Method InitRandom

Src/Particle/AMReX_ParticleInit.H:972–1362

template <typename ParticleType, int NArrayReal, int NArrayInt,
          template<class> class Allocator, class CellAssignor>
void
ParticleContainer_impl<ParticleType, NArrayReal, NArrayInt, Allocator, CellAssignor>::
InitRandom (Long                    icount,
            ULong                   iseed,
            const ParticleInitData& pdata,
            bool                    serialize,
            RealBox                 containing_bx)
{
    BL_PROFILE("ParticleContainer<NSR, NSI, NAR, NAI>::InitRandom()");
    AMREX_ASSERT(iseed  > 0);
    AMREX_ASSERT(icount > 0);

    AMREX_ASSERT(m_gdb != nullptr);

    const int       MyProc   = ParallelDescriptor::MyProc();
    const int       NProcs   = ParallelDescriptor::NProcs();
    const int       IOProc   = ParallelDescriptor::IOProcessorNumber();
    const auto      strttime = amrex::second();
    const Geometry& geom     = Geom(0);

    Real r, x, len[AMREX_SPACEDIM] = { AMREX_D_DECL(geom.ProbLength(0),
                                           geom.ProbLength(1),
                                           geom.ProbLength(2)) };

    // We will enforce that the particles are within the containing_bx.
    // If containing_bx is not passed in, it defaults to the full domain.
    if (!containing_bx.ok()) { containing_bx = geom.ProbDomain(); }

    // containing_bx is assumed to lie within the domain.
    if (!geom.ProbDomain().contains(containing_bx))
    {
        containing_bx.setLo(geom.ProbLo());
        containing_bx.setHi(geom.ProbHi());
    }

    const Real* xlo = containing_bx.lo();
    const Real* xhi = containing_bx.hi();

    amrex::InitRandom(iseed+MyProc);

    if (serialize)
    {
        if(icount*AMREX_SPACEDIM >= std::numeric_limits<int>::max())
        {
            amrex::Abort(
                "InitRandom has serialize=true, but this would cause too much "
                "particle data to be sent from IOProc. Set serialize=false, "
                "or use fewer than " +
                std::to_string(
                    amrex::Math::ceil(
                        amrex::Real(std::numeric_limits<int>::max()) /
                        amrex::Real(AMREX_SPACEDIM)
                    )
                ) + " particles."
            );
        }
        //
        // We'll let IOProc generate the particles so we get the same