Read/write plt files in parallel and mesh sharing feature

Creating Tecplot binary data files

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zonexo
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Read/write plt files in parallel and mesh sharing feature

Postby zonexo » Sat May 31, 2008 8:18 pm

Hi,

I'm trying to read/write plt file in parallel using MPI. I wonder if it is possible. My data are separated into each region belonging to each processor.

How should I call TecIni110,TecZne110? Should they be called by 1 processor or all processors? I believe for tecdat110, I just need to read/write each processor in order starting from the 1st processor. Is that correct?

Another thing is the new sharing of mesh for transient data. I tried to look inside the dataformat.pdf but I can't seem to find the relevant info regarding this new feature. Is it in the pdf? Also I can't seem to download the windows xp 32bit tecio library.

Thank you very much.

Regards

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Re: Read/write plt files in parallel and mesh sharing featur

Postby bsanderse » Thu Nov 24, 2011 12:22 am

I have the same question regarding writing binary .plt files in parallel. Does anybody know a solution for this?

mkwakkel
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Re: Read/write plt files in parallel and mesh sharing featur

Postby mkwakkel » Sun Nov 27, 2011 11:21 pm

Recently I have managed to write binary plt files in parallel with MPI-IO from Fortran. I just write the entire plt file by by own written subroutines, so I don't use TecIni110, TecZne110, etc. You can find the binary data structure at the end of the following Data Format Guide: download.tecplot.com/tecio/2009/dataformat.pdf (see Appendix A).

My advice: start with an easy binary plt, then modify it to be able to write it in parallel. The first part of the file (header) will not change when you move to MPI-IO, only the data part will.

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Re: Read/write plt files in parallel and mesh sharing featur

Postby jfinn » Wed Sep 19, 2012 8:18 am

Sorry to beat a dead horse here, but does anyone have a solution for this?

I believe my question is very similar to the original post. I can currently write ASCII files in Tecplot format from our parallel (MPI) flow solver. First, the the zone header is written with 1 processor. Then every processor writes its own data and connectivity in parallel. Is it possible to follow a similar procedure with the tecio library functions?

Thanks in advance,

Justin


zonexo wrote:Hi,

I'm trying to read/write plt file in parallel using MPI. I wonder if it is possible. My data are separated into each region belonging to each processor.

How should I call TecIni110,TecZne110? Should they be called by 1 processor or all processors? I believe for tecdat110, I just need to read/write each processor in order starting from the 1st processor. Is that correct?

Another thing is the new sharing of mesh for transient data. I tried to look inside the dataformat.pdf but I can't seem to find the relevant info regarding this new feature. Is it in the pdf? Also I can't seem to download the windows xp 32bit tecio library.

Thank you very much.

Regards

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Scott Rumage
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Re: Read/write plt files in parallel and mesh sharing featur

Postby Scott Rumage » Thu Sep 20, 2012 7:06 am

A new function in the TecIO utility may be of help in what you are trying to accomplish. Here is the description:

TECNODE112

Writes a chunk of node data to the binary data file. This is the connectivity list for cell-based finite element zones (line segment, triangle, quadrilateral, brick, and tetrahedral zones). The connectivity list for face-based finite element zones (polygonal and polyhedral) is specified via TECPOLY112.

This function is similar to TECNOD112 but does not require that the entire connectivity list be provided at once. Rather, you may call TECNODE112 as many times as you like, providing connectivity information for as many elements as you like each time, so long as you eventually provide connectivity information for all elements in the zone.

This new TecIO library is located here: ftp://ftp.tecplot.com/misc/ and the file name is tecio_2012.tar.gz

jfinn
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Re: Read/write plt files in parallel and mesh sharing featur

Postby jfinn » Thu Sep 20, 2012 11:28 am

Thanks Scott.

I think this function could help.

Unfortunately, after digging a little deeper, it seems like I will have to do some other modifications to the TecIO source in order to use it with our code. The main problem (as far as I can see) is that writing data/connectivity to a single zone using multiple processors does not seem possible.

Justin

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Re: Read/write plt files in parallel and mesh sharing featur

Postby Jay » Tue Sep 25, 2012 8:23 am

Using TECNODE112 will allow you to write your connectivity for a zone in chunks, as mentioned.
TecIO does not currently support parallel access to the same file. A way to handle data from multiple processors is to generate the data with the different processors and then funnel it through a single processor at the end that makes all of the TecIO calls. For example, each processor could write out its data to temporary files. Then after the join, a single processor could make the TecIO calls using the data from the temp files in synchronized order.

Data can be shared between zones as specified in TECZNE112 or by using a grid file for static/shared data and solution files for the dynamic data.
Jay Noble
Tecplot Development

Tecplot, Inc.
Enjoy the View!
www.tecplot.com


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