Question

我想使用Python VTK模块从.vtu文件中提取数据数组。该文件如下所示（文件末尾的原始数据被省略）：

<?xml version="1.0"?>
<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">
  <UnstructuredGrid>
    <Piece NumberOfPoints="10471" NumberOfCells="64892">
      <PointData>
        <DataArray type="Float64" Name="potential" NumberOfComponents="1" format="appended" offset="0"/>
        <DataArray type="Float64" Name="electric field" NumberOfComponents="3" format="appended" offset="83772"/>
      </PointData>
      <CellData>
        <DataArray type="Int32" Name="GeometryIds" format="appended" offset="335080"/>
      </CellData>
      <Points>
        <DataArray type="Float64" NumberOfComponents="3" format="appended" offset="594652"/>
      </Points>
      <Cells>
        <DataArray type="Int32" Name="connectivity" format="appended" offset="845960"/>
        <DataArray type="Int32" Name="offsets" format="appended" offset="1865068"/>
        <DataArray type="Int32" Name="types" format="appended" offset="2124640"/>
      </Cells>
    </Piece>
  </UnstructuredGrid>
<AppendedData encoding="raw">

我尝试使用以下python代码提取数据：

import numpy
from vtk import vtkUnstructuredGridReader
from vtk.util import numpy_support as VN

reader = vtkUnstructuredGridReader()
reader.SetFileName("charged_wire.vtu")
reader.ReadAllVectorsOn()
reader.ReadAllScalarsOn()
reader.Update()

data = reader.GetOutput()
potential = data.GetPointData().GetScalars("potential")

print(type(potential))

不幸的是，该程序将NoneType打印为输出，并且我不确定是否需要更改以提取potential数组中的数据存储区吗？

Answer 1

更轻巧的解决方案是使用meshio（我编写）。除numpy外，它没有必需的依赖项。使用

安装

pip install meshio

并使用

读取文件

import meshio

mesh = meshio.read("foo.vtu")
# mesh.points, mesh.cells, mesh.point_data, ...

Answer 2

您使用的阅读器不正确，这是一个.vtu文件，您必须使用vtkXMLUnstructuredGridReader。

import vtk.vtk

# The source file
file_name = "path/to/your/file.vtu"

# Read the source file.
reader = vtk.vtkXMLUnstructuredGridReader()
reader.SetFileName(file_name)
reader.Update()  # Needed because of GetScalarRange
output = reader.GetOutput()
potential = output.GetPointData().GetArray("potential")

从原始VTK（.vtu）文件读取数据

2 个答案: