void
writePlotFile (const std::string& dir,
const MultiFab& mf,
const Geometry& geom)
{
//
// Only let 64 CPUs be writing at any one time.
//
VisMF::SetNOutFiles(64);
//
// Only the I/O processor makes the directory if it doesn't already exist.
//
if (ParallelDescriptor::IOProcessor())
if (!BoxLib::UtilCreateDirectory(dir, 0755))
BoxLib::CreateDirectoryFailed(dir);
//
// Force other processors to wait till directory is built.
//
ParallelDescriptor::Barrier();
std::string HeaderFileName = dir + "/Header";
VisMF::IO_Buffer io_buffer(VisMF::IO_Buffer_Size);
std::ofstream HeaderFile;
HeaderFile.rdbuf()->pubsetbuf(io_buffer.dataPtr(), io_buffer.size());
if (ParallelDescriptor::IOProcessor())
{
//
// Only the IOProcessor() writes to the header file.
//
HeaderFile.open(HeaderFileName.c_str(), std::ios::out|std::ios::trunc|std::ios::binary);
if (!HeaderFile.good())
BoxLib::FileOpenFailed(HeaderFileName);
HeaderFile << "NavierStokes-V1.1\n";
HeaderFile << mf.nComp() << '\n';
for (int ivar = 1; ivar <= mf.nComp(); ivar++) {
HeaderFile << "Variable " << ivar << "\n";
}
HeaderFile << BL_SPACEDIM << '\n';
HeaderFile << 0 << '\n';
HeaderFile << 0 << '\n';
for (int i = 0; i < BL_SPACEDIM; i++)
HeaderFile << geom.ProbLo(i) << ' ';
HeaderFile << '\n';
for (int i = 0; i < BL_SPACEDIM; i++)
HeaderFile << geom.ProbHi(i) << ' ';
HeaderFile << '\n';
HeaderFile << '\n';
HeaderFile << geom.Domain() << ' ';
HeaderFile << '\n';
HeaderFile << 0 << ' ';
HeaderFile << '\n';
for (int k = 0; k < BL_SPACEDIM; k++)
HeaderFile << geom.CellSize()[k] << ' ';
HeaderFile << '\n';
HeaderFile << geom.Coord() << '\n';
HeaderFile << "0\n";
}
// Build the directory to hold the MultiFab at this level.
// The name is relative to the directory containing the Header file.
//
static const std::string BaseName = "/Cell";
std::string Level = BoxLib::Concatenate("Level_", 0, 1);
//
// Now for the full pathname of that directory.
//
std::string FullPath = dir;
if (!FullPath.empty() && FullPath[FullPath.length()-1] != '/')
FullPath += '/';
FullPath += Level;
//
// Only the I/O processor makes the directory if it doesn't already exist.
//
if (ParallelDescriptor::IOProcessor())
if (!BoxLib::UtilCreateDirectory(FullPath, 0755))
BoxLib::CreateDirectoryFailed(FullPath);
//
// Force other processors to wait till directory is built.
//
ParallelDescriptor::Barrier();
if (ParallelDescriptor::IOProcessor())
{
HeaderFile << 0 << ' ' << mf.boxArray().size() << ' ' << 0 << '\n';
HeaderFile << 0 << '\n';
for (int i = 0; i < mf.boxArray().size(); ++i)
{
RealBox loc = RealBox(mf.boxArray()[i],geom.CellSize(),geom.ProbLo());
for (int n = 0; n < BL_SPACEDIM; n++)
HeaderFile << loc.lo(n) << ' ' << loc.hi(n) << '\n';
}
std::string PathNameInHeader = Level;
PathNameInHeader += BaseName;
HeaderFile << PathNameInHeader << '\n';
}
//
// Use the Full pathname when naming the MultiFab.
//
std::string TheFullPath = FullPath;
TheFullPath += BaseName;
VisMF::Write(mf,TheFullPath);
}
void main_main ()
{
// What time is it now? We'll use this to compute total run time.
Real strt_time = ParallelDescriptor::second();
std::cout << std::setprecision(15);
int n_cell, max_grid_size, nsteps, plot_int, is_periodic[BL_SPACEDIM];
// Boundary conditions
Array<int> lo_bc(BL_SPACEDIM), hi_bc(BL_SPACEDIM);
// inputs parameters
{
// ParmParse is way of reading inputs from the inputs file
ParmParse pp;
// We need to get n_cell from the inputs file - this is the number of cells on each side of
// a square (or cubic) domain.
pp.get("n_cell",n_cell);
// Default nsteps to 0, allow us to set it to something else in the inputs file
pp.get("max_grid_size",max_grid_size);
// Default plot_int to 1, allow us to set it to something else in the inputs file
// If plot_int < 0 then no plot files will be written
plot_int = 1;
pp.query("plot_int",plot_int);
// Default nsteps to 0, allow us to set it to something else in the inputs file
nsteps = 0;
pp.query("nsteps",nsteps);
// Boundary conditions - default is periodic (INT_DIR)
for (int i = 0; i < BL_SPACEDIM; ++i)
{
lo_bc[i] = hi_bc[i] = INT_DIR; // periodic boundaries are interior boundaries
}
pp.queryarr("lo_bc",lo_bc,0,BL_SPACEDIM);
pp.queryarr("hi_bc",hi_bc,0,BL_SPACEDIM);
}
// make BoxArray and Geometry
BoxArray ba;
Geometry geom;
{
IntVect dom_lo(IntVect(D_DECL(0,0,0)));
IntVect dom_hi(IntVect(D_DECL(n_cell-1, n_cell-1, n_cell-1)));
Box domain(dom_lo, dom_hi);
// Initialize the boxarray "ba" from the single box "bx"
ba.define(domain);
// Break up boxarray "ba" into chunks no larger than "max_grid_size" along a direction
ba.maxSize(max_grid_size);
// This defines the physical size of the box. Right now the box is [-1,1] in each direction.
RealBox real_box;
for (int n = 0; n < BL_SPACEDIM; n++) {
real_box.setLo(n,-1.0);
real_box.setHi(n, 1.0);
}
// This says we are using Cartesian coordinates
int coord = 0;
// This sets the boundary conditions to be doubly or triply periodic
int is_periodic[BL_SPACEDIM];
for (int i = 0; i < BL_SPACEDIM; i++)
{
is_periodic[i] = 0;
if (lo_bc[i] == 0 && hi_bc[i] == 0) {
is_periodic[i] = 1;
}
}
// This defines a Geometry object
geom.define(domain,&real_box,coord,is_periodic);
}
// Boundary conditions
PhysBCFunct physbcf;
BCRec bcr(&lo_bc[0], &hi_bc[0]);
physbcf.define(geom, bcr, BndryFunctBase(phifill)); // phifill is a fortran function
// define dx[]
const Real* dx = geom.CellSize();
// Nghost = number of ghost cells for each array
int Nghost = 1;
// Ncomp = number of components for each array
int Ncomp = 1;
// time = starting time in the simulation
Real time = 0.0;
// we allocate two phi multifabs; one will store the old state, the other the new
// we swap the indices each time step to avoid copies of new into old
PArray<MultiFab> phi(2, PArrayManage);
phi.set(0, new MultiFab(ba, Ncomp, Nghost));
phi.set(1, new MultiFab(ba, Ncomp, Nghost));
// Initialize both to zero (just because)
phi[0].setVal(0.0);
phi[1].setVal(0.0);
// Initialize phi[init_index] by calling a Fortran routine.
// MFIter = MultiFab Iterator
int init_index = 0;
for ( MFIter mfi(phi[init_index]); mfi.isValid(); ++mfi )
{
const Box& bx = mfi.validbox();
init_phi(phi[init_index][mfi].dataPtr(),
bx.loVect(), bx.hiVect(), &Nghost,
geom.CellSize(), geom.ProbLo(), geom.ProbHi());
}
// compute the time step
Real dt = 0.9*dx[0]*dx[0] / (2.0*BL_SPACEDIM);
// Write a plotfile of the initial data if plot_int > 0 (plot_int was defined in the inputs file)
if (plot_int > 0)
{
int n = 0;
const std::string& pltfile = BoxLib::Concatenate("plt",n,5);
writePlotFile(pltfile, phi[init_index], geom, time);
}
// build the flux multifabs
PArray<MultiFab> flux(BL_SPACEDIM, PArrayManage);
for (int dir = 0; dir < BL_SPACEDIM; dir++)
{
// flux(dir) has one component, zero ghost cells, and is nodal in direction dir
BoxArray edge_ba = ba;
edge_ba.surroundingNodes(dir);
flux.set(dir, new MultiFab(edge_ba, 1, 0));
}
int old_index = init_index;
for (int n = 1; n <= nsteps; n++, old_index = 1 - old_index)
{
int new_index = 1 - old_index;
// new_phi = old_phi + dt * (something)
advance(phi[old_index], phi[new_index], flux, time, dt, geom, physbcf, bcr);
time = time + dt;
// Tell the I/O Processor to write out which step we're doing
if (ParallelDescriptor::IOProcessor())
std::cout << "Advanced step " << n << std::endl;
// Write a plotfile of the current data (plot_int was defined in the inputs file)
if (plot_int > 0 && n%plot_int == 0)
{
const std::string& pltfile = BoxLib::Concatenate("plt",n,5);
writePlotFile(pltfile, phi[new_index], geom, time);
}
}
// Call the timer again and compute the maximum difference between the start time and stop time
// over all processors
Real stop_time = ParallelDescriptor::second() - strt_time;
const int IOProc = ParallelDescriptor::IOProcessorNumber();
ParallelDescriptor::ReduceRealMax(stop_time,IOProc);
// Tell the I/O Processor to write out the "run time"
if (ParallelDescriptor::IOProcessor()) {
std::cout << "Run time = " << stop_time << std::endl;
}
}