xref: /petsc/src/ts/tutorials/power_grid/ex6.c (revision df4cd43f92eaa320656440c40edb1046daee8f75)
1 static char help[] = "Time-dependent PDE in 2d for calculating joint PDF. \n";
2 /*
3    p_t = -x_t*p_x -y_t*p_y + f(t)*p_yy
4    xmin < x < xmax, ymin < y < ymax;
5    x_t = (y - ws)  y_t = (ws/2H)*(Pm - Pmax*sin(x))
6 
7    Boundary conditions: -bc_type 0 => Zero dirichlet boundary
8                         -bc_type 1 => Steady state boundary condition
9    Steady state boundary condition found by setting p_t = 0
10 */
11 
12 #include <petscdm.h>
13 #include <petscdmda.h>
14 #include <petscts.h>
15 
16 /*
17    User-defined data structures and routines
18 */
19 typedef struct {
20   PetscScalar ws;         /* Synchronous speed */
21   PetscScalar H;          /* Inertia constant */
22   PetscScalar D;          /* Damping constant */
23   PetscScalar Pmax;       /* Maximum power output of generator */
24   PetscScalar PM_min;     /* Mean mechanical power input */
25   PetscScalar lambda;     /* correlation time */
26   PetscScalar q;          /* noise strength */
27   PetscScalar mux;        /* Initial average angle */
28   PetscScalar sigmax;     /* Standard deviation of initial angle */
29   PetscScalar muy;        /* Average speed */
30   PetscScalar sigmay;     /* standard deviation of initial speed */
31   PetscScalar rho;        /* Cross-correlation coefficient */
32   PetscScalar t0;         /* Initial time */
33   PetscScalar tmax;       /* Final time */
34   PetscScalar xmin;       /* left boundary of angle */
35   PetscScalar xmax;       /* right boundary of angle */
36   PetscScalar ymin;       /* bottom boundary of speed */
37   PetscScalar ymax;       /* top boundary of speed */
38   PetscScalar dx;         /* x step size */
39   PetscScalar dy;         /* y step size */
40   PetscInt    bc;         /* Boundary conditions */
41   PetscScalar disper_coe; /* Dispersion coefficient */
42   DM          da;
43 } AppCtx;
44 
45 PetscErrorCode Parameter_settings(AppCtx *);
46 PetscErrorCode ini_bou(Vec, AppCtx *);
47 PetscErrorCode IFunction(TS, PetscReal, Vec, Vec, Vec, void *);
48 PetscErrorCode IJacobian(TS, PetscReal, Vec, Vec, PetscReal, Mat, Mat, void *);
49 PetscErrorCode PostStep(TS);
50 
51 int main(int argc, char **argv)
52 {
53   Vec         x;    /* Solution vector */
54   TS          ts;   /* Time-stepping context */
55   AppCtx      user; /* Application context */
56   Mat         J;
57   PetscViewer viewer;
58 
59   PetscFunctionBeginUser;
60   PetscCall(PetscInitialize(&argc, &argv, "petscopt_ex6", help));
61   /* Get physics and time parameters */
62   PetscCall(Parameter_settings(&user));
63   /* Create a 2D DA with dof = 1 */
64   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_STAR, 4, 4, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &user.da));
65   PetscCall(DMSetFromOptions(user.da));
66   PetscCall(DMSetUp(user.da));
67   /* Set x and y coordinates */
68   PetscCall(DMDASetUniformCoordinates(user.da, user.xmin, user.xmax, user.ymin, user.ymax, 0.0, 1.0));
69 
70   /* Get global vector x from DM  */
71   PetscCall(DMCreateGlobalVector(user.da, &x));
72 
73   PetscCall(ini_bou(x, &user));
74   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "ini_x", FILE_MODE_WRITE, &viewer));
75   PetscCall(VecView(x, viewer));
76   PetscCall(PetscViewerDestroy(&viewer));
77 
78   /* Get Jacobian matrix structure from the da */
79   PetscCall(DMSetMatType(user.da, MATAIJ));
80   PetscCall(DMCreateMatrix(user.da, &J));
81 
82   PetscCall(TSCreate(PETSC_COMM_WORLD, &ts));
83   PetscCall(TSSetProblemType(ts, TS_NONLINEAR));
84   PetscCall(TSSetIFunction(ts, NULL, IFunction, &user));
85   PetscCall(TSSetIJacobian(ts, J, J, IJacobian, &user));
86   PetscCall(TSSetApplicationContext(ts, &user));
87   PetscCall(TSSetMaxTime(ts, user.tmax));
88   PetscCall(TSSetExactFinalTime(ts, TS_EXACTFINALTIME_MATCHSTEP));
89   PetscCall(TSSetTime(ts, user.t0));
90   PetscCall(TSSetTimeStep(ts, .005));
91   PetscCall(TSSetFromOptions(ts));
92   PetscCall(TSSetPostStep(ts, PostStep));
93   PetscCall(TSSolve(ts, x));
94 
95   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "fin_x", FILE_MODE_WRITE, &viewer));
96   PetscCall(VecView(x, viewer));
97   PetscCall(PetscViewerDestroy(&viewer));
98 
99   PetscCall(VecDestroy(&x));
100   PetscCall(MatDestroy(&J));
101   PetscCall(DMDestroy(&user.da));
102   PetscCall(TSDestroy(&ts));
103   PetscCall(PetscFinalize());
104   return 0;
105 }
106 
107 PetscErrorCode PostStep(TS ts)
108 {
109   Vec         X;
110   AppCtx     *user;
111   PetscScalar sum;
112   PetscReal   t;
113 
114   PetscFunctionBegin;
115   PetscCall(TSGetApplicationContext(ts, &user));
116   PetscCall(TSGetTime(ts, &t));
117   PetscCall(TSGetSolution(ts, &X));
118   PetscCall(VecSum(X, &sum));
119   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "sum(p)*dw*dtheta at t = %3.2f = %3.6f\n", (double)t, (double)(sum * user->dx * user->dy)));
120   PetscFunctionReturn(PETSC_SUCCESS);
121 }
122 
123 PetscErrorCode ini_bou(Vec X, AppCtx *user)
124 {
125   DM            cda;
126   DMDACoor2d  **coors;
127   PetscScalar **p;
128   Vec           gc;
129   PetscInt      i, j;
130   PetscInt      xs, ys, xm, ym, M, N;
131   PetscScalar   xi, yi;
132   PetscScalar   sigmax = user->sigmax, sigmay = user->sigmay;
133   PetscScalar   rho = user->rho;
134   PetscScalar   mux = user->mux, muy = user->muy;
135   PetscMPIInt   rank;
136 
137   PetscFunctionBeginUser;
138   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
139   PetscCall(DMDAGetInfo(user->da, NULL, &M, &N, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL));
140   user->dx = (user->xmax - user->xmin) / (M - 1);
141   user->dy = (user->ymax - user->ymin) / (N - 1);
142   PetscCall(DMGetCoordinateDM(user->da, &cda));
143   PetscCall(DMGetCoordinates(user->da, &gc));
144   PetscCall(DMDAVecGetArray(cda, gc, &coors));
145   PetscCall(DMDAVecGetArray(user->da, X, &p));
146   PetscCall(DMDAGetCorners(cda, &xs, &ys, 0, &xm, &ym, 0));
147   for (i = xs; i < xs + xm; i++) {
148     for (j = ys; j < ys + ym; j++) {
149       xi = coors[j][i].x;
150       yi = coors[j][i].y;
151       if (i == 0 || j == 0 || i == M - 1 || j == N - 1) p[j][i] = 0.0;
152       else
153         p[j][i] = (0.5 / (PETSC_PI * sigmax * sigmay * PetscSqrtScalar(1.0 - rho * rho))) * PetscExpScalar(-0.5 / (1 - rho * rho) * (PetscPowScalar((xi - mux) / sigmax, 2) + PetscPowScalar((yi - muy) / sigmay, 2) - 2 * rho * (xi - mux) * (yi - muy) / (sigmax * sigmay)));
154     }
155   }
156   /*  p[N/2+N%2][M/2+M%2] = 1/(user->dx*user->dy); */
157 
158   PetscCall(DMDAVecRestoreArray(cda, gc, &coors));
