PABLO_example_00003.cpp

2D smoothing data using PABLO

2D smoothing data using PABLOThis example shows how to use PABLO's methods to find neighboring quadrants of a specified element. Neighbors search can be performed through faces, edges and nodes (in 2D case, only faces and nodes).

In this example a 2D octree is refined four times and then a set of data is assigned to the mesh using STL vectors. More specifically, an integer equal to 1 is assigned uniformly to all quadrants within a circle, and 0 to the remaining quadrants. In this example neighbor-search is used to perform a simple moving-average-smoothing procedure of the data.

The obtained results show the time-evolution of data over 25 smoothing iterations.

To run: ./PABLO_example_00003
To see the result visit: PABLO website

/*---------------------------------------------------------------------------*\
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 *  Copyright (C) 2015-2021 OPTIMAD engineering Srl
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 *  bitpit is free software: you can redistribute it and/or modify it
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 *  as published by the Free Software Foundation.
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 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 *  License for more details.
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 *  You should have received a copy of the GNU Lesser General Public License
 *  along with bitpit. If not, see <http://www.gnu.org/licenses/>.
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#if BITPIT_ENABLE_MPI==1
#include <mpi.h>
#endif
 
#include "bitpit_PABLO.hpp"
 
using namespace std;
using namespace bitpit;
 
// =================================================================================== //
// =================================================================================== //
 
void run()
{
    int iter = 0;
 
    PabloUniform pablo3(2);
 
    for (iter=1; iter<5; iter++){
        pablo3.adaptGlobalRefine();
    }
 
    double xc, yc;
    xc = yc = 0.5;
    double radius = 0.25;
 
    uint32_t nocts = pablo3.getNumOctants();
    vector<double> oct_data(nocts, 0.0);
 
    for (unsigned int i=0; i<nocts; i++){
        vector<array<double,3> > nodes = pablo3.getNodes(i);
        for (int j=0; j<4; j++){
            double x = nodes[j][0];
            double y = nodes[j][1];
            if ((pow((x-xc),2.0)+pow((y-yc),2.0) <= pow(radius,2.0))){
                oct_data[i] = 1.0;
            }
        }
    }
 
    iter = 0;
    pablo3.updateConnectivity();
    pablo3.writeTest("pablo00003_iter"+to_string(static_cast<unsigned long long>(iter)), oct_data);
 
    int start = 1;
    for (iter=start; iter<start+25; iter++){
        vector<double> oct_data_smooth(nocts, 0.0);
        vector<uint32_t> neigh, neigh_t;
        vector<bool> isghost, isghost_t;
        uint8_t iface, nfaces;
        int codim;
        for (unsigned int i=0; i<nocts; i++){
            neigh.clear();
            isghost.clear();
 
            for (codim=1; codim<3; codim++){
                if (codim == 1){
                    nfaces = 4;
                }
                else if (codim == 2){
                    nfaces = 4;
                }
                for (iface=0; iface<nfaces; iface++){
                    pablo3.findNeighbours(i,iface,codim,neigh_t,isghost_t);
                    neigh.insert(neigh.end(), neigh_t.begin(), neigh_t.end());
                    isghost.insert(isghost.end(), isghost_t.begin(), isghost_t.end());
                }
            }
 
            oct_data_smooth[i] = oct_data[i]/(neigh.size()+1);
            for (unsigned int j=0; j<neigh.size(); j++){
                if (isghost[j]){
                }
                else{
                    oct_data_smooth[i] += oct_data[neigh[j]]/(neigh.size()+1);
                }
            }
        }
 
        pablo3.updateConnectivity();
        pablo3.writeTest("pablo00003_iter"+to_string(static_cast<unsigned long long>(iter)), oct_data_smooth);
 
        oct_data = oct_data_smooth;
    }
}
 
int main(int argc, char *argv[])
{
#if BITPIT_ENABLE_MPI==1
    MPI_Init(&argc,&argv);
#else
    BITPIT_UNUSED(argc);
    BITPIT_UNUSED(argv);
#endif
 
    int nProcs;
    int rank;
#if BITPIT_ENABLE_MPI==1
    MPI_Comm_size(MPI_COMM_WORLD, &nProcs);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
#else
    nProcs = 1;
    rank   = 0;
#endif
 
    // Initialize the logger
    log::manager().initialize(log::MODE_SEPARATE, false, nProcs, rank);
    log::cout() << log::fileVerbosity(log::LEVEL_INFO);
    log::cout() << log::disableConsole();
 
    // Run the example
    try {
        run();
    } catch (const std::exception &exception) {
        log::cout() << exception.what();
        exit(1);
    }
 
#if BITPIT_ENABLE_MPI==1
    MPI_Finalize();
#endif
}