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UniformRandomNumber

vtk-examples/Cxx/SimpleOperations/UniformRandomNumber

Description

This example generates 3 random numbers between 0 and 2 from a uniform distribution.

Other languages

See (CSharp)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

UniformRandomNumber.cxx

#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNew.h>

#include <time.h>

int main(int, char*[])
{
  // Set the number of random numbers we wish to produce to 3.
  unsigned int numRand = 3;

  vtkNew<vtkMinimalStandardRandomSequence> randomSequence;
  randomSequence->SetSeed(8775070);
  // Without this line, the random numbers will be the same every iteration.
  // randomSequence->SetSeed(time(NULL));

  // Generate numRand random numbers from a uniform distribution between 0.0
  // and 2.0
  for (unsigned int i = 0; i < numRand; i++)
  {
    auto a = randomSequence->GetRangeValue(0.0, 2.0);
    randomSequence->Next();

    std::cout << a << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(UniformRandomNumber)

find_package(VTK COMPONENTS 
  vtkCommonCore
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping UniformRandomNumber: ${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(UniformRandomNumber MACOSX_BUNDLE UniformRandomNumber.cxx )
  target_link_libraries(UniformRandomNumber PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(UniformRandomNumber MACOSX_BUNDLE UniformRandomNumber.cxx )
  target_link_libraries(UniformRandomNumber PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS UniformRandomNumber
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build UniformRandomNumber

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

cd UniformRandomNumber/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:

./UniformRandomNumber

WINDOWS USERS

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