/* Helper rutine to handle user postenvents and recording */ static PetscErrorCode TSPostEvent(TS ts,PetscReal t,Vec U) { PetscErrorCode ierr; TSEvent event = ts->event; PetscBool terminate = PETSC_FALSE; PetscBool restart = PETSC_FALSE; PetscInt i,ctr,stepnum; PetscBool inflag[2],outflag[2]; PetscBool forwardsolve = PETSC_TRUE; /* Flag indicating that TS is doing a forward solve */ PetscFunctionBegin; if (event->postevent) { PetscObjectState state_prev,state_post; ierr = PetscObjectStateGet((PetscObject)U,&state_prev);CHKERRQ(ierr); ierr = (*event->postevent)(ts,event->nevents_zero,event->events_zero,t,U,forwardsolve,event->ctx);CHKERRQ(ierr); ierr = PetscObjectStateGet((PetscObject)U,&state_post);CHKERRQ(ierr); if (state_prev != state_post) restart = PETSC_TRUE; } /* Handle termination events and step restart */ for (i=0; i<event->nevents_zero; i++) if (event->terminate[event->events_zero[i]]) terminate = PETSC_TRUE; inflag[0] = restart; inflag[1] = terminate; ierr = MPIU_Allreduce(inflag,outflag,2,MPIU_BOOL,MPI_LOR,((PetscObject)ts)->comm);CHKERRQ(ierr); restart = outflag[0]; terminate = outflag[1]; if (restart) {ierr = TSRestartStep(ts);CHKERRQ(ierr);} if (terminate) {ierr = TSSetConvergedReason(ts,TS_CONVERGED_EVENT);CHKERRQ(ierr);} event->status = terminate ? TSEVENT_NONE : TSEVENT_RESET_NEXTSTEP; /* Reset event residual functions as states might get changed by the postevent callback */ if (event->postevent) { ierr = VecLockPush(U);CHKERRQ(ierr); ierr = (*event->eventhandler)(ts,t,U,event->fvalue,event->ctx);CHKERRQ(ierr); ierr = VecLockPop(U);CHKERRQ(ierr); } /* Cache current time and event residual functions */ event->ptime_prev = t; for (i=0; i<event->nevents; i++) event->fvalue_prev[i] = event->fvalue[i]; /* Record the event in the event recorder */ ierr = TSGetStepNumber(ts,&stepnum);CHKERRQ(ierr); ctr = event->recorder.ctr; if (ctr == event->recsize) { ierr = TSEventRecorderResize(event);CHKERRQ(ierr); } event->recorder.time[ctr] = t; event->recorder.stepnum[ctr] = stepnum; event->recorder.nevents[ctr] = event->nevents_zero; for (i=0; i<event->nevents_zero; i++) event->recorder.eventidx[ctr][i] = event->events_zero[i]; event->recorder.ctr++; PetscFunctionReturn(0); }
PetscErrorCode PostStep(TS ts) { PetscErrorCode ierr; Vec X,gc; AppCtx *user; PetscScalar sum = 0,asum; PetscReal t,**p; DMDACoor2d **coors; DM cda; PetscInt i,j,xs,ys,xm,ym; PetscFunctionBegin; ierr = TSGetApplicationContext(ts,&user);CHKERRQ(ierr); ierr = TSGetTime(ts,&t);CHKERRQ(ierr); ierr = TSGetSolution(ts,&X);CHKERRQ(ierr); ierr = DMGetCoordinateDM(user->da,&cda);CHKERRQ(ierr); ierr = DMDAGetCorners(cda,&xs,&ys,0,&xm,&ym,0);CHKERRQ(ierr); ierr = DMGetCoordinates(user->da,&gc);CHKERRQ(ierr); ierr = DMDAVecGetArray(cda,gc,&coors);CHKERRQ(ierr); ierr = DMDAVecGetArray(user->da,X,&p);CHKERRQ(ierr); for (i=xs; i < xs+xm; i++) { for (j=ys; j < ys+ym; j++) { // printf("i %d j %d y %g %g\n",i,j,coors[j][i].y,p[j][i]); if (coors[j][i].y < 5) sum += p[j][i]; } } ierr = DMDAVecRestoreArray(cda,gc,&coors);CHKERRQ(ierr); ierr = DMDAVecRestoreArray(user->da,X,&p);CHKERRQ(ierr); ierr = MPI_Allreduce(&sum,&asum,1,MPIU_SCALAR,MPIU_SUM,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"sum(p)*dw*dtheta at t = %f = %f\n",(double)t,(double)(asum));CHKERRQ(ierr); if (sum < 1.0e-2) { ierr = TSSetConvergedReason(ts,TS_CONVERGED_USER);CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"Exiting TS as the integral of PDF is almost zero\n");CHKERRQ(ierr); } PetscFunctionReturn(0); }
PetscErrorCode TSEventHandler(TS ts) { PetscErrorCode ierr; TSEvent event; PetscReal t; Vec U; PetscInt i; PetscReal dt,dt_min; PetscInt rollback=0,in[2],out[2]; PetscInt fvalue_sign,fvalueprev_sign; PetscFunctionBegin; PetscValidHeaderSpecific(ts,TS_CLASSID,1); if (!ts->event) PetscFunctionReturn(0); event = ts->event; ierr = TSGetTime(ts,&t);CHKERRQ(ierr); ierr = TSGetTimeStep(ts,&dt);CHKERRQ(ierr); ierr = TSGetSolution(ts,&U);CHKERRQ(ierr); if (event->status == TSEVENT_NONE) { if (ts->steps == 1) /* After first successful step */ event->timestep_orig = ts->ptime - ts->ptime_prev; event->timestep_prev = dt; } if (event->status == TSEVENT_RESET_NEXTSTEP) { /* Restore time step */ dt = PetscMin(event->timestep_orig,event->timestep_prev); ierr = TSSetTimeStep(ts,dt);CHKERRQ(ierr); event->status = TSEVENT_NONE; } if (event->status == TSEVENT_NONE) { event->ptime_end = t; } ierr = VecLockPush(U);CHKERRQ(ierr); ierr = (*event->eventhandler)(ts,t,U,event->fvalue,event->ctx);CHKERRQ(ierr); ierr = VecLockPop(U);CHKERRQ(ierr); for (i=0; i < event->nevents; i++) { if (PetscAbsScalar(event->fvalue[i]) < event->vtol[i]) { event->status = TSEVENT_ZERO; event->fvalue_right[i] = event->fvalue[i]; continue; } fvalue_sign = PetscSign(PetscRealPart(event->fvalue[i])); fvalueprev_sign = PetscSign(PetscRealPart(event->fvalue_prev[i])); if (fvalueprev_sign != 0 && (fvalue_sign != fvalueprev_sign) && (PetscAbsScalar(event->fvalue_prev[i]) > event->vtol[i])) { switch (event->direction[i]) { case -1: if (fvalue_sign < 0) { rollback = 1; /* Compute new time step */ dt = TSEventComputeStepSize(event->ptime_prev,t,event->ptime_right,event->fvalue_prev[i],event->fvalue[i],event->fvalue_right[i],event->side[i],dt); if (event->monitor) { ierr = PetscViewerASCIIPrintf(event->monitor,"TSEvent: iter %D - Event %D interval detected [%g - %g]\n",event->iterctr,i,(double)event->ptime_prev,(double)t);CHKERRQ(ierr); } event->fvalue_right[i] = event->fvalue[i]; event->side[i] = 1; if (!event->iterctr) event->zerocrossing[i] = PETSC_TRUE; event->status = TSEVENT_LOCATED_INTERVAL; } break; case 1: if (fvalue_sign > 0) { rollback = 1; /* Compute new time step */ dt = TSEventComputeStepSize(event->ptime_prev,t,event->ptime_right,event->fvalue_prev[i],event->fvalue[i],event->fvalue_right[i],event->side[i],dt); if (event->monitor) { ierr = PetscViewerASCIIPrintf(event->monitor,"TSEvent: iter %D - Event %D interval detected [%g - %g]\n",event->iterctr,i,(double)event->ptime_prev,(double)t);CHKERRQ(ierr); } event->fvalue_right[i] = event->fvalue[i]; event->side[i] = 1; if (!event->iterctr) event->zerocrossing[i] = PETSC_TRUE; event->status = TSEVENT_LOCATED_INTERVAL; } break; case 0: rollback = 1; /* Compute new time step */ dt = TSEventComputeStepSize(event->ptime_prev,t,event->ptime_right,event->fvalue_prev[i],event->fvalue[i],event->fvalue_right[i],event->side[i],dt); if (event->monitor) { ierr = PetscViewerASCIIPrintf(event->monitor,"TSEvent: iter %D - Event %D interval detected [%g - %g]\n",event->iterctr,i,(double)event->ptime_prev,(double)t);CHKERRQ(ierr); } event->fvalue_right[i] = event->fvalue[i]; event->side[i] = 1; if (!event->iterctr) event->zerocrossing[i] = PETSC_TRUE; event->status = TSEVENT_LOCATED_INTERVAL; break; } } } in[0] = event->status; in[1] = rollback; ierr = MPIU_Allreduce(in,out,2,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr); event->status = (TSEventStatus)out[0]; rollback = out[1]; if (rollback) event->status = TSEVENT_LOCATED_INTERVAL; event->nevents_zero = 0; if (event->status == TSEVENT_ZERO) { for (i=0; i < event->nevents; i++) { if (PetscAbsScalar(event->fvalue[i]) < event->vtol[i]) { event->events_zero[event->nevents_zero++] = i; if (event->monitor) { ierr = PetscViewerASCIIPrintf(event->monitor,"TSEvent: Event %D zero crossing at time %g located in %D iterations\n",i,(double)t,event->iterctr);CHKERRQ(ierr); } event->zerocrossing[i] = PETSC_FALSE; } event->side[i] = 0; } ierr = TSPostEvent(ts,t,U);CHKERRQ(ierr); dt = event->ptime_end - t; if (PetscAbsReal(dt) < PETSC_SMALL) { /* we hit the event, continue with the candidate time step */ dt = event->timestep_prev; event->status = TSEVENT_NONE; } ierr = TSSetTimeStep(ts,dt);CHKERRQ(ierr); event->iterctr = 0; PetscFunctionReturn(0); } if (event->status == TSEVENT_LOCATED_INTERVAL) { ierr = TSRollBack(ts);CHKERRQ(ierr); ierr = TSSetConvergedReason(ts,TS_CONVERGED_ITERATING);CHKERRQ(ierr); event->status = TSEVENT_PROCESSING; event->ptime_right = t; } else { for (i=0; i < event->nevents; i++) { if (event->status == TSEVENT_PROCESSING && event->zerocrossing[i]) { /* Compute new time step */ dt = TSEventComputeStepSize(event->ptime_prev,t,event->ptime_right,event->fvalue_prev[i],event->fvalue[i],event->fvalue_right[i],event->side[i],dt); event->side[i] = -1; } event->fvalue_prev[i] = event->fvalue[i]; } if (event->monitor && event->status == TSEVENT_PROCESSING) { ierr = PetscViewerASCIIPrintf(event->monitor,"TSEvent: iter %D - Stepping forward as no event detected in interval [%g - %g]\n",event->iterctr,(double)event->ptime_prev,(double)t);CHKERRQ(ierr); } event->ptime_prev = t; } if (event->status == TSEVENT_PROCESSING) event->iterctr++; ierr = MPIU_Allreduce(&dt,&dt_min,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)ts));CHKERRQ(ierr); ierr = TSSetTimeStep(ts,dt_min);CHKERRQ(ierr); PetscFunctionReturn(0); }