159   PetscCall(DMDAVecRestoreArray(user->da, X, &p));
160   PetscFunctionReturn(PETSC_SUCCESS);
161 }
162 
163 /* First advection term */
164 PetscErrorCode adv1(PetscScalar **p, PetscScalar y, PetscInt i, PetscInt j, PetscInt M, PetscScalar *p1, AppCtx *user)
165 {
166   PetscScalar f;
167   /*  PetscScalar v1,v2,v3,v4,v5,s1,s2,s3; */
168   PetscFunctionBegin;
169   /*  if (i > 2 && i < M-2) {
170     v1 = (y-user->ws)*(p[j][i-2] - p[j][i-3])/user->dx;
171     v2 = (y-user->ws)*(p[j][i-1] - p[j][i-2])/user->dx;
172     v3 = (y-user->ws)*(p[j][i] - p[j][i-1])/user->dx;
173     v4 = (y-user->ws)*(p[j][i+1] - p[j][i])/user->dx;
174     v5 = (y-user->ws)*(p[j][i+1] - p[j][i+2])/user->dx;
175 
176     s1 = v1/3.0 - (7.0/6.0)*v2 + (11.0/6.0)*v3;
177     s2 =-v2/6.0 + (5.0/6.0)*v3 + (1.0/3.0)*v4;
178     s3 = v3/3.0 + (5.0/6.0)*v4 - (1.0/6.0)*v5;
179 
180     *p1 = 0.1*s1 + 0.6*s2 + 0.3*s3;
181     } else *p1 = 0.0; */
182   f   = (y - user->ws);
183   *p1 = f * (p[j][i + 1] - p[j][i - 1]) / (2 * user->dx);
184   PetscFunctionReturn(PETSC_SUCCESS);
185 }
186 
187 /* Second advection term */
188 PetscErrorCode adv2(PetscScalar **p, PetscScalar x, PetscInt i, PetscInt j, PetscInt N, PetscScalar *p2, AppCtx *user)
189 {
190   PetscScalar f;
191   /*  PetscScalar v1,v2,v3,v4,v5,s1,s2,s3; */
192   PetscFunctionBegin;
193   /*  if (j > 2 && j < N-2) {
194     v1 = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*sin(x))*(p[j-2][i] - p[j-3][i])/user->dy;
195     v2 = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*sin(x))*(p[j-1][i] - p[j-2][i])/user->dy;
196     v3 = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*sin(x))*(p[j][i] - p[j-1][i])/user->dy;
197     v4 = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*sin(x))*(p[j+1][i] - p[j][i])/user->dy;
198     v5 = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*sin(x))*(p[j+2][i] - p[j+1][i])/user->dy;
199 
200     s1 = v1/3.0 - (7.0/6.0)*v2 + (11.0/6.0)*v3;
201     s2 =-v2/6.0 + (5.0/6.0)*v3 + (1.0/3.0)*v4;
202     s3 = v3/3.0 + (5.0/6.0)*v4 - (1.0/6.0)*v5;
203 
204     *p2 = 0.1*s1 + 0.6*s2 + 0.3*s3;
205     } else *p2 = 0.0; */
206   f   = (user->ws / (2 * user->H)) * (user->PM_min - user->Pmax * PetscSinScalar(x));
207   *p2 = f * (p[j + 1][i] - p[j - 1][i]) / (2 * user->dy);
208   PetscFunctionReturn(PETSC_SUCCESS);
209 }
210 
211 /* Diffusion term */
212 PetscErrorCode diffuse(PetscScalar **p, PetscInt i, PetscInt j, PetscReal t, PetscScalar *p_diff, AppCtx *user)
213 {
214   PetscFunctionBeginUser;
215 
216   *p_diff = user->disper_coe * ((p[j - 1][i] - 2 * p[j][i] + p[j + 1][i]) / (user->dy * user->dy));
217   PetscFunctionReturn(PETSC_SUCCESS);
218 }
219 
220 PetscErrorCode BoundaryConditions(PetscScalar **p, DMDACoor2d **coors, PetscInt i, PetscInt j, PetscInt M, PetscInt N, PetscScalar **f, AppCtx *user)
221 {
222   PetscScalar fwc, fthetac;
223   PetscScalar w = coors[j][i].y, theta = coors[j][i].x;
224 
225   PetscFunctionBeginUser;
226   if (user->bc == 0) { /* Natural boundary condition */
227     f[j][i] = p[j][i];
228   } else { /* Steady state boundary condition */
229     fthetac = user->ws / (2 * user->H) * (user->PM_min - user->Pmax * PetscSinScalar(theta));
230     fwc     = (w * w / 2.0 - user->ws * w);
231     if (i == 0 && j == 0) { /* left bottom corner */
