xref: /petsc/src/ts/tutorials/ex48.c (revision d5b43468fb8780a8feea140ccd6fa3e6a50411cc)
1 static char help[] = "Evolution of magnetic islands.\n\
2 The aim of this model is to self-consistently study the interaction between the tearing mode and small scale drift-wave turbulence.\n\n\n";
3 
4 /*F
5 This is a three field model for the density $\tilde n$, vorticity $\tilde\Omega$, and magnetic flux $\tilde\psi$, using auxiliary variables potential $\tilde\phi$ and current $j_z$.
6 \begin{equation}
7   \begin{aligned}
8     \partial_t \tilde n       &= \left\{ \tilde n, \tilde\phi \right\} + \beta \left\{ j_z, \tilde\psi \right\} + \left\{ \ln n_0, \tilde\phi \right\} + \mu \nabla^2_\perp \tilde n \\
9   \partial_t \tilde\Omega   &= \left\{ \tilde\Omega, \tilde\phi \right\} + \beta \left\{ j_z, \tilde\psi \right\} + \mu \nabla^2_\perp \tilde\Omega \\
10   \partial_t \tilde\psi     &= \left\{ \psi_0 + \tilde\psi, \tilde\phi - \tilde n \right\} - \left\{ \ln n_0, \tilde\psi \right\} + \frac{\eta}{\beta} \nabla^2_\perp \tilde\psi \\
11   \nabla^2_\perp\tilde\phi        &= \tilde\Omega \\
12   j_z  &= -\nabla^2_\perp  \left(\tilde\psi + \psi_0  \right)\\
13   \end{aligned}
14 \end{equation}
15 F*/
16 
17 #include <petscdmplex.h>
18 #include <petscts.h>
19 #include <petscds.h>
20 
21 typedef struct {
22   PetscInt  debug;   /* The debugging level */
23   PetscBool plotRef; /* Plot the reference fields */
24   PetscReal lower[3], upper[3];
25   /* Problem definition */
26   PetscErrorCode (**initialFuncs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx);
27   PetscReal mu, eta, beta;
28   PetscReal a, b, Jo, Jop, m, ke, kx, ky, DeltaPrime, eps;
29   /* solver */
30   PetscBool implicit;
31 } AppCtx;
32 
33 static AppCtx *s_ctx;
34 
35 static PetscScalar poissonBracket(PetscInt dim, const PetscScalar df[], const PetscScalar dg[])
36 {
37   PetscScalar ret = df[0] * dg[1] - df[1] * dg[0];
38   return ret;
39 }
40 
41 enum field_idx {
42   DENSITY,
43   OMEGA,
44   PSI,
45   PHI,
46   JZ
47 };
48 
49 static void f0_n(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
50 {
51   const PetscScalar *pnDer        = &u_x[uOff_x[DENSITY]];
52   const PetscScalar *ppsiDer      = &u_x[uOff_x[PSI]];
53   const PetscScalar *pphiDer      = &u_x[uOff_x[PHI]];
54   const PetscScalar *jzDer        = &u_x[uOff_x[JZ]];
55   const PetscScalar *logRefDenDer = &a_x[aOff_x[DENSITY]];
56   f0[0] += -poissonBracket(dim, pnDer, pphiDer) - s_ctx->beta * poissonBracket(dim, jzDer, ppsiDer) - poissonBracket(dim, logRefDenDer, pphiDer);
57   if (u_t) f0[0] += u_t[DENSITY];
58 }
59 
60 static void f1_n(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
61 {
62   const PetscScalar *pnDer = &u_x[uOff_x[DENSITY]];
63   PetscInt           d;
64 
65   for (d = 0; d < dim - 1; ++d) f1[d] = -s_ctx->mu * pnDer[d];
66 }
67 
68 static void f0_Omega(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
69 {
70   const PetscScalar *pOmegaDer = &u_x[uOff_x[OMEGA]];
71   const PetscScalar *ppsiDer   = &u_x[uOff_x[PSI]];
72   const PetscScalar *pphiDer   = &u_x[uOff_x[PHI]];
73   const PetscScalar *jzDer     = &u_x[uOff_x[JZ]];
74 
75   f0[0] += -poissonBracket(dim, pOmegaDer, pphiDer) - s_ctx->beta * poissonBracket(dim, jzDer, ppsiDer);
76   if (u_t) f0[0] += u_t[OMEGA];
77 }
78 
79 static void f1_Omega(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
80 {
81   const PetscScalar *pOmegaDer = &u_x[uOff_x[OMEGA]];
82   PetscInt           d;
83 
84   for (d = 0; d < dim - 1; ++d) f1[d] = -s_ctx->mu * pOmegaDer[d];
85 }
86 
87 static void f0_psi(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
88 {
89   const PetscScalar *pnDer        = &u_x[uOff_x[DENSITY]];
90   const PetscScalar *ppsiDer      = &u_x[uOff_x[PSI]];
91   const PetscScalar *pphiDer      = &u_x[uOff_x[PHI]];
92   const PetscScalar *refPsiDer    = &a_x[aOff_x[PSI]];
93   const PetscScalar *logRefDenDer = &a_x[aOff_x[DENSITY]];
94   PetscScalar        psiDer[3];
95   PetscScalar        phi_n_Der[3];
96   PetscInt           d;
97   if (dim < 2) {
98     MPI_Abort(MPI_COMM_WORLD, 1);
99     return;
100   } /* this is needed so that the clang static analyzer does not generate a warning about variables used by not set */
101   for (d = 0; d < dim; ++d) {
102     psiDer[d]    = refPsiDer[d] + ppsiDer[d];
103     phi_n_Der[d] = pphiDer[d] - pnDer[d];
104   }
105   f0[0] = -poissonBracket(dim, psiDer, phi_n_Der) + poissonBracket(dim, logRefDenDer, ppsiDer);
106   if (u_t) f0[0] += u_t[PSI];
107 }
108 
109 static void f1_psi(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
110 {
111   const PetscScalar *ppsi = &u_x[uOff_x[PSI]];
112   PetscInt           d;
113 
114   for (d = 0; d < dim - 1; ++d) f1[d] = -(s_ctx->eta / s_ctx->beta) * ppsi[d];
115 }
116 
117 static void f0_phi(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
118 {
119   f0[0] = -u[uOff[OMEGA]];
120 }
121 
122 static void f1_phi(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
123 {
124   const PetscScalar *pphi = &u_x[uOff_x[PHI]];
125   PetscInt           d;
126 
127   for (d = 0; d < dim - 1; ++d) f1[d] = pphi[d];
128 }
129 
130 static void f0_jz(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
131 {
132   f0[0] = u[uOff[JZ]];
133 }
134 
135 static void f1_jz(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[])
136 {
137   const PetscScalar *ppsi      = &u_x[uOff_x[PSI]];
138   const PetscScalar *refPsiDer = &a_x[aOff_x[PSI]]; /* aOff_x[PSI] == 2*PSI */
139   PetscInt           d;
140 
141   for (d = 0; d < dim - 1; ++d) f1[d] = ppsi[d] + refPsiDer[d];
142 }
143 
144 static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
145 {
146   PetscFunctionBeginUser;
147   options->debug    = 1;
148   options->plotRef  = PETSC_FALSE;
149   options->implicit = PETSC_FALSE;
150   options->mu       = 0;
151   options->eta      = 0;
152   options->beta     = 1;
153   options->a        = 1;
154   options->b        = PETSC_PI;
155   options->Jop      = 0;
156   options->m        = 1;
157   options->eps      = 1.e-6;
158 
159   PetscOptionsBegin(comm, "", "Poisson Problem Options", "DMPLEX");
160   PetscCall(PetscOptionsInt("-debug", "The debugging level", "ex48.c", options->debug, &options->debug, NULL));
161   PetscCall(PetscOptionsBool("-plot_ref", "Plot the reference fields", "ex48.c", options->plotRef, &options->plotRef, NULL));
162   PetscCall(PetscOptionsReal("-mu", "mu", "ex48.c", options->mu, &options->mu, NULL));
163   PetscCall(PetscOptionsReal("-eta", "eta", "ex48.c", options->eta, &options->eta, NULL));
164   PetscCall(PetscOptionsReal("-beta", "beta", "ex48.c", options->beta, &options->beta, NULL));
165   PetscCall(PetscOptionsReal("-Jop", "Jop", "ex48.c", options->Jop, &options->Jop, NULL));
166   PetscCall(PetscOptionsReal("-m", "m", "ex48.c", options->m, &options->m, NULL));
167   PetscCall(PetscOptionsReal("-eps", "eps", "ex48.c", options->eps, &options->eps, NULL));
168   PetscCall(PetscOptionsBool("-implicit", "Use implicit time integrator", "ex48.c", options->implicit, &options->implicit, NULL));
169   PetscOptionsEnd();
170   options->ke = PetscSqrtScalar(options->Jop);
171   if (options->Jop == 0.0) {
172     options->Jo = 1.0 / PetscPowScalar(options->a, 2);
173   } else {
174     options->Jo = options->Jop * PetscCosReal(options->ke * options->a) / (1.0 - PetscCosReal(options->ke * options->a));
175   }
176   options->ky = PETSC_PI * options->m / options->b;
177   if (PetscPowReal(options->ky, 2) < options->Jop) {
178     options->kx         = PetscSqrtScalar(options->Jop - PetscPowScalar(options->ky, 2));
179     options->DeltaPrime = -2.0 * options->kx * options->a * PetscCosReal(options->kx * options->a) / PetscSinReal(options->kx * options->a);
180   } else if (PetscPowReal(options->ky, 2) > options->Jop) {
181     options->kx         = PetscSqrtScalar(PetscPowScalar(options->ky, 2) - options->Jop);
182     options->DeltaPrime = -2.0 * options->kx * options->a * PetscCoshReal(options->kx * options->a) / PetscSinhReal(options->kx * options->a);
183   } else { /*they're equal (or there's a NaN), lim(x*cot(x))_x->0=1*/
184     options->kx         = 0;
185     options->DeltaPrime = -2.0;
186   }
187   PetscCall(PetscPrintf(comm, "DeltaPrime=%g\n", (double)options->DeltaPrime));
188 
189   PetscFunctionReturn(0);
190 }
191 
192 static void f_n(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar *f0)
193 {
194   const PetscScalar *pn = &u[uOff[DENSITY]];
195   *f0                   = *pn;
196 }
197 
198 static PetscErrorCode PostStep(TS ts)
199 {
200   DM       dm;
201   AppCtx  *ctx;
202   PetscInt stepi, num;
203   Vec      X;
204 
205   PetscFunctionBeginUser;
206   PetscCall(TSGetApplicationContext(ts, &ctx));
207   if (ctx->debug < 1) PetscFunctionReturn(0);
208   PetscCall(TSGetSolution(ts, &X));
209   PetscCall(VecGetDM(X, &dm));
210   PetscCall(TSGetStepNumber(ts, &stepi));
211   PetscCall(DMGetOutputSequenceNumber(dm, &num, NULL));
212   if (num < 0) PetscCall(DMSetOutputSequenceNumber(dm, 0, 0.0));
213   PetscCall(PetscObjectSetName((PetscObject)X, "u"));
214   PetscCall(VecViewFromOptions(X, NULL, "-vec_view"));
215   /* print integrals */
216   {
217     PetscDS     prob;
218     DM          plex;
219     PetscScalar den, tt[5];
220     PetscCall(DMConvert(dm, DMPLEX, &plex));
221     PetscCall(DMGetDS(plex, &prob));
222     PetscCall(PetscDSSetObjective(prob, 0, &f_n));
223     PetscCall(DMPlexComputeIntegralFEM(plex, X, tt, ctx));
224     den = tt[0];
225     PetscCall(DMDestroy(&plex));
226     PetscCall(PetscPrintf(PetscObjectComm((PetscObject)dm), "%" PetscInt_FMT ") total perturbed mass = %g\n", stepi, (double)PetscRealPart(den)));
227   }
228   PetscFunctionReturn(0);
229 }
230 
231 static PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *ctx, DM *dm)
232 {
233   PetscFunctionBeginUser;
234   PetscCall(DMCreate(comm, dm));
235   PetscCall(DMSetType(*dm, DMPLEX));
236   PetscCall(DMSetFromOptions(*dm));
237   PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view"));
238 
239   PetscCall(DMGetBoundingBox(*dm, ctx->lower, ctx->upper));
240   ctx->a = (ctx->upper[0] - ctx->lower[0]) / 2.0;
241   ctx->b = (ctx->upper[1] - ctx->lower[1]) / 2.0;
242   PetscFunctionReturn(0);
243 }
244 
245 static PetscErrorCode log_n_0(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
246 {
247   AppCtx *lctx = (AppCtx *)ctx;
248   u[0]         = 2. * lctx->a + x[0];
249   return 0;
250 }
251 
252 static PetscErrorCode Omega_0(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
253 {
254   u[0] = 0.0;
255   return 0;
256 }
257 
258 static PetscErrorCode psi_0(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
259 {
260   AppCtx *lctx = (AppCtx *)ctx;
261   /* This sets up a symmetrix By flux aroound the mid point in x, which represents a current density flux along z.  The stability
262      is analytically known and reported in ProcessOptions. */
263   if (lctx->ke != 0.0) {
264     u[0] = (PetscCosReal(lctx->ke * (x[0] - lctx->a)) - PetscCosReal(lctx->ke * lctx->a)) / (1.0 - PetscCosReal(lctx->ke * lctx->a));
265   } else {
266     u[0] = 1.0 - PetscPowScalar((x[0] - lctx->a) / lctx->a, 2);
267   }
268   return 0;
269 }
270 
271 static PetscErrorCode initialSolution_n(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
272 {
273   u[0] = 0.0;
274   return 0;
275 }
276 
277 static PetscErrorCode initialSolution_Omega(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
278 {
279   u[0] = 0.0;
280   return 0;
281 }
282 
283 static PetscErrorCode initialSolution_psi(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *a_ctx)
284 {
285   AppCtx     *ctx = (AppCtx *)a_ctx;
286   PetscScalar r   = ctx->eps * (PetscScalar)(rand()) / (PetscScalar)(RAND_MAX);
287   if (x[0] == ctx->lower[0] || x[0] == ctx->upper[0]) r = 0;
288   u[0] = r;
289   /* PetscPrintf(PETSC_COMM_WORLD, "rand psi %lf\n",u[0]); */
290   return 0;
291 }
292 
293 static PetscErrorCode initialSolution_phi(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
294 {
295   u[0] = 0.0;
296   return 0;
297 }
298 
299 static PetscErrorCode initialSolution_jz(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nf, PetscScalar *u, void *ctx)
300 {
301   u[0] = 0.0;
302   return 0;
303 }
304 
305 static PetscErrorCode SetupProblem(DM dm, AppCtx *ctx)
306 {
307   PetscDS        ds;
308   DMLabel        label;
309   const PetscInt id = 1;
310 
311   PetscFunctionBeginUser;
312   PetscCall(DMGetLabel(dm, "marker", &label));
313   PetscCall(DMGetDS(dm, &ds));
314   PetscCall(PetscDSSetResidual(ds, 0, f0_n, f1_n));
315   PetscCall(PetscDSSetResidual(ds, 1, f0_Omega, f1_Omega));
316   PetscCall(PetscDSSetResidual(ds, 2, f0_psi, f1_psi));
