ExtractArrayComponent
VTKExamples/Cxx/Utilities/ExtractArrayComponent
Code¶
ExtractArrayComponent.cxx
#include <vtkVersion.h> #include <vtkArrayCalculator.h> #include <vtkDoubleArray.h> #include <vtkPointData.h> #include <vtkPolyData.h> #include <vtkSmartPointer.h> int main(int, char *[]) { vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); points->InsertNextPoint(1.0, 0.0, 0.0); points->InsertNextPoint(2.0, 0.0, 0.0); points->InsertNextPoint(3.0, 0.0, 0.0); vtkSmartPointer<vtkDoubleArray> array = vtkSmartPointer<vtkDoubleArray>::New(); array->SetName("InputArray"); array->SetNumberOfComponents(3); array->InsertNextTuple3(1, 10, 100); array->InsertNextTuple3(2, 20, 200); array->InsertNextTuple3(3, 30, 300); vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New(); polydata->SetPoints(points); polydata->GetPointData()->AddArray(array); vtkSmartPointer<vtkArrayCalculator> arrayCalculator = vtkSmartPointer<vtkArrayCalculator>::New(); #if VTK_MAJOR_VERSION <= 5 arrayCalculator->SetInput(polydata); #else arrayCalculator->SetInputData(polydata); #endif arrayCalculator->AddVectorArrayName("InputArray"); arrayCalculator->SetFunction("InputArray . jHat"); // Extract component '1' from the InputArray by taking the dot product of each tuple with the vector (0,1,0) arrayCalculator->SetResultArrayName("OutputArray"); arrayCalculator->Update(); vtkSmartPointer<vtkDoubleArray> outputArray = vtkDoubleArray::SafeDownCast( arrayCalculator->GetPolyDataOutput()->GetPointData()->GetArray("OutputArray")); for(vtkIdType i = 0; i < outputArray->GetNumberOfTuples(); i++) { double val = outputArray->GetValue(i); std::cout << "output value " << i << ": " << val << std::endl; } return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ExtractArrayComponent) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ExtractArrayComponent MACOSX_BUNDLE ExtractArrayComponent.cxx) target_link_libraries(ExtractArrayComponent ${VTK_LIBRARIES})
Download and Build ExtractArrayComponent¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download ExtractArrayComponent and its CMakeLists.txt file. Once the tarball ExtractArrayComponent.tar has been downloaded and extracted,
cd ExtractArrayComponent/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:
./ExtractArrayComponent
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.