# FindAllArrayNames

VTKExamples/Cxx/IO/FindAllArrayNames

### Description

This example shows how to find out the names of all of the data arrays stored in a vtkPolyData.

### Code

FindAllArrayNames.cxx

    #include <vtkSmartPointer.h>
    #include <vtkPolyData.h>
    #include <vtkPointData.h>
    #include <vtkCellData.h>
    #include <vtkXMLPolyDataReader.h>
    #include <vtkSphereSource.h>
    #include <vtkCubeSource.h>
    #include <vtkXMLPolyDataWriter.h>

    #include <vector>
    #include <string>

    void FindAllData(vtkPolyData* polydata);

    int main(int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> polydata =
        vtkSmartPointer<vtkPolyData>::New();

      if(argc < 2)
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->Update();
        vtkSmartPointer<vtkXMLPolyDataWriter> writer =
          vtkSmartPointer<vtkXMLPolyDataWriter>::New();
        writer->SetFileName("test.vtp");
        writer->SetInputConnection(sphereSource->GetOutputPort());
        writer->Write();

        polydata = sphereSource->GetOutput();
      }
      else
      {
        vtkSmartPointer<vtkXMLPolyDataReader> reader =
          vtkSmartPointer<vtkXMLPolyDataReader>::New();
        reader->SetFileName(argv[1]);
        reader->Update();
        polydata = reader->GetOutput();
      }

      FindAllData(polydata);

      return EXIT_SUCCESS;
    }

    void FindAllData(vtkPolyData* polydata)
    {
      std::cout << "Normals: " << polydata->GetPointData()->GetNormals() << std::endl;

      vtkIdType numberOfPointArrays = polydata->GetPointData()->GetNumberOfArrays();
      std::cout << "Number of PointData arrays: " << numberOfPointArrays << std::endl;

      vtkIdType numberOfCellArrays = polydata->GetCellData()->GetNumberOfArrays();
      std::cout << "Number of CellData arrays: " << numberOfCellArrays << std::endl;

      std::cout << "Type table/key: " << std::endl;;
      //more values can be found in <VTK_DIR>/Common/vtkSetGet.h
      std::cout << VTK_UNSIGNED_CHAR << " unsigned char" << std::endl;
      std::cout << VTK_UNSIGNED_INT << " unsigned int" << std::endl;
      std::cout << VTK_FLOAT << " float" << std::endl;
      std::cout << VTK_DOUBLE << " double" << std::endl;

      for(vtkIdType i = 0; i < numberOfPointArrays; i++)
      {
        // The following two lines are equivalent
        //arrayNames.push_back(polydata->GetPointData()->GetArray(i)->GetName());
        //arrayNames.push_back(polydata->GetPointData()->GetArrayName(i));
        int dataTypeID = polydata->GetPointData()->GetArray(i)->GetDataType();
        std::cout << "Array " << i << ": " << polydata->GetPointData()->GetArrayName(i)
                  << " (type: " << dataTypeID << ")" << std::endl;
      }

      for(vtkIdType i = 0; i < numberOfCellArrays; i++)
      {
        // The following two lines are equivalent
        //polydata->GetPointData()->GetArray(i)->GetName();
        //polydata->GetPointData()->GetArrayName(i);
        int dataTypeID = polydata->GetCellData()->GetArray(i)->GetDataType();
        std::cout << "Array " << i << ": " << polydata->GetCellData()->GetArrayName(i)
                  << " (type: " << dataTypeID << ")" << std::endl;
      }
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(FindAllArrayNames)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(FindAllArrayNames MACOSX_BUNDLE FindAllArrayNames.cxx )

    target_link_libraries(FindAllArrayNames ${VTK_LIBRARIES})

### Download and Build FindAllArrayNames

Click here to download FindAllArrayNames and its CMakeLists.txt file. Once the tarball FindAllArrayNames.tar has been downloaded and extracted,

    cd FindAllArrayNames/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./FindAllArrayNames

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.