317   PetscCall(PetscDSSetResidual(ds, 3, f0_phi, f1_phi));
318   PetscCall(PetscDSSetResidual(ds, 4, f0_jz, f1_jz));
319   ctx->initialFuncs[0] = initialSolution_n;
320   ctx->initialFuncs[1] = initialSolution_Omega;
321   ctx->initialFuncs[2] = initialSolution_psi;
322   ctx->initialFuncs[3] = initialSolution_phi;
323   ctx->initialFuncs[4] = initialSolution_jz;
324   for (PetscInt f = 0; f < 5; ++f) {
325     PetscCall(PetscDSSetImplicit(ds, f, ctx->implicit));
326     PetscCall(DMAddBoundary(dm, DM_BC_ESSENTIAL, "wall", label, 1, &id, f, 0, NULL, (void (*)(void))ctx->initialFuncs[f], NULL, ctx, NULL));
327   }
328   PetscCall(PetscDSSetContext(ds, 0, ctx));
329   PetscFunctionReturn(0);
330 }
331 
332 static PetscErrorCode SetupEquilibriumFields(DM dm, DM dmAux, AppCtx *ctx)
333 {
334   PetscErrorCode (*eqFuncs[3])(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *) = {log_n_0, Omega_0, psi_0};
335   Vec     eq;
336   AppCtx *ctxarr[3];
337 
338   ctxarr[0] = ctxarr[1] = ctxarr[2] = ctx; /* each variable could have a different context */
339   PetscFunctionBeginUser;
340   PetscCall(DMCreateLocalVector(dmAux, &eq));
341   PetscCall(DMProjectFunctionLocal(dmAux, 0.0, eqFuncs, (void **)ctxarr, INSERT_ALL_VALUES, eq));
342   PetscCall(DMSetAuxiliaryVec(dm, NULL, 0, 0, eq));
343   if (ctx->plotRef) { /* plot reference functions */
344     PetscViewer viewer = NULL;
345     PetscBool   isHDF5, isVTK;
346     char        buf[256];
347     Vec         global;
348     PetscInt    dim;
349 
350     PetscCall(DMGetDimension(dm, &dim));
351     PetscCall(DMCreateGlobalVector(dmAux, &global));
352     PetscCall(VecSet(global, .0)); /* BCs! */
353     PetscCall(DMLocalToGlobalBegin(dmAux, eq, INSERT_VALUES, global));
354     PetscCall(DMLocalToGlobalEnd(dmAux, eq, INSERT_VALUES, global));
355     PetscCall(PetscViewerCreate(PetscObjectComm((PetscObject)dmAux), &viewer));
356 #ifdef PETSC_HAVE_HDF5
357     PetscCall(PetscViewerSetType(viewer, PETSCVIEWERHDF5));
358 #else
359     PetscCall(PetscViewerSetType(viewer, PETSCVIEWERVTK));
360 #endif
361     PetscCall(PetscViewerSetFromOptions(viewer));
362     PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &isHDF5));
363     PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERVTK, &isVTK));
364     if (isHDF5) {
365       PetscCall(PetscSNPrintf(buf, 256, "uEquilibrium-%" PetscInt_FMT "D.h5", dim));
366     } else if (isVTK) {
367       PetscCall(PetscSNPrintf(buf, 256, "uEquilibrium-%" PetscInt_FMT "D.vtu", dim));
368       PetscCall(PetscViewerPushFormat(viewer, PETSC_VIEWER_VTK_VTU));
369     }
370     PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_WRITE));
371     PetscCall(PetscViewerFileSetName(viewer, buf));
372     if (isHDF5) PetscCall(DMView(dmAux, viewer));
373     /* view equilibrium fields, this will overwrite fine grids with coarse grids! */
374     PetscCall(PetscObjectSetName((PetscObject)global, "u0"));
375     PetscCall(VecView(global, viewer));
376     PetscCall(PetscViewerDestroy(&viewer));
377     PetscCall(VecDestroy(&global));
378   }
379   PetscCall(VecDestroy(&eq));
380   PetscFunctionReturn(0);
381 }
382 
383 static PetscErrorCode SetupAuxDM(DM dm, PetscInt NfAux, PetscFE feAux[], AppCtx *user)