232       f[j][i] = fwc * (p[j][i + 1] - p[j][i]) / user->dx + fthetac * p[j][i] - user->disper_coe * (p[j + 1][i] - p[j][i]) / user->dy;
233     } else if (i == 0 && j == N - 1) { /* right bottom corner */
234       f[j][i] = fwc * (p[j][i + 1] - p[j][i]) / user->dx + fthetac * p[j][i] - user->disper_coe * (p[j][i] - p[j - 1][i]) / user->dy;
235     } else if (i == M - 1 && j == 0) { /* left top corner */
236       f[j][i] = fwc * (p[j][i] - p[j][i - 1]) / user->dx + fthetac * p[j][i] - user->disper_coe * (p[j + 1][i] - p[j][i]) / user->dy;
237     } else if (i == M - 1 && j == N - 1) { /* right top corner */
238       f[j][i] = fwc * (p[j][i] - p[j][i - 1]) / user->dx + fthetac * p[j][i] - user->disper_coe * (p[j][i] - p[j - 1][i]) / user->dy;
239     } else if (i == 0) { /* Bottom edge */
240       f[j][i] = fwc * (p[j][i + 1] - p[j][i]) / (user->dx) + fthetac * p[j][i] - user->disper_coe * (p[j + 1][i] - p[j - 1][i]) / (2 * user->dy);
241     } else if (i == M - 1) { /* Top edge */
242       f[j][i] = fwc * (p[j][i] - p[j][i - 1]) / (user->dx) + fthetac * p[j][i] - user->disper_coe * (p[j + 1][i] - p[j - 1][i]) / (2 * user->dy);
243     } else if (j == 0) { /* Left edge */
244       f[j][i] = fwc * (p[j][i + 1] - p[j][i - 1]) / (2 * user->dx) + fthetac * p[j][i] - user->disper_coe * (p[j + 1][i] - p[j][i]) / (user->dy);
245     } else if (j == N - 1) { /* Right edge */
246       f[j][i] = fwc * (p[j][i + 1] - p[j][i - 1]) / (2 * user->dx) + fthetac * p[j][i] - user->disper_coe * (p[j][i] - p[j - 1][i]) / (user->dy);
247     }
248   }
249   PetscFunctionReturn(PETSC_SUCCESS);
250 }
251 
252 PetscErrorCode IFunction(TS ts, PetscReal t, Vec X, Vec Xdot, Vec F, void *ctx)
253 {
254   AppCtx       *user = (AppCtx *)ctx;
255   DM            cda;
256   DMDACoor2d  **coors;
257   PetscScalar **p, **f, **pdot;
258   PetscInt      i, j;
259   PetscInt      xs, ys, xm, ym, M, N;
260   Vec           localX, gc, localXdot;
261   PetscScalar   p_adv1, p_adv2, p_diff;
262 
263   PetscFunctionBeginUser;
264   PetscCall(DMDAGetInfo(user->da, NULL, &M, &N, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL));
265   PetscCall(DMGetCoordinateDM(user->da, &cda));
266   PetscCall(DMDAGetCorners(cda, &xs, &ys, 0, &xm, &ym, 0));
267 
268   PetscCall(DMGetLocalVector(user->da, &localX));
269   PetscCall(DMGetLocalVector(user->da, &localXdot));
270 
271   PetscCall(DMGlobalToLocalBegin(user->da, X, INSERT_VALUES, localX));
272   PetscCall(DMGlobalToLocalEnd(user->da, X, INSERT_VALUES, localX));
273   PetscCall(DMGlobalToLocalBegin(user->da, Xdot, INSERT_VALUES, localXdot));
274   PetscCall(DMGlobalToLocalEnd(user->da, Xdot, INSERT_VALUES, localXdot));
275 
276   PetscCall(DMGetCoordinatesLocal(user->da, &gc));
277 
278   PetscCall(DMDAVecGetArrayRead(cda, gc, &coors));
279   PetscCall(DMDAVecGetArrayRead(user->da, localX, &p));
280   PetscCall(DMDAVecGetArrayRead(user->da, localXdot, &pdot));
281   PetscCall(DMDAVecGetArray(user->da, F, &f));
282 
283   user->disper_coe = PetscPowScalar((user->lambda * user->ws) / (2 * user->H), 2) * user->q * (1.0 - PetscExpScalar(-t / user->lambda));
284   for (i = xs; i < xs + xm; i++) {
285     for (j = ys; j < ys + ym; j++) {
286       if (i == 0 || j == 0 || i == M - 1 || j == N - 1) {
287         PetscCall(BoundaryConditions(p, coors, i, j, M, N, f, user));
