# EdgeWeights

VTKExamples/Cxx/Graphs/EdgeWeights

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### Code¶

EdgeWeights.cxx

#include <vtkSmartPointer.h>
#include <vtkDataSetAttributes.h>
#include <vtkDoubleArray.h>
#include <vtkMutableUndirectedGraph.h>
#include <vtkCircularLayoutStrategy.h>
#include <vtkDoubleArray.h>
#include <vtkGraphLayoutView.h>
#include <vtkIntArray.h>
#include <vtkMutableUndirectedGraph.h>
#include <vtkRenderWindowInteractor.h>

int main(int, char *[])
{
vtkSmartPointer<vtkMutableUndirectedGraph> g =
vtkSmartPointer<vtkMutableUndirectedGraph>::New();

// Create 3 vertices

// Create a fully connected graph

// Create the edge weight array
vtkSmartPointer<vtkDoubleArray> weights =
vtkSmartPointer<vtkDoubleArray>::New();
weights->SetNumberOfComponents(1);
weights->SetName("Weights");

// Set the edge weights
weights->InsertNextValue(1.0);
weights->InsertNextValue(1.0);
weights->InsertNextValue(2.0);

// Add the edge weight array to the graph

std::cout << "Number of Weights: "
<< dynamic_cast<vtkDoubleArray*>(
g->GetEdgeData()->GetArray("Weights"))->GetNumberOfTuples()
<< std::endl;

for(vtkIdType i = 0; i < weights->GetNumberOfTuples(); i++)
{
double w = weights->GetValue(i);
std::cout << "Weight " << i << " : " << w << std::endl;
}

vtkSmartPointer<vtkGraphLayoutView> graphLayoutView =
vtkSmartPointer<vtkGraphLayoutView>::New();
graphLayoutView->SetEdgeLabelVisibility(true);
graphLayoutView->SetEdgeLabelArrayName("Weights");
graphLayoutView->ResetCamera();
graphLayoutView->Render();
graphLayoutView->GetInteractor()->Start();

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(EdgeWeights)

find_package(VTK COMPONENTS
vtkCommonCore
vtkCommonDataModel
vtkInfovisLayout
vtkInteractionStyle
vtkRenderingContextOpenGL2
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingGL2PSOpenGL2
vtkRenderingOpenGL2
vtkViewsInfovis QUIET)
if (NOT VTK_FOUND)
message("Skipping EdgeWeights: ${VTK_NOT_FOUND_MESSAGE}") return () endif() message (STATUS "VTK_VERSION:${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
# old system
include(${VTK_USE_FILE}) add_executable(EdgeWeights MACOSX_BUNDLE EdgeWeights.cxx ) target_link_libraries(EdgeWeights PRIVATE${VTK_LIBRARIES})
else ()
# include all components
target_link_libraries(EdgeWeights PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS EdgeWeights MODULES${VTK_LIBRARIES}
)
endif ()


cd EdgeWeights/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:

./EdgeWeights


WINDOWS USERS

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