[vtkusers] Setting multiple scalars to a dataset

[Berk Geveci]

Read your data into 7 different arrays (assuming there are 7 scalar
values, if some are vectors, read them into separate 3 component
arrays). You can freely mark any of those as the active scalars, 
vectors (only 3 component arrays) etc. If you are using VTK 4.0 or
later that is. Check my few previous postings, the examples:
VTK/Examples/DataManipulation/Tcl/Arrays.tcl
VTK/Examples/DataManipulation/Tcl/FinancialField.tcl
and the latest User's Guide for more information.

-Berk


On Fri, 2002-05-31 at 08:12, Steve Boyd wrote:
> Hello,
> 
> I have made a reader class that reads my FE data results and generates a
> vtkUnstructuredGrid dataset, including associated scalars and vectors
> (from the FE output).  For example, I read stress scalar results into a
> vtkFloatArray (7 components), but I'm not sure how to set this data to
> the vtkUnstructuredGrid dataset.  In the tidbit of code, only the first
> component becomes 'active' (as expected after reading some e-mails in
> the archive).
> 
> My question:  What is the best way to set the scalar data?  Do I have to
> set a 1 component array in my reader source, or can I set all 7
> components and then 'activate' the component for filters further down
> the pipeline?  I don't want to have to re-read my entire input file
> every time I look at a different component...
> 
> Thanks for any suggestions.
> 
> Steve
> 	
>   vtkUnstructuredGrid   *output = this->GetOutput();
> 
>   ...
> 
>   vtkFloatArray *elementstresses = vtkFloatArray::New();
>     elementstresses->SetNumberOfComponents(7);
>     elementstresses->SetNumberOfTuples(nCells);  // then read in data
> 
>   ...
> 
>   if ( elementstresses != NULL )
>     {
>     output->GetCellData()->SetScalars(elementstresses);
>     }
> 
> 
> 
> 
> 
> -- 
> Steven Boyd, PhD
> 
> Institute for Biomedical Engineering
> ETH and University Zuerich
> Moussonstrasse 18
> 8044 Zuerich, Switzerland
> 
> tel. +41.1.632.4591  fax. +41.1.632.1214  boyd at biomed.ee.ethz.ch
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