int main(int argc,char **argv)
{
TS ts; /* ODE integrator */
Vec U,V; /* solution will be stored here */
Vec F; /* residual vector */
Mat J; /* Jacobian matrix */
PetscMPIInt rank;
PetscScalar *u,*v;
AppCtx app;
PetscInt direction[2];
PetscBool terminate[2];
TSAdapt adapt;
PetscErrorCode ierr;
ierr = PetscInitialize(&argc,&argv,NULL,help);CHKERRQ(ierr);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
app.Cd = 0.0;
app.Cr = 0.9;
app.bounces = 0;
app.maxbounces = 10;
ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"ex44 options","");CHKERRQ(ierr);
ierr = PetscOptionsReal("-Cd","Drag coefficient","",app.Cd,&app.Cd,NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-Cr","Restitution coefficient","",app.Cr,&app.Cr,NULL);CHKERRQ(ierr);
ierr = PetscOptionsInt("-maxbounces","Maximum number of bounces","",app.maxbounces,&app.maxbounces,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
/*ierr = TSSetSaveTrajectory(ts);CHKERRQ(ierr);*/
ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
ierr = TSSetType(ts,TSALPHA2);CHKERRQ(ierr);
ierr = TSSetDuration(ts,PETSC_MAX_INT,PETSC_MAX_REAL);CHKERRQ(ierr);
ierr = TSSetTimeStep(ts,0.1);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
ierr = TSAdaptSetStepLimits(adapt,0.0,0.5);CHKERRQ(ierr);
direction[0] = -1; terminate[0] = PETSC_FALSE;
direction[1] = -1; terminate[1] = PETSC_TRUE;
ierr = TSSetEventHandler(ts,2,direction,terminate,Event,PostEvent,&app);CHKERRQ(ierr);
ierr = MatCreateAIJ(PETSC_COMM_WORLD,1,1,PETSC_DECIDE,PETSC_DECIDE,1,NULL,0,NULL,&J);CHKERRQ(ierr);
ierr = MatSetFromOptions(J);CHKERRQ(ierr);
ierr = MatSetUp(J);CHKERRQ(ierr);
ierr = MatCreateVecs(J,NULL,&F);CHKERRQ(ierr);
ierr = TSSetI2Function(ts,F,I2Function,&app);CHKERRQ(ierr);
ierr = TSSetI2Jacobian(ts,J,J,I2Jacobian,&app);CHKERRQ(ierr);
ierr = VecDestroy(&F);CHKERRQ(ierr);
ierr = MatDestroy(&J);CHKERRQ(ierr);
ierr = TSGetI2Jacobian(ts,&J,NULL,NULL,NULL);CHKERRQ(ierr);
ierr = MatCreateVecs(J,&U,NULL);CHKERRQ(ierr);
ierr = MatCreateVecs(J,&V,NULL);CHKERRQ(ierr);
ierr = VecGetArray(U,&u);CHKERRQ(ierr);
ierr = VecGetArray(V,&v);CHKERRQ(ierr);
u[0] = 5.0*rank; v[0] = 20.0;
ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
ierr = VecRestoreArray(V,&v);CHKERRQ(ierr);
ierr = TS2SetSolution(ts,U,V);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
ierr = TSSolve(ts,NULL);CHKERRQ(ierr);
ierr = VecDestroy(&U);CHKERRQ(ierr);
ierr = VecDestroy(&V);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
int main(int argc, char *argv[])
{
PetscMPIInt size;
TS ts;
Vec R;
Mat J;
Vec U,V;
PetscScalar *u,*v;
UserParams user = {/*Omega=*/ 1, /*Xi=*/ 0, /*u0=*/ 1, /*,v0=*/ 0};
PetscErrorCode ierr;
ierr = PetscInitialize(&argc,&argv,NULL,help);CHKERRQ(ierr);
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
if (size > 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Only for sequential runs");
ierr = PetscOptionsBegin(PETSC_COMM_SELF,"","ex43 options","");CHKERRQ(ierr);
ierr = PetscOptionsReal("-frequency","Natual frequency",__FILE__,user.Omega,&user.Omega,NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-damping","Damping coefficient",__FILE__,user.Xi,&user.Xi,NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-initial_u","Initial displacement",__FILE__,user.u0,&user.u0,NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-initial_v","Initial velocity",__FILE__,user.v0,&user.v0,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
ierr = TSCreate(PETSC_COMM_SELF,&ts);CHKERRQ(ierr);
ierr = TSSetType(ts,TSALPHA2);CHKERRQ(ierr);
ierr = TSSetMaxTime(ts,5*(2*PETSC_PI));CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
ierr = TSSetTimeStep(ts,0.01);CHKERRQ(ierr);
ierr = VecCreateSeq(PETSC_COMM_SELF,1,&R);CHKERRQ(ierr);
ierr = VecSetUp(R);CHKERRQ(ierr);
ierr = MatCreateSeqDense(PETSC_COMM_SELF,1,1,NULL,&J);CHKERRQ(ierr);
ierr = MatSetUp(J);CHKERRQ(ierr);
if (user.Xi) {
ierr = TSSetI2Function(ts,R,Residual2,&user);CHKERRQ(ierr);
ierr = TSSetI2Jacobian(ts,J,J,Tangent2,&user);CHKERRQ(ierr);
} else {
ierr = TSSetIFunction(ts,R,Residual1,&user);CHKERRQ(ierr);
ierr = TSSetIJacobian(ts,J,J,Tangent1,&user);CHKERRQ(ierr);
}
ierr = VecDestroy(&R);CHKERRQ(ierr);
ierr = MatDestroy(&J);CHKERRQ(ierr);
ierr = TSSetSolutionFunction(ts,Solution,&user);CHKERRQ(ierr);
ierr = VecCreateSeq(PETSC_COMM_SELF,1,&U);CHKERRQ(ierr);
ierr = VecCreateSeq(PETSC_COMM_SELF,1,&V);CHKERRQ(ierr);
ierr = VecGetArray(U,&u);CHKERRQ(ierr);
ierr = VecGetArray(V,&v);CHKERRQ(ierr);
u[0] = user.u0;
v[0] = user.v0;
ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
ierr = VecRestoreArray(V,&v);CHKERRQ(ierr);
ierr = TS2SetSolution(ts,U,V);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
ierr = TSSolve(ts,NULL);CHKERRQ(ierr);
ierr = VecDestroy(&U);CHKERRQ(ierr);
ierr = VecDestroy(&V);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}