384 {
385   DM       dmAux, coordDM;
386   PetscInt f;
387 
388   PetscFunctionBeginUser;
389   /* MUST call DMGetCoordinateDM() in order to get p4est setup if present */
390   PetscCall(DMGetCoordinateDM(dm, &coordDM));
391   if (!feAux) PetscFunctionReturn(0);
392   PetscCall(DMClone(dm, &dmAux));
393   PetscCall(DMSetCoordinateDM(dmAux, coordDM));
394   for (f = 0; f < NfAux; ++f) PetscCall(DMSetField(dmAux, f, NULL, (PetscObject)feAux[f]));
395   PetscCall(DMCreateDS(dmAux));
396   PetscCall(SetupEquilibriumFields(dm, dmAux, user));
397   PetscCall(DMDestroy(&dmAux));
398   PetscFunctionReturn(0);
399 }
400 
401 static PetscErrorCode SetupDiscretization(DM dm, AppCtx *ctx)
402 {
403   DM        cdm = dm;
404   PetscFE   fe[5], feAux[3];
405   PetscInt  dim, Nf = 5, NfAux = 3, f;
406   PetscBool simplex;
407   MPI_Comm  comm;
408 
409   PetscFunctionBeginUser;
410   /* Create finite element */
411   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
412   PetscCall(DMGetDimension(dm, &dim));
413   PetscCall(DMPlexIsSimplex(dm, &simplex));
414   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &fe[0]));
415   PetscCall(PetscObjectSetName((PetscObject)fe[0], "density"));
416   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &fe[1]));
417   PetscCall(PetscObjectSetName((PetscObject)fe[1], "vorticity"));
418   PetscCall(PetscFECopyQuadrature(fe[0], fe[1]));
419   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &fe[2]));
420   PetscCall(PetscObjectSetName((PetscObject)fe[2], "flux"));
421   PetscCall(PetscFECopyQuadrature(fe[0], fe[2]));
422   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &fe[3]));
423   PetscCall(PetscObjectSetName((PetscObject)fe[3], "potential"));
424   PetscCall(PetscFECopyQuadrature(fe[0], fe[3]));
425   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &fe[4]));
426   PetscCall(PetscObjectSetName((PetscObject)fe[4], "current"));
427   PetscCall(PetscFECopyQuadrature(fe[0], fe[4]));
428 
429   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &feAux[0]));
430   PetscCall(PetscObjectSetName((PetscObject)feAux[0], "n_0"));
431   PetscCall(PetscFECopyQuadrature(fe[0], feAux[0]));
432   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &feAux[1]));
433   PetscCall(PetscObjectSetName((PetscObject)feAux[1], "vorticity_0"));
434   PetscCall(PetscFECopyQuadrature(fe[0], feAux[1]));
435   PetscCall(PetscFECreateDefault(comm, dim, 1, simplex, NULL, -1, &feAux[2]));
436   PetscCall(PetscObjectSetName((PetscObject)feAux[2], "flux_0"));
437   PetscCall(PetscFECopyQuadrature(fe[0], feAux[2]));
438   /* Set discretization and boundary conditions for each mesh */
439   for (f = 0; f < Nf; ++f) PetscCall(DMSetField(dm, f, NULL, (PetscObject)fe[f]));
440   PetscCall(DMCreateDS(dm));
441   PetscCall(SetupProblem(dm, ctx));
442   while (cdm) {
443     PetscCall(SetupAuxDM(dm, NfAux, feAux, ctx));
444     PetscCall(DMCopyDisc(dm, cdm));
445     PetscCall(DMGetCoarseDM(cdm, &cdm));
446   }
447   for (f = 0; f < Nf; ++f) PetscCall(PetscFEDestroy(&fe[f]));
448   for (f = 0; f < NfAux; ++f) PetscCall(PetscFEDestroy(&feAux[f]));
