1 static char help[] = "Tests TS time span \n\n"; 2 3 #include <petscts.h> 4 5 static PetscErrorCode RHSFunction(TS ts, PetscReal t, Vec X, Vec F, void *ctx) 6 { 7 PetscInt i, n; 8 const PetscScalar *xx; 9 PetscScalar *ff; 10 11 PetscFunctionBeginUser; 12 PetscCall(VecGetLocalSize(X, &n)); 13 PetscCall(VecGetArrayRead(X, &xx)); 14 PetscCall(VecGetArray(F, &ff)); 15 if (n >= 1) ff[0] = 1; 16 for (i = 1; i < n; i++) ff[i] = (i + 1) * (xx[i - 1] + PetscPowReal(t, i)) / 2; 17 PetscCall(VecRestoreArrayRead(X, &xx)); 18 PetscCall(VecRestoreArray(F, &ff)); 19 PetscFunctionReturn(PETSC_SUCCESS); 20 } 21 22 int main(int argc, char *argv[]) 23 { 24 TS ts; 25 Vec X, *Xs; 26 PetscInt i, n, N = 9; 27 PetscReal tspan[8] = {16.0, 16.1, 16.2, 16.3, 16.4, 16.5, 16.6, 16.7}; 28 const PetscReal *tspan2; 29 30 PetscFunctionBeginUser; 31 PetscCall(PetscInitialize(&argc, &argv, NULL, help)); 32 PetscCall(TSCreate(PETSC_COMM_SELF, &ts)); 33 PetscCall(TSSetType(ts, TSRK)); 34 PetscCall(TSSetRHSFunction(ts, NULL, RHSFunction, NULL)); 35 PetscCall(VecCreateSeq(PETSC_COMM_SELF, N, &X)); 36 PetscCall(VecZeroEntries(X)); 37 PetscCall(TSSetTimeStep(ts, 0.001)); 38 PetscCall(TSSetTimeSpan(ts, 8, tspan)); 39 PetscCall(TSSetExactFinalTime(ts, TS_EXACTFINALTIME_MATCHSTEP)); 40 PetscCall(TSSetFromOptions(ts)); 41 PetscCall(TSSolve(ts, X)); 42 PetscCall(TSGetTimeSpanSolutions(ts, &n, &Xs)); 43 PetscCall(TSGetTimeSpan(ts, &n, &tspan2)); 44 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Time Span: ")); 45 for (i = 0; i < n; i++) PetscCall(PetscPrintf(PETSC_COMM_WORLD, " %g", (double)tspan2[i])); 46 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\n")); 47 PetscCall(TSDestroy(&ts)); 48 PetscCall(VecDestroy(&X)); 49 PetscCall(PetscFinalize()); 50 return 0; 51 } 52 53 /*TEST 54 55 testset: 56 test: 57 suffix: 1 58 args: -ts_monitor 59 test: 60 suffix: 2 61 requires: !single 62 args: -ts_monitor -ts_adapt_type none 63 TEST*/ 64