virtual void setStepLimits(Real dtmin,Real dtmax) {
PetscErrorCode ierr;
TSAdapt adapt;
ierr = TSGetAdapt(this->_ts,&adapt);
CHKERRABORT(libMesh::COMM_WORLD,ierr);
ierr = TSAdaptSetStepLimits(adapt,dtmin,dtmax);
CHKERRABORT(libMesh::COMM_WORLD,ierr);
}
/*
TSAdaptSetFromOptions - Sets various TSAdapt parameters from user options.
Collective on TSAdapt
Input Parameter:
. adapt - the TSAdapt context
Options Database Keys:
+ -ts_adapt_type <type> - algorithm to use for adaptivity
. -ts_adapt_always_accept - always accept steps regardless of error/stability goals
. -ts_adapt_safety <safety> - safety factor relative to target error/stability goal
. -ts_adapt_reject_safety <safety> - extra safety factor to apply if the last step was rejected
. -ts_adapt_clip <low,high> - admissible time step decrease and increase factors
. -ts_adapt_dt_min <min> - minimum timestep to use
. -ts_adapt_dt_max <max> - maximum timestep to use
. -ts_adapt_scale_solve_failed <scale> - scale timestep by this factor if a solve fails
. -ts_adapt_wnormtype <2 or infinity> - type of norm for computing error estimates
- -ts_adapt_time_step_increase_delay - number of timesteps to delay increasing the time step after it has been decreased due to failed solver
Level: advanced
Notes:
This function is automatically called by TSSetFromOptions()
.keywords: TS, TSGetAdapt(), TSAdaptSetType(), TSAdaptSetStepLimits()
.seealso: TSGetAdapt(), TSAdaptSetType(), TSAdaptSetAlwaysAccept(), TSAdaptSetSafety(),
TSAdaptSetClip(), TSAdaptSetStepLimits(), TSAdaptSetMonitor()
*/
PetscErrorCode TSAdaptSetFromOptions(PetscOptionItems *PetscOptionsObject,TSAdapt adapt)
{
PetscErrorCode ierr;
char type[256] = TSADAPTBASIC;
PetscReal safety,reject_safety,clip[2],hmin,hmax;
PetscBool set,flg;
PetscInt two;
PetscFunctionBegin;
PetscValidHeaderSpecific(adapt,TSADAPT_CLASSID,1);
/* This should use PetscOptionsBegin() if/when this becomes an object used outside of TS, but currently this
* function can only be called from inside TSSetFromOptions() */
ierr = PetscOptionsHead(PetscOptionsObject,"TS Adaptivity options");CHKERRQ(ierr);
ierr = PetscOptionsFList("-ts_adapt_type","Algorithm to use for adaptivity","TSAdaptSetType",TSAdaptList,((PetscObject)adapt)->type_name ? ((PetscObject)adapt)->type_name : type,type,sizeof(type),&flg);CHKERRQ(ierr);
if (flg || !((PetscObject)adapt)->type_name) {
ierr = TSAdaptSetType(adapt,type);CHKERRQ(ierr);
}
ierr = PetscOptionsBool("-ts_adapt_always_accept","Always accept the step","TSAdaptSetAlwaysAccept",adapt->always_accept,&flg,&set);CHKERRQ(ierr);
if (set) {ierr = TSAdaptSetAlwaysAccept(adapt,flg);CHKERRQ(ierr);}
safety = adapt->safety; reject_safety = adapt->reject_safety;
ierr = PetscOptionsReal("-ts_adapt_safety","Safety factor relative to target error/stability goal","TSAdaptSetSafety",safety,&safety,&set);CHKERRQ(ierr);
ierr = PetscOptionsReal("-ts_adapt_reject_safety","Extra safety factor to apply if the last step was rejected","TSAdaptSetSafety",reject_safety,&reject_safety,&flg);CHKERRQ(ierr);
if (set || flg) {ierr = TSAdaptSetSafety(adapt,safety,reject_safety);CHKERRQ(ierr);}
two = 2; clip[0] = adapt->clip[0]; clip[1] = adapt->clip[1];
ierr = PetscOptionsRealArray("-ts_adapt_clip","Admissible decrease/increase factor in step size","TSAdaptSetClip",clip,&two,&set);CHKERRQ(ierr);
if (set && (two != 2)) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_OUTOFRANGE,"Must give exactly two values to -ts_adapt_clip");
if (set) {ierr = TSAdaptSetClip(adapt,clip[0],clip[1]);CHKERRQ(ierr);}
hmin = adapt->dt_min; hmax = adapt->dt_max;
