[Paraview] paraview making up numbers

[John Doe]

Hello,

Thanks for answering my question.  I tried implementing a multi-group
file setup with the vtu files in the same directory as the vtm file.
Here is my vtm file:
<?xml version="1.0"?>
<VTKFile type="vtkMultiGroupDataSet" version="0.1" byte_order="LittleEndian" com
pressor="vtkZLibDataCompressor">
  <vtkMultiGroupDataSet>
    <DataSet group="0" dataset="0" file="mos_2d_0.vtu"/>
    <DataSet group="1" dataset="0" file="mos_2d_1.vtu"/>
    <DataSet group="2" dataset="0" file="mos_2d_2.vtu"/>
    <DataSet group="3" dataset="0" file="mos_2d_3.vtu"/>
  </vtkMultiGroupDataSet>
</VTKFile>

Where I assume that incrementing the group number is more important
than incrementing the dataset number.

However mos_2d_1.vtu and mos_2d_2.vtu have fields which I can not
access (do not appear) in paraview when I load the vtm file.  If I
load the files individually, I can see the fields I need just fine.  I
know the files are being loaded properly since the grid is complete.

How can I assure that all the fields for all the groups are accessible?

Regards,

Juan




On Tue, Jul 8, 2008 at 9:51 AM, Berk Geveci <berk.geveci at kitware.com> wrote:
> ---------- Forwarded message ----------
> From: Berk Geveci <berk.geveci at kitware.com>
> Date: Tue, Jul 8, 2008 at 10:51 AM
> Subject: Re: [Paraview] paraview making up numbers
> To: John Doe <ufnoise at gmail.com>
>
>
> Let me try to answer your questions.
>
>> 3. Different elements in the same region (lines, triangles), and
>> having completely different data arrays per element type.
>
> There is no file format that supports this because VTK/ParaView does
> not support it. The best way of achieving it is to write a different
> block per cell type that has different arrays.
>
>> I tried this and it created a vtm file, a directory, and a file in the
>> directory.  I could see places where there are a log of "nans" and
>> 1e307's.  Can paraview read nan's and what does it do with them.
>
> No. ParaView cannot read or handle nans. Nor does it support a concept
> of invalid value. All values of an arrays have to be defined. The only
> exception to this is the concept of "blanking" for structured grids
> (which blanks a whole point/cell not mark a value invalid).
>
>>  Is there anyway to create a flat file format for a vtm file?
>
> No.
>
>> Is the ensight format any easier, or just superior?  Any
>> recommendations for a format appreciated.
>
> Writing Ensight is definitely easier. Whether it is superior or not
> depends on your use case.
>
>> Requirements:
>> 1. Different regions (or pieces) have different data arrays with
>> completely unrelated names.
>>
>> Optional (But would be really, really nice):
>> 1. Documented
>> 2. Single file format
>
> You should look into the following formats:
>
> Ensight. See http://www.ensight.com/downloads/cat_view-82.html for
> documentation.
> * It is well documented
> * Supports multiple blocks/parts
> * Easy to read/write
> * It is not a single file format
>
> Exodus. See http://endo.sandia.gov/SEACAS/Documentation/exodusII.pdf
> * It is well documented
> * Supports multiple blocks/parts
> * Requires a library to read/write
> (http://sourceforge.net/projects/exodusii). It uses netcdf under the
> covers so you can directly the netcdf library too
> * It is a single file format
>
> Xdmf: See xdmf.org
> * It is somewhat well documented
> * Supports multiple blocks/parts
> * Requiers library (HDF5) to read/write
> * Each dataset is usually 2 files (one xml, one hdf5)
>
> -berk
>
>> On Thu, Jul 3, 2008 at 1:38 PM, John Doe <ufnoise at gmail.com> wrote:
>>> While I am learning about this new format.  Would it be reasonable for
>>> me to file a request that data arrays be initialized to zero in
>>> regions they are not specified?  If not possible, would it be more
>>> reasonable to file a request that the software warns people that
>>> paraview will not initialize data arrays?
>>>
>>> Thanks,
>>>
>>> Juan
>>>
>>> On Thu, Jul 3, 2008 at 1:23 PM, Berk Geveci <berk.geveci at kitware.com> wrote:
>>>> No, I am afraid it did not make into the documentation yet. It is easy
>>>> to create an example using ParaView. Load 2 unstructured grids, group
>>>> them together using the Group filter and then write the output as a
>>>> vtm file.
>>>>
>>>> -berk
>>>>
>>>> On Thu, Jul 3, 2008 at 12:35 PM, John Doe <ufnoise at gmail.com> wrote:
>>>>> Is there any documentation for the multi-block format?  It is not part
>>>>> of the file formats document I found online.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Juan
>>>>>
>>>>> On Wed, Jul 2, 2008 at 2:43 PM, Berk Geveci <berk.geveci at kitware.com> wrote:
>>>>>> It is required that all pieces in an XML unstructured file have the
>>>>>> exact same set of arrays. It is by coincidence that you are
>>>>>> experiencing crashes. You need to use multi-block dataset to group
>>>>>> together pieces with different fields. You may want to look at using
>>>>>> the XML-based multi-block file format (vtm extension) or EnSight
>>>>>> format for this. The former is not well documented yet, I am afraid.
>>>>>>
>>>>>> -berk
>>>>>>
>>>>>> On Tue, Jul 1, 2008 at 4:46 PM, John Doe <ufnoise at gmail.com> wrote:
>>>>>>> I have devices composed of pieces using an unstructured mesh in the
>>>>>>> xml file format.  Some of the pieces don't have data in them.  It
>>>>>>> appears that paraview makes up numbers for these regions.  Sometimes
>>>>>>> the numbers are unphysical, e.g. 1e+307.  Sometimes the numbers seem
>>>>>>> to be based on data from adjacent pieces.  Is there any way to tell
>>>>>>> paraview to use a reasonable values in regions for which data is not
>>>>>>> presented.
>>>>>>>
>>>>>>> This becomes important as each region (piece) of my device can have
>>>>>>> completely different physics.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Juan
>>>>>>> _______________________________________________
>>>>>>> ParaView mailing list
>>>>>>> ParaView at paraview.org
>>>>>>> http://www.paraview.org/mailman/listinfo/paraview
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>