int main(int argc,char **argv) { TS ts; /* ODE integrator */ Vec U; /* solution will be stored here */ Mat A; /* Jacobian matrix */ PetscErrorCode ierr; PetscMPIInt size; PetscInt n = 3; AppCtx ctx; PetscScalar *u; /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Initialize program - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscInitialize(&argc,&argv,(char*)0,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"); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create necessary matrix and vectors - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,n,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = MatSetUp(A);CHKERRQ(ierr); ierr = MatGetVecs(A,&U,NULL);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set runtime options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Reaction options","");CHKERRQ(ierr); { ctx.k = .9; ierr = PetscOptionsScalar("-k","Reaction coefficient","",ctx.k,&ctx.k,NULL);CHKERRQ(ierr); ierr = VecDuplicate(U,&ctx.initialsolution);CHKERRQ(ierr); ierr = VecGetArray(ctx.initialsolution,&u);CHKERRQ(ierr); u[0] = 1; u[1] = .7; u[2] = 0; ierr = VecRestoreArray(ctx.initialsolution,&u);CHKERRQ(ierr); ierr = PetscOptionsVec("-initial","Initial values","",ctx.initialsolution,NULL);CHKERRQ(ierr); } ierr = PetscOptionsEnd();CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create timestepping solver context - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr); ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr); ierr = TSSetType(ts,TSROSW);CHKERRQ(ierr); ierr = TSSetIFunction(ts,NULL,(TSIFunction) IFunction,&ctx);CHKERRQ(ierr); ierr = TSSetIJacobian(ts,A,A,(TSIJacobian)IJacobian,&ctx);CHKERRQ(ierr); ierr = TSSetSolutionFunction(ts,(TSSolutionFunction)Solution,&ctx);CHKERRQ(ierr); { DM dm; void *ptr; ierr = TSGetDM(ts,&dm);CHKERRQ(ierr); ierr = PetscDLSym(NULL,"IFunctionView",&ptr);CHKERRQ(ierr); ierr = PetscDLSym(NULL,"IFunctionLoad",&ptr);CHKERRQ(ierr); ierr = DMTSSetIFunctionSerialize(dm,(PetscErrorCode (*)(void*,PetscViewer))IFunctionView,(PetscErrorCode (*)(void**,PetscViewer))IFunctionLoad);CHKERRQ(ierr); ierr = DMTSSetIJacobianSerialize(dm,(PetscErrorCode (*)(void*,PetscViewer))IFunctionView,(PetscErrorCode (*)(void**,PetscViewer))IFunctionLoad);CHKERRQ(ierr); } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set initial conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = Solution(ts,0,U,&ctx);CHKERRQ(ierr); ierr = TSSetSolution(ts,U);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set solver options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSetDuration(ts,1000,20.0);CHKERRQ(ierr); ierr = TSSetInitialTimeStep(ts,0.0,.001);CHKERRQ(ierr); ierr = TSSetFromOptions(ts);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Solve nonlinear system - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSolve(ts,U);CHKERRQ(ierr); ierr = TSView(ts,PETSC_VIEWER_BINARY_WORLD);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Free work space. All PETSc objects should be destroyed when they are no longer needed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = VecDestroy(&ctx.initialsolution);CHKERRQ(ierr); ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = VecDestroy(&U);CHKERRQ(ierr); ierr = TSDestroy(&ts);CHKERRQ(ierr); ierr = PetscFinalize(); return(0); }
int main(int argc,char **argv) { TS ts; /* ODE integrator */ Vec U; /* solution will be stored here */ Mat A; /* Jacobian matrix */ PetscErrorCode ierr; PetscMPIInt size; PetscInt n = 2; AppCtx ctx; PetscScalar *u; /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Initialize program - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscInitialize(&argc,&argv,(char*)0,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"); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create necessary matrix and vectors - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,n,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = MatSetUp(A);CHKERRQ(ierr); ierr = MatGetVecs(A,&U,NULL);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set runtime options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Reaction options","");CHKERRQ(ierr); { ctx.omega_s = 1.0; ierr = PetscOptionsScalar("-omega_s","","",ctx.omega_s,&ctx.omega_s,NULL);CHKERRQ(ierr); ctx.H = 1.0; ierr = PetscOptionsScalar("-H","","",ctx.H,&ctx.H,NULL);CHKERRQ(ierr); ctx.E = 1.0; ierr = PetscOptionsScalar("-E","","",ctx.E,&ctx.E,NULL);CHKERRQ(ierr); ctx.V = 1.0; ierr = PetscOptionsScalar("-V","","",ctx.V,&ctx.V,NULL);CHKERRQ(ierr); ctx.X = 1.0; ierr = PetscOptionsScalar("-X","","",ctx.X,&ctx.X,NULL);CHKERRQ(ierr); ierr = VecGetArray(U,&u);CHKERRQ(ierr); u[0] = 1; u[1] = .7; ierr = VecRestoreArray(U,&u);CHKERRQ(ierr); ierr = PetscOptionsVec("-initial","Initial values","",U,NULL);CHKERRQ(ierr); } ierr = PetscOptionsEnd();CHKERRQ(ierr); ierr = PetscRandomCreate(PETSC_COMM_WORLD,&ctx.rand);CHKERRQ(ierr); ierr = PetscRandomSetFromOptions(ctx.rand);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Create timestepping solver context - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr); ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr); ierr = TSSetType(ts,TSROSW);CHKERRQ(ierr); ierr = TSSetIFunction(ts,NULL,(TSIFunction) IFunction,&ctx);CHKERRQ(ierr); ierr = TSSetIJacobian(ts,A,A,(TSIJacobian)IJacobian,&ctx);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set initial conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSetSolution(ts,U);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Set solver options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSetDuration(ts,100000,2000.0);CHKERRQ(ierr); ierr = TSSetInitialTimeStep(ts,0.0,.001);CHKERRQ(ierr); ierr = TSSetFromOptions(ts);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Solve nonlinear system - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = TSSolve(ts,U);CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Free work space. All PETSc objects should be destroyed when they are no longer needed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = VecDestroy(&U);CHKERRQ(ierr); ierr = TSDestroy(&ts);CHKERRQ(ierr); ierr = PetscRandomDestroy(&ctx.rand);CHKERRQ(ierr); ierr = PetscFinalize(); return(0); }