288       } else {
289         PetscCall(adv1(p, coors[j][i].y, i, j, M, &p_adv1, user));
290         PetscCall(adv2(p, coors[j][i].x, i, j, N, &p_adv2, user));
291         PetscCall(diffuse(p, i, j, t, &p_diff, user));
292         f[j][i] = -p_adv1 - p_adv2 + p_diff - pdot[j][i];
293       }
294     }
295   }
296   PetscCall(DMDAVecRestoreArrayRead(user->da, localX, &p));
297   PetscCall(DMDAVecRestoreArrayRead(user->da, localX, &pdot));
298   PetscCall(DMRestoreLocalVector(user->da, &localX));
299   PetscCall(DMRestoreLocalVector(user->da, &localXdot));
300   PetscCall(DMDAVecRestoreArray(user->da, F, &f));
301   PetscCall(DMDAVecRestoreArrayRead(cda, gc, &coors));
302 
303   PetscFunctionReturn(PETSC_SUCCESS);
304 }
305 
306 PetscErrorCode IJacobian(TS ts, PetscReal t, Vec X, Vec Xdot, PetscReal a, Mat J, Mat Jpre, void *ctx)
307 {
308   AppCtx      *user = (AppCtx *)ctx;
309   DM           cda;
310   DMDACoor2d **coors;
311   PetscInt     i, j;
312   PetscInt     xs, ys, xm, ym, M, N;
313   Vec          gc;
314   PetscScalar  val[5], xi, yi;
315   MatStencil   row, col[5];
316   PetscScalar  c1, c3, c5;
317 
318   PetscFunctionBeginUser;
319   PetscCall(DMDAGetInfo(user->da, NULL, &M, &N, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL));
320   PetscCall(DMGetCoordinateDM(user->da, &cda));
321   PetscCall(DMDAGetCorners(cda, &xs, &ys, 0, &xm, &ym, 0));
322 
323   PetscCall(DMGetCoordinatesLocal(user->da, &gc));
324   PetscCall(DMDAVecGetArrayRead(cda, gc, &coors));
325   for (i = xs; i < xs + xm; i++) {
326     for (j = ys; j < ys + ym; j++) {
327       PetscInt nc = 0;
328       xi          = coors[j][i].x;
329       yi          = coors[j][i].y;
330       row.i       = i;
331       row.j       = j;
332       if (i == 0 || j == 0 || i == M - 1 || j == N - 1) {
333         if (user->bc == 0) {
334           col[nc].i = i;
335           col[nc].j = j;
336           val[nc++] = 1.0;
337         } else {
338           PetscScalar fthetac, fwc;
339           fthetac = user->ws / (2 * user->H) * (user->PM_min - user->Pmax * PetscSinScalar(xi));
340           fwc     = (yi * yi / 2.0 - user->ws * yi);
341           if (i == 0 && j == 0) {
342             col[nc].i = i + 1;
343             col[nc].j = j;
344             val[nc++] = fwc / user->dx;
345             col[nc].i = i;
346             col[nc].j = j + 1;
347             val[nc++] = -user->disper_coe / user->dy;
348             col[nc].i = i;
349             col[nc].j = j;
350             val[nc++] = -fwc / user->dx + fthetac + user->disper_coe / user->dy;
351           } else if (i == 0 && j == N - 1) {
352             col[nc].i = i + 1;
353             col[nc].j = j;
354             val[nc++] = fwc / user->dx;
355             col[nc].i = i;
356             col[nc].j = j - 1;
357             val[nc++] = user->disper_coe / user->dy;
358             col[nc].i = i;
359             col[nc].j = j;
360             val[nc++] = -fwc / user->dx + fthetac - user->disper_coe / user->dy;
361           } else if (i == M - 1 && j == 0) {
362             col[nc].i = i - 1;
363             col[nc].j = j;
364             val[nc++] = -fwc / user->dx;
365             col[nc].i = i;
366             col[nc].j = j + 1;
367             val[nc++] = -user->disper_coe / user->dy;
368             col[nc].i = i;
