[Paraview] RAM friendly file format?

[SamuelKey]

Noel,

1) Your second question -- "And as a second question, which one 
would be the recommended format for generation using fortran90?"

I have had considerable success using PV's EnSight reader. I write
the results to an EnSight c binary format using Fortran-90, see 
attached file. (You may obtain the EnSight User's Manual from 
http://www.ensight.com/ensight80docs/Manuals/ , see Chapter 11) 

The attached gzip'ed Fortran file that I use to write C-binary 
(unblocked byte stream) formatted files for use with  PV via 
PV's EnSight reader is compiled with HP/Compaq/Digital
Visual Fortran on Win2K & WinXP64

The OPEN statements are for use with HP/Compaq/Digital
Visual Fortran (some non-standard key-words). I have versions
of this for G95's (http://www.g95.org) and PathScale's Fortran
compilers on Linux x86-32/64.

It is 3,500 lines of Fortran, but then I am trying to put out a time=0
mesh file followed by time sequenced data, blocked for large
data sets (to avoid output buffer overflows), subdivided into parts 
based on materials, and a medium number of point & cell items. 
Not to mention 7 or so cell geometries along with extraction routines  
that move data from the program's storage directly into the write 
statement buffers.

It may be too complex to help you at this stage, but it is all there.


2) Your first question -- "Is there any  particular file format 
(xml/ensight etc) that is designed to use less  system ram when 
visualising the models, for the same model detail?"

I started using PV with vtk-XML all ASCII formatted input. Yes,
the files are large in both size and number, but once the data is 
read in, it is stored in binary. It does not matter (or should not) 
if the data came from binary or ASCII  files. (The vtk-XML legacy 
ASCII format reads in amazingly fast.)  How much RAM is used 
by PV to store the data I am sure is mildly dependent on the 
reader, that is, the EnSight binary reader can have a richer view 
of the data and thus has to have some additional info structures 
to track this. I am sure the storage required is lost in the noise.

The PV *.pvd file is an excellent way to break your model into
rational pieces (each of which must be a "displayable" data set).

I have had crashing problems with large data sets in PV. I have
tracked it down to a 2GB limit in Win2K & WinXP64 for an
application's memory foot print (an application's memory foot
print is managed in terms of pages -- it does not matter whether
it is located in RAM or the page file or in any mix in between. In
PV, of course, you don't want any of PV's memory swapped out to 
the pagefile.)  MS Windows besides physically fragmenting the 
pagefile on the HD, is perfectly capable of fragmenting the pagefile 
internally. Sooner or later it will come crashing down. (I combat this 
- as best I can - by putting the pagefile in its own very large disk 
partition as a single very large, contiguous block that fills the 
dedicated partition.)

I have the same problems with this data set (840K 4-node
tetrahedrons) in PV on AMD64 Suse Linux 9.3. It happens
when I try to animate 101 time steps. If I am very careful to
read in just the data I need and limit the number of iso-surfaces,
I can get the animation completed and watch it run -- an extremely
helpful capability.

Sam Key


----- Original Message ----- 
From: <noelieboy at online.ie>
To: <paraview at paraview.org>
Sent: Friday, February 03, 2006 2:30 AM
Subject: [Paraview] RAM friendly file format?


> Hi there,
> I am currently writing legacy VTK files of a surface made 
> unstructured_grid using fortran 90, and look at them  in Paraview that 
> is installed on my desktop PC (2GB RAM). I now want to start viewing 
> large models and using the current method the files are getting big and 
> also paraview crashes (i assume due to lack of RAM). Is there any 
> particular file format (xml/ensight etc) that is designed to use less 
> system ram when visualising the models, for the same model detail? And 
> as a second question, which one would be the recommended format for 
> generation using fortran90 ?
> 
> 
> _______________________________________________
> ParaView mailing list
> ParaView at paraview.org
> http://www.paraview.org/mailman/listinfo/paraview
> 
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