ierr = PetscOptionsReal("-ts_adapt_dt_min","Minimum time step considered","TSAdaptSetStepLimits",hmin,&hmin,&set);CHKERRQ(ierr);
ierr = PetscOptionsReal("-ts_adapt_dt_max","Maximum time step considered","TSAdaptSetStepLimits",hmax,&hmax,&flg);CHKERRQ(ierr);
if (set || flg) {ierr = TSAdaptSetStepLimits(adapt,hmin,hmax);CHKERRQ(ierr);}
ierr = PetscOptionsReal("-ts_adapt_max_ignore","Adaptor ignores (absolute) solution values smaller than this value","",adapt->ignore_max,&adapt->ignore_max,&set);CHKERRQ(ierr);
ierr = PetscOptionsBool("-ts_adapt_glee_use_local","GLEE adaptor uses local error estimation for step control","",adapt->glee_use_local,&adapt->glee_use_local,&set);CHKERRQ(ierr);
ierr = PetscOptionsReal("-ts_adapt_scale_solve_failed","Scale step by this factor if solve fails","",adapt->scale_solve_failed,&adapt->scale_solve_failed,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnum("-ts_adapt_wnormtype","Type of norm computed for error estimation","",NormTypes,(PetscEnum)adapt->wnormtype,(PetscEnum*)&adapt->wnormtype,NULL);CHKERRQ(ierr);
if (adapt->wnormtype != NORM_2 && adapt->wnormtype != NORM_INFINITY) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_SUP,"Only 2-norm and infinite norm supported");
ierr = PetscOptionsInt("-ts_adapt_time_step_increase_delay","Number of timesteps to delay increasing the time step after it has been decreased due to failed solver","TSAdaptSetTimeStepIncreaseDelay",adapt->timestepjustdecreased_delay,&adapt->timestepjustdecreased_delay,NULL);CHKERRQ(ierr);
ierr = PetscOptionsBool("-ts_adapt_monitor","Print choices made by adaptive controller","TSAdaptSetMonitor",adapt->monitor ? PETSC_TRUE : PETSC_FALSE,&flg,&set);CHKERRQ(ierr);
if (set) {ierr = TSAdaptSetMonitor(adapt,flg);CHKERRQ(ierr);}
if (adapt->ops->setfromoptions) {ierr = (*adapt->ops->setfromoptions)(PetscOptionsObject,adapt);CHKERRQ(ierr);}
ierr = PetscOptionsTail();CHKERRQ(ierr);
PetscFunctionReturn(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 rank;
PetscInt n = 2;
PetscScalar *u;
PetscInt direction=-1;
PetscBool terminate=PETSC_FALSE;
TSAdapt adapt;
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Initialize program
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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 = MatSetType(A,MATDENSE);CHKERRQ(ierr);
ierr = MatSetFromOptions(A);CHKERRQ(ierr);
ierr = MatSetUp(A);CHKERRQ(ierr);
ierr = MatCreateVecs(A,&U,NULL);CHKERRQ(ierr);
ierr = VecGetArray(U,&u);CHKERRQ(ierr);
u[0] = 1.0*rank;
u[1] = 20.0;
ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create timestepping solver context
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
ierr = TSSetSaveTrajectory(ts);CHKERRQ(ierr);
ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
ierr = TSSetType(ts,TSROSW);CHKERRQ(ierr);
ierr = TSSetIFunction(ts,NULL,(TSIFunction) IFunction,NULL);CHKERRQ(ierr);
ierr = TSSetIJacobian(ts,A,A,(TSIJacobian)IJacobian,NULL);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set initial conditions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetSolution(ts,U);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set solver options
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetDuration(ts,1000,30.0);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
ierr = TSSetInitialTimeStep(ts,0.0,0.1);CHKERRQ(ierr);
ierr = TSSetEventHandler(ts,1,&direction,&terminate,EventFunction,PostEventFunction,NULL);CHKERRQ(ierr);
/* The adapative time step controller could take very large timesteps resulting in
the same event occuring multiple times in the same interval. A maximum step size
limit is enforced here to avoid this issue.
