Data array multi-component labelling

ParaView Support
1

My problem is in the Paraview GUI:

Any vector components can be colored by Magnitude, or by components X, Y, Z. However, Is there a way to enforce this labelling to Ux, Uy, Uz (for example), instead of the spatial-centric notation X, Y,Z? (Similary with tensor components: Magnitude,XX, YY, ZZ, etc…)

Thanks in advance,

Jack

2

This can be done by setting the component name on the vtk data itself.
You could create a simple programmable filter that would rename the component.

3

Do you mean that the component names of vectors/tensors can be set in a VTK file directly? Any pointers to the format specification in that case?

4

No I mean programmatically, although that is doable on the file format itself:

https://kitware.github.io/vtk-examples/site/VTKFileFormats/

5

Thanks for the link, although I didn’t find anything about label names there. To clarify what I want: I want to put the label names (Ux, Uy, Uz) in the VTK file itself, is that possible?

6

I’m afraid this is not supported by .vtk files.

7

I see, thanks. Slightly tangential is there any interest in annotating 2nd order non-symmetric tensors with XX, YY, …, just like symmetric tensors? I could not find any discussion about this.

8

no idea what you mean, sounds unrelated to the discussion at hand. please open your own topic if needed.

9

To precise my thinking, this is not supported by .vtk file but very well supported by many other formats, like .vtu/vtp files.

10

I see. I was using VTK file as a collective term – I am mostly interested in .vtu, so maybe that could work then?

11

Actually supported by both .vtk and .vtu/vtp:
cname.vtu (2.4 KB)
cname.vtk (528 Bytes)
cname.vtp (3.4 KB)

vtk:

[glow@arch ~/tmp]$ cat cname.vtk 
# vtk DataFile Version 5.1
vtk output
ASCII
DATASET POLYDATA
POINTS 1 float
0 0 0 
METADATA
INFORMATION 2
NAME L2_NORM_RANGE LOCATION vtkDataArray
DATA 2 0 0 
NAME L2_NORM_FINITE_RANGE LOCATION vtkDataArray
DATA 2 0 0 

VERTICES 2 1
OFFSETS vtktypeint64
0 1 
CONNECTIVITY vtktypeint64
0 
POINT_DATA 1
FIELD FieldData 1
Vals 3 1 double
17 13 7 
METADATA
COMPONENT_NAMES

name

INFORMATION 2
NAME L2_NORM_RANGE LOCATION vtkDataArray
DATA 2 22.5167 22.5167 
NAME L2_NORM_FINITE_RANGE LOCATION vtkDataArray
DATA 2 22.5167 22.5167

vtp/vtu:

[glow@arch ~/tmp]$ cat cname.vtu 
<VTKFile type="UnstructuredGrid" version="1.0" byte_order="LittleEndian" header_type="UInt64">
  <UnstructuredGrid>
    <Piece NumberOfPoints="1"                    NumberOfCells="1"                   >
      <PointData>
        <DataArray type="Float64" Name="Vals" NumberOfComponents="3" ComponentName1="name" format="appended" RangeMin="22.516660498"         RangeMax="22.516660498"         offset="0"                   >
          <InformationKey name="L2_NORM_RANGE" location="vtkDataArray" length="2">
            <Value index="0">
1 Like
12

Perfect, just what I was looking for.