# Unrecongnized keyword in vtk file
**URL:** https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776
**Category:** ParaView Support
**Created:** [January 13, 2022, 9:44pm UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776 "2022-01-13T21:44:57Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 13, 2022, 9:44pm UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/1 "2022-01-13T21:44:57Z")
Dear ParaView support,
I am trying to visualize a vtk file, but it gave me an ‘Unrecongnized keyword’ error. The full message is
ERROR: In /opt/glr/paraview/paraview-ci/build/superbuild/paraview/src/VTK/IO/Legacy/vtkUnstructuredGridReader.cxx, line 320
vtkUnstructuredGridReader (0x7fcdb1a1a570): Unrecognized keyword: �
Is it because the data is not written correctly in vtk file or something else. Any help would be appreciated. The attached is one example file.
[CPG\_Reservoir0001.vtk](https://discourse.paraview.org/uploads/short-url/jKDk4lrDGx8ShnZydwThkRk5lNg.vtk) (1.5 MB)
---
### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [January 14, 2022, 7:52am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/2 "2022-01-14T07:52:45Z")
You file is full of garbage characters. Did you look at the contents?
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 14, 2022, 8:08am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/3 "2022-01-14T08:08:27Z")
Thanks for your reply. Sorry I am very new to paraview and vtk. I am not sure how to open vtk files and check their contents. Do you have any suggestions.
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### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [January 14, 2022, 8:09am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/4 "2022-01-14T08:09:56Z")
It’s a text file.
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 14, 2022, 10:09am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/5 "2022-01-14T10:09:49Z")
Hi Todd, really appreciate your help. I looked into the vtk files. Is it true that the problem starts from POINTS data. Sorry for keeping asking stupid questions.
Below is the part of Matlab code used to save the data into vtk files. Do you notice any obvious mistake that could cause the problem.
```auto
function PlotReservoirSolution(obj, Reservoir, Grid)
%Write a VTK file for Reservoir
fileID = fopen(strcat(obj.FileName, '_Reservoir', num2str(obj.VTKindex,'%04d'),'.vtk'), 'w');
fprintf(fileID, '# vtk DataFile Version 2.0\n');
fprintf(fileID, 'DARSim 2 Reservoir Simulator\n');
if obj.isBinary
fprintf(fileID, 'BINARY\n');
else
fprintf(fileID, 'ASCII\n');
end
fprintf(fileID, '\n');
%
fprintf(fileID, 'DATASET UNSTRUCTURED_GRID\n');
VTK_Nodes = Grid.CornerPointGridData.Nodes;
if Grid.CornerPointGridData.N_TotalCells ~= Grid.CornerPointGridData.N_ActiveCells
obj.ReferenceDepth = max(VTK_Nodes(:,3));
% If the domain is a Cartesian box, there is no need to invert the Z coordinates.
% But if the domain is not a Cartesian boxTherefore, the Z coordinates are inverted only for the sake of the visualization.
VTK_Nodes(:,3) = obj.ReferenceDepth - VTK_Nodes(:,3);
end
fprintf(fileID, ['POINTS ' num2str(Grid.CornerPointGridData.N_Nodes) ' double\n']);
if obj.isBinary
fwrite(fileID, VTK_Nodes','float', 'b');
else
fprintf(fileID, '%f %f %f\n',VTK_Nodes');
end
fprintf(fileID, '\n');
%
fprintf(fileID, ['CELLS ' num2str(Grid.N) ' ' num2str(Grid.N*(1+8)) '\n']);
indMatrix = horzcat(8*ones(Grid.N,1) , Grid.CornerPointGridData.Cells.Vertices-1 );
if obj.isBinary
fwrite(fileID, indMatrix','float', 'b');
else
fprintf(fileID, '%d %d %d %d %d %d %d %d %d\n', indMatrix');
end
fprintf(fileID, '\n');
%
fprintf(fileID, ['CELL_TYPES ' num2str(Grid.N) '\n']);
if obj.isBinary
fwrite(fileID, 11*ones(1,Grid.N),'float', 'b');
else
fprintf(fileID, '%d ', 11*ones(1,Grid.N));
end
fprintf(fileID, '\n\n');
% Print all existing variables
fprintf(fileID, 'CELL_DATA %d\n', Grid.N);
N_var = double(Reservoir.State.Properties.Count);
Names = Reservoir.State.Properties.keys;
for i=1:N_var
if strcmp(Reservoir.State.Properties(Names{i}).Type, 'scalar')
obj.PrintScalar2VTK(fileID, Reservoir.State.Properties(Names{i}).Value, [' ',Names{i}]);
else
obj.PrintVector2VTK(fileID, Reservoir.State.Properties(Names{i}).Value, [' ',Names{i}]);
end
fprintf(fileID, '\n');
end
% Add the "isFractured" flag for reservoir grid cells that are overlapped by a fracture (if any)
if ~isempty(Grid.ListOfFracturedReservoirCells)
isFractured = zeros(Grid.N,1);
isFractured(Grid.ListOfFracturedReservoirCells) = 1;
obj.PrintScalar2VTK(fileID, isFractured, ' isFractured');
fprintf(fileID, '\n');
end
% Add the "isPerforated" flag for reservoir grid cells that are overlapped by a fracture (if any)
if ~isempty(Grid.ListOfPerforatedCells)
isPerforated = zeros(Grid.N,1);
isPerforated(Grid.ListOfPerforatedCells) = 1;
obj.PrintScalar2VTK(fileID, isPerforated, ' isPerforated');
fprintf(fileID, '\n');
end
% Add the cell indices
obj.PrintScalar2VTK(fileID, [1:Grid.N]', ' Index');
fprintf(fileID, '\n');
% Add the cell volumes
obj.PrintScalar2VTK(fileID, Grid.Volume, ' Volume');
fprintf(fileID, '\n');
% Add ADM ACTIVETime
obj.PrintScalar2VTK(fileID, Grid.ActiveTime, ' ACTIVETime');
fprintf(fileID, '\n');
% Add ADM ACTIVEFine (coarse grids)
obj.PrintScalar2VTK(fileID, Grid.Active, ' ACTIVEFine');
fprintf(fileID, '\n');
fclose(fileID);
if obj.PlotInterfaces
obj.PlotInternalFaces(Reservoir, Grid);
end
end
```
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### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [January 14, 2022, 10:27am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/6 "2022-01-14T10:27:59Z")
The data output is binary so it’s impossible to analyse. I suggest you generate the equivalent ASCII file and see if that can be read first.
