How to restart MercuryDPM driver codes

Restart your code in three steps:

• Replace the simple solve command in the main function by solve(argc, argv), so you can read in command-line arguments.
• All DPMBase variables can be read from the restart file, but your Driver code might have new variables defined; so you have to set these variables yourself. For this there is the function DPMBase::actionsOnRestart, where you can reset your own variables in case of a restart.
• Run your code with the command-line argument "-r" to force a restart; "-tmax [time]" can be used to reset final time.

Below is a simple case of how to modify your code to be restart-ready:

#include "DPMBase.h"
#include "Walls/InfiniteWall.h"
#include "Species/LinearViscoelasticSpecies.h"
 
class FreeFall : public DPMBase{
public:
 
    // Set species, particles, boundaries, walls here
    void setupInitialConditions() override
    {
        LinearViscoelasticSpecies s;
        s.setStiffness(1e5);
        s.setDissipation(0.01);
        s.setDensity(2e3);
        auto sp = speciesHandler.copyAndAddObject(s);
 
        InfiniteWall w0;
        w0.setSpecies(speciesHandler.getObject(0));
        w0.set(Vec3D(0,0,-1), Vec3D(0, 0, 0));
        wallHandler.copyAndAddObject(w0);
 
        SphericalParticle p0;
        p0.setSpecies(speciesHandler.getObject(0));
        p0.setPosition(Vec3D(0,0,getZMax()-1e-3));
        p0.setRadius(1e-3);
        particleHandler.copyAndAddObject(p0);
    }
 
    //this function replaces setupInitialConditions in case of a restart
    //if you have problem-specific variables, set them here
    void actionsOnRestart() override
    {
    }
 
};
 
int main(int argc, char *argv[])
{
    //Start off my solving the default problem
    FreeFall dpm;
 
    //set FreeFall-specific parameters here
    dpm.setName("FreeFallRestart");
    dpm.setSaveCount(1000);
    dpm.setTimeStep(1e-6);
    dpm.setTimeMax(0.5);
    dpm.setDomain(Vec3D(-1e-3,-1e-3,0e-3),Vec3D(1e-3,1e-3,10e-3));
    dpm.setGravity(Vec3D(0,0,-9.8));
 
    //restart and run until final time 1, using command line arguments:
    // ./freeFallRestart -r -tmax 1
    dpm.solve(argc,argv);
    return 0;
}