This is a quick run-through of how to use vtkxml-builder to create a set of VTU files from a set of Python lists.
So, say we have a set of particles that we want to visualize using ParaView or something similar to that. Each particle has a three-tuple coordinate, a radius and a temperature.
>>> x = [1.5, 1.0, 2.5]
>>> y = [0.5, 3.0, 2.0]
>>> z = [2.5, 1.5, 3.0]
>>> r = [1.0, 2.0, 1.5]
>>> t = [0.0, 0.5, 0.5]
So now we have three lists to represent the position. The particles are located at (1.5, 0.5, 2.5), (1.0, 3.0, 1.5), and (2.5, 2.0, 3.0). Their radii are 1.0, 2.0, and 1.5, and their temperatures are 0.0, 0.5, and 0.5.
Now we want to actually write some VTU files. We instantiate a VtuWriter, then call its write_vtu_file() method and pass in our data. We use the scalars parameter to pass in our scalar data series (radius and temperature) and the vectors parameter to pass in our vectors. We also specify a file name and, optionally, data types (if you don’t specify types they will be guessed). Also, note that we need to provide the name of the data series to be treated as positions. This is a special category in VTK, so it needs to be included. The default is “positions”, so if you use that name, you don’t have to specify it.
>>> writer = VtuWriter()
>>> scalars = {'radius': r, 'temp': t}
>>> vectors = {'position': [x, y, z]}
>>> writer.write_vtu_file('vtu0.vtu', scalars, vectors, pname='position')
This will write a VTU file called “vtu0.vtu” to the current directory. Successive calls to write_vtu_file() can then be used to create additional files.