449   PetscFunctionReturn(0);
450 }
451 
452 int main(int argc, char **argv)
453 {
454   DM        dm;
455   TS        ts;
456   Vec       u, r;
457   AppCtx    ctx;
458   PetscReal t       = 0.0;
459   PetscReal L2error = 0.0;
460   AppCtx   *ctxarr[5];
461 
462   ctxarr[0] = ctxarr[1] = ctxarr[2] = ctxarr[3] = ctxarr[4] = &ctx; /* each variable could have a different context */
463   s_ctx                                                     = &ctx;
464   PetscFunctionBeginUser;
465   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
466   PetscCall(ProcessOptions(PETSC_COMM_WORLD, &ctx));
467   /* create mesh and problem */
468   PetscCall(CreateMesh(PETSC_COMM_WORLD, &ctx, &dm));
469   PetscCall(DMSetApplicationContext(dm, &ctx));
470   PetscCall(PetscMalloc1(5, &ctx.initialFuncs));
471   PetscCall(SetupDiscretization(dm, &ctx));
472   PetscCall(DMCreateGlobalVector(dm, &u));
473   PetscCall(PetscObjectSetName((PetscObject)u, "u"));
474   PetscCall(VecDuplicate(u, &r));
475   PetscCall(PetscObjectSetName((PetscObject)r, "r"));
476   /* create TS */
477   PetscCall(TSCreate(PETSC_COMM_WORLD, &ts));
478   PetscCall(TSSetDM(ts, dm));
479   PetscCall(TSSetApplicationContext(ts, &ctx));
480   PetscCall(DMTSSetBoundaryLocal(dm, DMPlexTSComputeBoundary, &ctx));
481   if (ctx.implicit) {
482     PetscCall(DMTSSetIFunctionLocal(dm, DMPlexTSComputeIFunctionFEM, &ctx));
483     PetscCall(DMTSSetIJacobianLocal(dm, DMPlexTSComputeIJacobianFEM, &ctx));
484   } else {
485     PetscCall(DMTSSetRHSFunctionLocal(dm, DMPlexTSComputeRHSFunctionFVM, &ctx));
486   }
487   PetscCall(TSSetExactFinalTime(ts, TS_EXACTFINALTIME_STEPOVER));
488   PetscCall(TSSetFromOptions(ts));
489   PetscCall(TSSetPostStep(ts, PostStep));
490   /* make solution & solve */
491   PetscCall(DMProjectFunction(dm, t, ctx.initialFuncs, (void **)ctxarr, INSERT_ALL_VALUES, u));
492   PetscCall(TSSetSolution(ts, u));
493   PetscCall(DMViewFromOptions(dm, NULL, "-dm_view"));
494   PetscCall(PostStep(ts)); /* print the initial state */
495   PetscCall(TSSolve(ts, u));
496   PetscCall(TSGetTime(ts, &t));
497   PetscCall(DMComputeL2Diff(dm, t, ctx.initialFuncs, (void **)ctxarr, u, &L2error));
498   if (L2error < 1.0e-11) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "L_2 Error: < 1.0e-11\n"));
499   else PetscCall(PetscPrintf(PETSC_COMM_WORLD, "L_2 Error: %g\n", (double)L2error));
500   PetscCall(VecDestroy(&u));
501   PetscCall(VecDestroy(&r));
502   PetscCall(TSDestroy(&ts));
503   PetscCall(DMDestroy(&dm));
504   PetscCall(PetscFree(ctx.initialFuncs));
505   PetscCall(PetscFinalize());
506   return 0;
507 }
508 
509 /*TEST
510 
511   test:
512     suffix: 0
513     args: -debug 1 -dm_refine 1 -dm_plex_simplex 0 -dm_plex_box_faces 3,3 -dm_plex_box_bd periodic,none -dm_plex_box_upper 2.0,6.283185307179586 \
514           -ts_max_steps 1 -ts_max_time 10. -ts_dt 1.0
515   test:
516     # Remapping with periodicity is broken
517     suffix: 1
518     args: -debug 1 -dm_plex_shape cylinder -dm_plex_dim 3 -dm_refine 1 -dm_refine_remap 0 -dm_plex_cylinder_bd periodic -dm_plex_boundary_label marker \
519            -ts_max_steps 1 -ts_max_time 10. -ts_dt 1.0
520 
521 TEST*/
522