Using the CLI¶

This page go over how to use the CLI interface to convert a GGD to VTK.

Convert GGD to VTK using the CLI¶

IMAS-ParaView supports converting the GGD of an IDS to VTK format from a command-line interface (CLI). This can be done by using the ggd2vtk tool.

Example usage:

ggd2vtk imas:hdf5?path=testdb#edge_profiles output_dir

This will create the following tree file structure:

output_dir/
├── edge_profiles_0/
│   ├── edge_profiles_0_0_0.vtu
│   ├── edge_profiles_0_1_0.vtu
│   ├── edge_profiles_0_2_0.vtu
│   …
└── edge_profiles_0.vtpc

Here, the 0 in edge_profiles_0 denotes that is has converted the first time step. The vtpc file contains a vtkPartitionedCollection, which can directly be loaded into Paraview for visualization. The vtu files contain a vtkUnstructuredGrid, and can also be loaded into Paraview directly.

Converting specific time steps¶

The CLI tools allows for conversion of only a single time step, a range of time steps or all timesteps. The tool allows for index and time-based time slicing.

No time slicing¶

If no time slicing option are provided, only the first time step will be converted. To convert all time steps instead, use the -a or --all-times flag.

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -a

Index-based slicing¶

To convert specific time step indices or a range of time step indices, the -i or --index flag can be used.

To convert index 5:

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -i 5

To convert indices 5, 8, and 9:

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -i 5,8,9

To convert a range of indices, such as 2 upto 6 (including 2 and 6):

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -i 2:6

Time-based slicing¶

To convert specific time step or a range of time steps, the -t or --time flag can be used. The time values will be interpreted in seconds.

To convert time step at 5.5s:

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -t 5.5

To convert time steps 5.5s, 8s, and 9.1s:

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -t 5.5,8,9.1

To convert all time steps that fall between 2.2s and 6.6s:

$ ggd2vtk imas:hdf5?path=testdb#edge_profiles test_dir -t 2.2:6.6

Convert VTK to GGD grids using the CLI¶

IMAS-ParaView supports converting VTK files to GGD grids in an IDS using the vtk2ggd command-line tool.

Usage¶

The vtk2ggd command requires two arguments: the path to VTK files and the output URI where the IDS will be stored.

Single file conversion:

vtk2ggd example.vtpc imas:hdf5?path=output_db --ids_name edge_profiles

This converts a single .vtpc file to an IDS, at the given URI.

File series conversion:

vtk2ggd output_dir/ imas:hdf5?path=output_db

This converts all .vtpc files in the specified directory to a single IDS with multiple time steps. The files should be named following the pattern {ids_name}_0.vtpc, {ids_name}_1.vtpc, etc. The IDS name will be automatically inferred from the file names.

VTK File Format Requirements¶

The vtk2ggd converter has specific requirements for the VTK input files it can process:

• The converter can convert the following VTK files in the XML format:

  • A single .vtu file containing a vtkUnstructuredGrid.

  • A single .vtpc file containing a vtkPartitionedDataSetCollection with a single time step

  • A directory containing a file series of .vtpc files (e.g., edge_profiles_0.vtpc, edge_profiles_1.vtpc, etc.), one for each time step.

• When providing .vtpc files, each vtkPartitionedDataSet should contain exactly one partition containing a vtkUnstructuredGrid, otherwise the partition is skipped. Each vtkUnstructuredGrid will be converted into a separate grid subset in the GGD.

Limitations of VTK grid conversion¶

The converter can only output IDSs with:

• a linear GGD grid.

• a single space of a GGD grid.

• standard space geometries, not Fourier spaces.

• X, Y, Z coordinates (coordinate_identifier.x/y/z), or R, Phi, Z coordinates (when the --cylindrical_coordinates flag is enabled).

• the GGD grid structure itself, not any physical quantities (temperature, density, etc.) defined on the grids in the ggd AoS.

• a homogeneous time mode.