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GaussianRandomNumber

vtk-examples/Cxx/SimpleOperations/GaussianRandomNumber

Description

This example generates 3 random numbers from a Gaussian distribution with mean 0.0 and standard deviation 2.0.

Other languages

See (CSharp)

Question

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

Code

GaussianRandomNumber.cxx

#include <vtkBoxMuellerRandomSequence.h>
#include <vtkNew.h>

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

  vtkNew<vtkBoxMuellerRandomSequence> randomSequence;

  // Generate numRand random numbers from a Gaussian distribution with mean 0.0
  // and standard deviation 2.0
  auto mean = 0.0;
  auto standardDeviation = 2.0;
  for (unsigned int i = 0; i < numRand; i++)
  {
    auto a = randomSequence->GetScaledValue(mean, standardDeviation);
    randomSequence->Next();
    std::cout << a << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(GaussianRandomNumber)

find_package(VTK COMPONENTS 
  vtkCommonCore
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping GaussianRandomNumber: ${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(GaussianRandomNumber MACOSX_BUNDLE GaussianRandomNumber.cxx )
  target_link_libraries(GaussianRandomNumber PRIVATE ${VTK_LIBRARIES})
else()
  # Prevent a "command line is too long" failure in Windows.
  set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
  add_executable(GaussianRandomNumber MACOSX_BUNDLE GaussianRandomNumber.cxx )
  target_link_libraries(GaussianRandomNumber PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS GaussianRandomNumber
    MODULES ${VTK_LIBRARIES}
    )
endif()

Download and Build GaussianRandomNumber

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

cd GaussianRandomNumber/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:

./GaussianRandomNumber

WINDOWS USERS

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