*/
ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
ierr = TSAdaptSetStepLimits(adapt,0.0,0.5);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Run timestepping solver
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
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 = PetscFinalize();
return ierr;
}
int main(int argc,char **argv)
{
TS ts; /* time integrator */
TSAdapt adapt;
Vec X; /* solution vector */
Mat J; /* Jacobian matrix */
PetscInt steps,maxsteps,ncells,xs,xm,i;
PetscErrorCode ierr;
PetscReal ftime,dt;
char chemfile[PETSC_MAX_PATH_LEN] = "chem.inp",thermofile[PETSC_MAX_PATH_LEN] = "therm.dat";
struct _User user;
TSConvergedReason reason;
PetscBool showsolutions = PETSC_FALSE;
char **snames,*names;
Vec lambda; /* used with TSAdjoint for sensitivities */
ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"Chemistry solver options","");CHKERRQ(ierr);
ierr = PetscOptionsString("-chem","CHEMKIN input file","",chemfile,chemfile,sizeof(chemfile),NULL);CHKERRQ(ierr);
ierr = PetscOptionsString("-thermo","NASA thermo input file","",thermofile,thermofile,sizeof(thermofile),NULL);CHKERRQ(ierr);
user.pressure = 1.01325e5; /* Pascal */
ierr = PetscOptionsReal("-pressure","Pressure of reaction [Pa]","",user.pressure,&user.pressure,NULL);CHKERRQ(ierr);
user.Tini = 1550;
ierr = PetscOptionsReal("-Tini","Initial temperature [K]","",user.Tini,&user.Tini,NULL);CHKERRQ(ierr);
user.diffus = 100;
ierr = PetscOptionsReal("-diffus","Diffusion constant","",user.diffus,&user.diffus,NULL);CHKERRQ(ierr);
ierr = PetscOptionsBool("-draw_solution","Plot the solution for each cell","",showsolutions,&showsolutions,NULL);CHKERRQ(ierr);
user.diffusion = PETSC_TRUE;
ierr = PetscOptionsBool("-diffusion","Have diffusion","",user.diffusion,&user.diffusion,NULL);CHKERRQ(ierr);
user.reactions = PETSC_TRUE;
ierr = PetscOptionsBool("-reactions","Have reactions","",user.reactions,&user.reactions,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
ierr = TC_initChem(chemfile, thermofile, 0, 1.0);TCCHKERRQ(ierr);
user.Nspec = TC_getNspec();
user.Nreac = TC_getNreac();
ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_PERIODIC,-1,user.Nspec+1,1,NULL,&user.dm);CHKERRQ(ierr);
ierr = DMDAGetInfo(user.dm,NULL,&ncells,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
user.dx = 1.0/ncells; /* Set the coordinates of the cell centers; note final ghost cell is at x coordinate 1.0 */
ierr = DMDASetUniformCoordinates(user.dm,0.0,1.0,0.0,1.0,0.0,1.0);CHKERRQ(ierr);
/* set the names of each field in the DMDA based on the species name */
ierr = PetscMalloc1((user.Nspec+1)*LENGTHOFSPECNAME,&names);CHKERRQ(ierr);
ierr = PetscStrcpy(names,"Temp");CHKERRQ(ierr);
TC_getSnames(user.Nspec,names+LENGTHOFSPECNAME);CHKERRQ(ierr);
ierr = PetscMalloc1((user.Nspec+2),&snames);CHKERRQ(ierr);
for (i=0; i<user.Nspec+1; i++) snames[i] = names+i*LENGTHOFSPECNAME;
snames[user.Nspec+1] = NULL;
ierr = DMDASetFieldNames(user.dm,(const char * const *)snames);CHKERRQ(ierr);
ierr = PetscFree(snames);CHKERRQ(ierr);
ierr = PetscFree(names);CHKERRQ(ierr);
ierr = DMCreateMatrix(user.dm,&J);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(user.dm,&X);CHKERRQ(ierr);
ierr = PetscMalloc3(user.Nspec+1,&user.tchemwork,PetscSqr(user.Nspec+1),&user.Jdense,user.Nspec+1,&user.rows);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create timestepping solver context
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
ierr = TSSetDM(ts,user.dm);CHKERRQ(ierr);
ierr = TSSetType(ts,TSARKIMEX);CHKERRQ(ierr);
ierr = TSARKIMEXSetFullyImplicit(ts,PETSC_TRUE);CHKERRQ(ierr);
ierr = TSARKIMEXSetType(ts,TSARKIMEX4);CHKERRQ(ierr);
ierr = TSSetRHSFunction(ts,NULL,FormRHSFunction,&user);CHKERRQ(ierr);
ierr = TSSetRHSJacobian(ts,J,J,FormRHSJacobian,&user);CHKERRQ(ierr);
ftime = 1.0;
maxsteps = 10000;
ierr = TSSetDuration(ts,maxsteps,ftime);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set initial conditions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = FormInitialSolution(ts,X,&user);CHKERRQ(ierr);
