# Legacy VTK: associating multiple unknowns with each point

**URL:** https://discourse.vtk.org/t/legacy-vtk-associating-multiple-unknowns-with-each-point/5599
**Category:** Support
**Tags:** file-formats
**Created:** [April 21, 2021, 10:25am UTC](https://discourse.vtk.org/t/legacy-vtk-associating-multiple-unknowns-with-each-point/5599 "2021-04-21T10:25:14Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![mturner](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/m/f4b2a3/32.png) [@mturner](https://discourse.vtk.org/u/mturner)
#### Post date: [April 21, 2021, 10:25am UTC](https://discourse.vtk.org/t/legacy-vtk-associating-multiple-unknowns-with-each-point/5599/1 "2021-04-21T10:25:14Z")

</div>

Hi, I might have missed something obvious in the documentation, but it is not clear to me how I can associate multiple (say, up to 20) scalars with each point in a legacy VTK STRUCTURED\_POINTS representation.

Currently I would write the heading of a 2D leg.VTK file as follows

```
# vtk DataFile Version 3.0
insert some description of the data here
ASCII
DATASET STRUCTURED_POINTS
DIMENSIONS 297 297 1                                                        
ORIGIN 0.000925926 0.000925926 0.000925926
SPACING 0.0033607685993265997 0.0033607685993265997 0.0033607685993265997

```

And then have 4 POINT\_DATA fields each defining a single variable for each point in the above defined topology:

```
POINT_DATA 88209
SCALARS unknown_<var num.> float 1
LOOKUP_TABLE unknown_<var num.>_table
<88209 floats now follow>

```

I guess this is probably the wrong way to associate multiple variables with individual points in legacy VTK as I can only view the first POINT\_DATA field - i.e. unknnown\_1 - in paraview. It returns the following error when loaded into paraview:

> ERROR: In /opt/glr/paraview/paraview-ci/build/superbuild/paraview/src/VTK/IO/Legacy/vtkDataReader.cxx, line 1007  
> vtkStructuredPointsReader (0x7fbc4d6f8810): Unsupported point attribute type: point\_data for file: vtk\_file.vtk

What is the correct way?

Thank you for any guidance.