[petsc-users] binary writing to tecplot

[Matthew Knepley]

On Tue, Nov 22, 2011 at 7:53 AM, Benjamin Sanderse <B.Sanderse at cwi.nl>wrote:

> Thanks for the quick reply.
> Tecplot is able to read HDF5 files according to the possible types listed
> in its dataloader, so that seems like an interesting option. But where do I
> find Petsc documentation on writing HDF5 files? Is this in the development
> version?
> By the way, I am using structured Cartesian grids, and all operations such
> as interpolation and differentiation are carried out as matrix-vector
> products, which also include boundary conditions. I am not using DAs at the
> moment, would it be better to use those?
>

DMDAs only manage a very special data layout on a Cartesian grid. It can
store a given number of dofs at each vertex, If you fit that
scenario, definitely use them.

   Matt


> Op 22 nov 2011, om 14:04 heeft Jed Brown het volgende geschreven:
>
> On Tue, Nov 22, 2011 at 04:40, Benjamin Sanderse <B.Sanderse at cwi.nl>wrote:
>
>> Hello all,
>>
>> I am trying to output parallel data in binary format that can be read by
>> Tecplot. For this I use the TecIO library from Tecplot, which provide a set
>> of Fortran/C subroutines. With these subroutines it is easy to write binary
>> files that can be read by Tecplot, but, as far as I can see, they can not
>> be directly used with parallel Petsc vectors. On a single processor
>> everything works fine, but on more processors it fails.
>> I am thinking now of different workarounds:
>>
>> 1. Create a sequential vector from the parallel vector, and call the
>> TecIO subroutines with this sequential vector. For large problems this will
>> probably be too slow, and actually I don't know how to copy the content of
>> a parallel vector into a sequential one.
>> 2. Write a tecplot file from each processor, with the data from that
>> processor. The problem is that this requires combining the files
>> afterwards, and this is probably not easy (certainly not in binary format?).
>> 3. Change the tecplot subroutines or write own binary output with
>> VecView(). It might not be easy to get the output right so that Tecplot
>> understands it.
>>
>
> Are you using DMDA or do you have your own unstructured mesh? Supposedly
> Tecplot can read HDF5, so you might be able to use PETSc's parallel HDF5
> viewer and still read it with Tecplot.
>
> What other formats does Tecplot support and how do they recommend handling
> parallelism? The open source visualization packages have put a great deal
> of effort into supporting many different data formats (including Tecplot's
> native format). It would be rather unfair if Tecplot didn't support some of
> the open source formats.
>
>
>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111122/4295d547/attachment.htm>