ierr = TSSetSolution(ts,X);CHKERRQ(ierr);
dt = 1e-10; /* Initial time step */
ierr = TSSetInitialTimeStep(ts,0.0,dt);CHKERRQ(ierr);
ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
ierr = TSAdaptSetStepLimits(adapt,1e-12,1e-4);CHKERRQ(ierr); /* Also available with -ts_adapt_dt_min/-ts_adapt_dt_max */
ierr = TSSetMaxSNESFailures(ts,-1);CHKERRQ(ierr); /* Retry step an unlimited number of times */
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Pass information to graphical monitoring routine
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
if (showsolutions) {
ierr = DMDAGetCorners(user.dm,&xs,NULL,NULL,&xm,NULL,NULL);CHKERRQ(ierr);
for (i=xs;i<xs+xm;i++) {
ierr = MonitorCell(ts,&user,i);CHKERRQ(ierr);
}
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set runtime options
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set final conditions for sensitivities
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = DMCreateGlobalVector(user.dm,&lambda);CHKERRQ(ierr);
ierr = TSSetCostGradients(ts,1,&lambda,NULL);CHKERRQ(ierr);
ierr = VecSetValue(lambda,0,1.0,INSERT_VALUES);CHKERRQ(ierr);
ierr = VecAssemblyBegin(lambda);CHKERRQ(ierr);
ierr = VecAssemblyEnd(lambda);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Solve ODE
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSolve(ts,X);CHKERRQ(ierr);
ierr = TSGetSolveTime(ts,&ftime);CHKERRQ(ierr);
ierr = TSGetTimeStepNumber(ts,&steps);CHKERRQ(ierr);
ierr = TSGetConvergedReason(ts,&reason);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"%s at time %g after %D steps\n",TSConvergedReasons[reason],(double)ftime,steps);CHKERRQ(ierr);
{
Vec max;
const char * const *names;
PetscInt i;
const PetscReal *bmax;
ierr = TSMonitorEnvelopeGetBounds(ts,&max,NULL);CHKERRQ(ierr);
if (max) {
ierr = TSMonitorLGGetVariableNames(ts,&names);CHKERRQ(ierr);
if (names) {
ierr = VecGetArrayRead(max,&bmax);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_SELF,"Species - maximum mass fraction\n");CHKERRQ(ierr);
for (i=1; i<user.Nspec; i++) {
if (bmax[i] > .01) {ierr = PetscPrintf(PETSC_COMM_SELF,"%s %g\n",names[i],bmax[i]);CHKERRQ(ierr);}
}
ierr = VecRestoreArrayRead(max,&bmax);CHKERRQ(ierr);
}
}
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Free work space.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
TC_reset();
ierr = DMDestroy(&user.dm);CHKERRQ(ierr);
ierr = MatDestroy(&J);CHKERRQ(ierr);
ierr = VecDestroy(&X);CHKERRQ(ierr);
ierr = VecDestroy(&lambda);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = PetscFree3(user.tchemwork,user.Jdense,user.rows);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
void PETSC_STDCALL tsadaptsetsteplimits_(TSAdapt adapt,PetscReal *hmin,PetscReal *hmax, int *__ierr ){
*__ierr = TSAdaptSetStepLimits(
(TSAdapt)PetscToPointer((adapt) ),*hmin,*hmax);
}
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)
{
TS ts; /* ODE integrator */
Vec U; /* solution will be stored here */
PetscErrorCode ierr;
PetscMPIInt size;
PetscInt n = 2;
PetscScalar *u;
AppCtx app;
PetscInt direction[2];
PetscBool terminate[2];
PetscBool rhs_form=PETSC_FALSE,hist=PETSC_TRUE;
TSAdapt adapt;
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Initialize program
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return 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");
app.nbounces = 0;
app.maxbounces = 10;
ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,"ex40 options","");CHKERRQ(ierr);
ierr = PetscOptionsInt("-maxbounces","","",app.maxbounces,&app.maxbounces,NULL);CHKERRQ(ierr);
ierr = PetscOptionsBool("-test_adapthistory","","",hist,&hist,NULL);CHKERRQ(ierr);
ierr = PetscOptionsEnd();CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Create timestepping solver context
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
ierr = TSSetType(ts,TSROSW);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set ODE routines
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
/* Users are advised against the following branching and code duplication.
