# GaussianRandomNumber

VTKExamples/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)

### Code

GaussianRandomNumber.cxx

    #include <vtkMath.h>
    #include <time.h>

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

      //without this line, the random numbers will be the same every iteration
      vtkMath::RandomSeed(time(NULL));

      //Generate numRand random numbers from a Gaussian distribution with mean 0.0 and standard deviation 2.0
      for(unsigned int i = 0; i < numRand; i++)
      {
        double a = vtkMath::Gaussian(0.0,2.0);
        std::cout << a << std::endl;
      }

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 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 ()
      # include all components
      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.