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 14, 2022, 10:29am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/7 "2022-01-14T10:29:19Z")
Thanks for the tips. I will try it now.
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### Author:  [@Kenichiro-Yoshimi](https://discourse.paraview.org/u/Kenichiro-Yoshimi)
#### Post date: [January 14, 2022, 11:37am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/8 "2022-01-14T11:37:21Z")
In the VTK file, the precision of POINTS is set to **double**.
> POINTS 10302 double
On the other hand, the matlab source code specifies a precision of **float**.
```matlab
fwrite(fileID, VTK_Nodes','float', 'b');
```
This may be causing inconsistencies.
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 17, 2022, 10:10am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/9 "2022-01-17T10:10:44Z")
Hi Todd and Kyoshimi,
Thanks for your help. Firstly, I tried to follow Todd’s suggestion, generating the equivalent ASCII file. Everything works in that way. Paraview can read the file with no problem. The attached is an example ASCII file.
So I would say the problem is rooted from those fwrite commands used to save the data to binary files, like you suggested. I also noticed that inconsistency and tried to change the fwrite command to
```auto
fwrite(fileID, VTK_Nodes','double', 'b');
```
but the paraview would crash when I tried to visualize it. Below is a picture of the crash message. Do you guys know what may causes this problem.
[CPG\_Reservoir0000.vtk](https://discourse.paraview.org/uploads/short-url/2uNxSpc00x1HnYCSpAillxx1W79.vtk) (2.3 MB)
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### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [January 17, 2022, 10:23am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/10 "2022-01-17T10:23:39Z")
Did you check **PrintScalar2VTK()** as well?
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 17, 2022, 10:27am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/11 "2022-01-17T10:27:09Z")
Hi Todd, yes, it is written in this way. I did not notice an obvious mistake.
```auto
function PrintScalar2VTK(obj, fileID, scalar, name)
%Print a scalar in VTK format
fprintf(fileID, '\n');
fprintf(fileID, strcat('SCALARS ', name,' double 1\n'));
fprintf(fileID, 'LOOKUP_TABLE default\n');
if obj.isBinary
fwrite(fileID, scalar', 'double', 'b');
else
fprintf(fileID,'%1.5e ', scalar);
end
end
```
---
### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [January 17, 2022, 10:52am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/12 "2022-01-17T10:52:39Z")
I think you need to start with a file containing just a couple of points, cells and scalars to see what is causing the crash by a process of elimination. Gradually adding more data as the read succeeds.
---
### Author:  [@Kenichiro-Yoshimi](https://discourse.paraview.org/u/Kenichiro-Yoshimi)
#### Post date: [January 17, 2022, 11:40am UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/13 "2022-01-17T11:40:35Z")
At least, since **CELLS** and **CELL\_TYPES** are integer arrays, you should specify ‘int’ as the **precision** of fwrite to output them.
---
### Author:  [@Ziliang](https://discourse.paraview.org/u/Ziliang)
#### Post date: [January 17, 2022, 2:14pm UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/14 "2022-01-17T14:14:59Z")
Hi Kyoshimi and Todd,
Thanks for your reply again. You are right! I changed the fwrite commands to
```auto
fwrite(fileID, VTK_Nodes','double', 'b');
fwrite(fileID, indMatrix','int', 'b');
fwrite(fileID, 11*ones(1,Grid.N),'int', 'b');
```
for **POINTS** , **CELLS** and **CELL\_TYPES** respectively. It works this time. Paraview read the binary file with no problem. The attached is a newly generated BINARY file example.
[CPG\_Reservoir0000.vtk](https://discourse.paraview.org/uploads/short-url/fqd4ShqAAAjqyiGVHSe8S1RZO2s.vtk) (1.6 MB)
It seems like indeed the problem is caused by the inconsistencies when specifying the precision. Thank you both for the helpful discussion. Really appreciate that.
All the best,
Ziliang
---
### Author:  [@Jann5s](https://discourse.paraview.org/u/Jann5s)
#### Post date: [May 15, 2023, 1:52pm UTC](https://discourse.paraview.org/t/unrecongnized-keyword-in-vtk-file/8776/15 "2023-05-15T13:52:20Z")
@Ziliang,
I seem to have the same issue, but I have troubles reconstructing the correct version from your initial code and the corrections in your last post. Would you mind sharing the final code?