For problems without a mass matrix like the one at hand, the RHSFunction
(and companion RHSJacobian) interface is enough to support both explicit
and implicit timesteppers. This tutorial example also deals with the
IFunction/IJacobian interface for demonstration and testing purposes. */
ierr = PetscOptionsGetBool(NULL,NULL,"-rhs-form",&rhs_form,NULL);CHKERRQ(ierr);
if (rhs_form) {
ierr = TSSetRHSFunction(ts,NULL,RHSFunction,NULL);CHKERRQ(ierr);
ierr = TSSetRHSJacobian(ts,NULL,NULL,RHSJacobian,NULL);CHKERRQ(ierr);
} else {
Mat A; /* Jacobian matrix */
ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
ierr = MatSetSizes(A,n,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
ierr = MatSetType(A,MATDENSE);CHKERRQ(ierr);
ierr = MatSetFromOptions(A);CHKERRQ(ierr);
ierr = MatSetUp(A);CHKERRQ(ierr);
ierr = TSSetIFunction(ts,NULL,IFunction,NULL);CHKERRQ(ierr);
ierr = TSSetIJacobian(ts,A,A,IJacobian,NULL);CHKERRQ(ierr);
ierr = MatDestroy(&A);CHKERRQ(ierr);
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set initial conditions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = VecCreate(PETSC_COMM_WORLD,&U);CHKERRQ(ierr);
ierr = VecSetSizes(U,n,PETSC_DETERMINE);CHKERRQ(ierr);
ierr = VecSetUp(U);CHKERRQ(ierr);
ierr = VecGetArray(U,&u);CHKERRQ(ierr);
u[0] = 0.0;
u[1] = 20.0;
ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
ierr = TSSetSolution(ts,U);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Set solver options
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSetSaveTrajectory(ts);CHKERRQ(ierr);
ierr = TSSetMaxTime(ts,30.0);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_STEPOVER);CHKERRQ(ierr);
ierr = TSSetTimeStep(ts,0.1);CHKERRQ(ierr);
/* The adapative time step controller could take very large timesteps resulting in
the same event occuring multiple times in the same interval. A maximum step size
limit is enforced here to avoid this issue. */
ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
ierr = TSAdaptSetStepLimits(adapt,0.0,0.5);CHKERRQ(ierr);
/* Set directions and terminate flags for the two events */
direction[0] = -1; direction[1] = -1;
terminate[0] = PETSC_FALSE; terminate[1] = PETSC_TRUE;
ierr = TSSetEventHandler(ts,2,direction,terminate,EventFunction,PostEventFunction,(void*)&app);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Run timestepping solver
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = TSSolve(ts,U);CHKERRQ(ierr);
if (hist) { /* replay following history */
TSTrajectory tj;
PetscReal tf,t0,dt;
app.nbounces = 0;
ierr = TSGetTime(ts,&tf);CHKERRQ(ierr);
ierr = TSSetMaxTime(ts,tf);CHKERRQ(ierr);
ierr = TSSetStepNumber(ts,0);CHKERRQ(ierr);
ierr = TSRestartStep(ts);CHKERRQ(ierr);
ierr = TSSetExactFinalTime(ts,TS_EXACTFINALTIME_MATCHSTEP);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
ierr = TSGetAdapt(ts,&adapt);CHKERRQ(ierr);
ierr = TSAdaptSetType(adapt,TSADAPTHISTORY);CHKERRQ(ierr);
ierr = TSGetTrajectory(ts,&tj);CHKERRQ(ierr);
ierr = TSAdaptHistorySetTrajectory(adapt,tj,PETSC_FALSE);CHKERRQ(ierr);
ierr = TSAdaptHistoryGetStep(adapt,0,&t0,&dt);CHKERRQ(ierr);
/* this example fails with single (or smaller) precision */
#if defined(PETSC_USE_REAL_SINGLE) || defined(PETSC_USE_REAL__FP16)
ierr = TSAdaptSetType(adapt,TSADAPTBASIC);CHKERRQ(ierr);
ierr = TSAdaptSetStepLimits(adapt,0.0,0.5);CHKERRQ(ierr);
ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
#endif
ierr = TSSetTime(ts,t0);CHKERRQ(ierr);
ierr = TSSetTimeStep(ts,dt);CHKERRQ(ierr);
ierr = TSResetTrajectory(ts);CHKERRQ(ierr);
ierr = VecGetArray(U,&u);CHKERRQ(ierr);
u[0] = 0.0;
u[1] = 20.0;
ierr = VecRestoreArray(U,&u);CHKERRQ(ierr);
ierr = TSSolve(ts,U);CHKERRQ(ierr);
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Free work space. All PETSc objects should be destroyed when they are no longer needed.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
ierr = VecDestroy(&U);CHKERRQ(ierr);
ierr = TSDestroy(&ts);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
