of my 3D FMR datasets (eg.
as isosurfaces) is that sometimes the Image module returns an error "Bad
parameter: camera causes numerical overflow". This happens only occasionally
on the same dataset - just rotating the thing might then work fine.
I wonder if this has to do with a bug in my code which invalidates the over-
lapping positions (I've never seen such an error with this feature turned
off). Or is this potentially related to a bug in the DX code which deals
with invalid positions (see
http://opendx.npaci.edu/mail/opendx-users/2003.08/msg00040.html) ?
Thanks in advance for any help !
Thomas.
--
=========================================================================
Thomas Radke
Max-Planck-Institute for Gravitational Physics, Albert-Einstein-Institute
Am Muehlenberg 1, 14476 Golm, Germany
fon +49 331 567-7329 fax +49 331 567-7298 http://www.aei.mpg.de/~tradke
=========================================================================
