[vtkusers] The best way to represent a multi-dimensional dataset?

[Maurice van de Rijzen]

Jesse Neri wrote:

>  
>
>>-----Original Message-----
>>From: vtkusers-admin at public.kitware.com
>>[mailto:vtkusers-admin at public.kitware.com]On Behalf Of Maurice van de
>>Rijzen
>>Sent: Wednesday, September 04, 2002 8:24 AM
>>To: vtkusers
>>Subject: [vtkusers] The best way to represent a multi-dimensional
>>dataset?
>>
>>
>>Dear all,
>>
>>I want to visualize a 5D-seismic dataset which is on a 
>>uniform sampled grid.
>>In order to do this I want  to create a 3D subset which I visualize 
>>using slices.
>>To import the dataset I want to use vtkImageReader2.
>>But vtkImageReader2 can hold 2D or 3D data.
>>Can someone tell me how I can import a 5D dataset.
>>Can someone also give me a hint on  how to use the 5D dataset 
>>to obtain 
>>a 3D subset( By taking for 2 dimensions a constan, user-given value).
>>
>>Thanks,
>>Maurice
>> 
>>    
>>
>This mya not be the best or only way, but here is how I do it:
>
>Read all the data into a vtkFieldArray.  The preferred method to do 
>this is is with a vtkProgrammableDataObjectSource.
>
>Then, construct the structured grid data (spatial coordinates only, 
>not data values!) using the vtkDataObjectToDataSetFilter.
>
>Then, I choose which data is mapped to the coordinates, using the
>vtkFieldDataToAttributeDataFilter. I use repeated calls to this
>to update the data values, and reuse the spatial cooridates.
>It cna be used for scalar and vecotr data.  
>
>A useful example of this process is the FinancialField.tcl
>example, in the DataManiuplation category.
>
>Jess
>
>--
>Jess Neri   neri at hobbes.nrl.navy.mil   (202) 404-4365 
>Pulsed Power Physics Branch, Plasma Physics Division  
>Naval Research Laboratory, Washington DC   20375      
>
> 
>  
>
This surely may be useful to me but its nit clear to me what all the 
different steps do.
Maybe I need to clarify my setup:
I'm using a 4D uniform grid which is not explicitly given in my dataset 
but it can be constructed from it.
The signal at each grid-point consists of a uniform sampled (time)-serie 
so this gives me a 5D scalar dataset.

    - I'm using a nigthly build version of august 19 and that doesn't 
include a vtkFieldArray so I assume that I need to use vtkDataArray?
    - As far as I understand, I need to put all  the time-series for 
each 4D-grid-point into  one long field. This can be done by using 
vtkProgrammableDataObjectSource.
    - The next step is to add the structured grid to the dataArray. But 
it isn't clear to me in which step I have to do this.
       You said I had to do this using vtkDataObjectToDataSetFilter but 
this can only create 3D structured grid data.
       So prior feeding the dataArray into vtkDataObjectToDataSetFilter 
I need to add the structured grid (adding for rows containg the 
'spatial' coordinates of the grid)?
       Can I do this also by using vtkProgrammableDataObjectSource?
    - What is exactly the role ofvtkFieldDataToAttributeDataFilter? 
(afaik it maps some parts of the selected fields into a dataset that is 
futher on used in the visualization.

Thanks in advance.

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