369             col[nc].j = j;
370             val[nc++] = fwc / user->dx + fthetac + user->disper_coe / user->dy;
371           } else if (i == M - 1 && j == N - 1) {
372             col[nc].i = i - 1;
373             col[nc].j = j;
374             val[nc++] = -fwc / user->dx;
375             col[nc].i = i;
376             col[nc].j = j - 1;
377             val[nc++] = user->disper_coe / user->dy;
378             col[nc].i = i;
379             col[nc].j = j;
380             val[nc++] = fwc / user->dx + fthetac - user->disper_coe / user->dy;
381           } else if (i == 0) {
382             col[nc].i = i + 1;
383             col[nc].j = j;
384             val[nc++] = fwc / user->dx;
385             col[nc].i = i;
386             col[nc].j = j + 1;
387             val[nc++] = -user->disper_coe / (2 * user->dy);
388             col[nc].i = i;
389             col[nc].j = j - 1;
390             val[nc++] = user->disper_coe / (2 * user->dy);
391             col[nc].i = i;
392             col[nc].j = j;
393             val[nc++] = -fwc / user->dx + fthetac;
394           } else if (i == M - 1) {
395             col[nc].i = i - 1;
396             col[nc].j = j;
397             val[nc++] = -fwc / user->dx;
398             col[nc].i = i;
399             col[nc].j = j + 1;
400             val[nc++] = -user->disper_coe / (2 * user->dy);
401             col[nc].i = i;
402             col[nc].j = j - 1;
403             val[nc++] = user->disper_coe / (2 * user->dy);
404             col[nc].i = i;
405             col[nc].j = j;
406             val[nc++] = fwc / user->dx + fthetac;
407           } else if (j == 0) {
408             col[nc].i = i + 1;
409             col[nc].j = j;
410             val[nc++] = fwc / (2 * user->dx);
411             col[nc].i = i - 1;
412             col[nc].j = j;
413             val[nc++] = -fwc / (2 * user->dx);
414             col[nc].i = i;
415             col[nc].j = j + 1;
416             val[nc++] = -user->disper_coe / user->dy;
417             col[nc].i = i;
418             col[nc].j = j;
419             val[nc++] = user->disper_coe / user->dy + fthetac;
420           } else if (j == N - 1) {
421             col[nc].i = i + 1;
422             col[nc].j = j;
423             val[nc++] = fwc / (2 * user->dx);
424             col[nc].i = i - 1;
425             col[nc].j = j;
426             val[nc++] = -fwc / (2 * user->dx);
427             col[nc].i = i;
428             col[nc].j = j - 1;
429             val[nc++] = user->disper_coe / user->dy;
430             col[nc].i = i;
431             col[nc].j = j;
432             val[nc++] = -user->disper_coe / user->dy + fthetac;
433           }
434         }
435       } else {
436         c1        = (yi - user->ws) / (2 * user->dx);
437         c3        = (user->ws / (2.0 * user->H)) * (user->PM_min - user->Pmax * PetscSinScalar(xi)) / (2 * user->dy);
438         c5        = (PetscPowScalar((user->lambda * user->ws) / (2 * user->H), 2) * user->q * (1.0 - PetscExpScalar(-t / user->lambda))) / (user->dy * user->dy);
439         col[nc].i = i - 1;
440         col[nc].j = j;
441         val[nc++] = c1;
442         col[nc].i = i + 1;
443         col[nc].j = j;
444         val[nc++] = -c1;
445         col[nc].i = i;
446         col[nc].j = j - 1;
447         val[nc++] = c3 + c5;
448         col[nc].i = i;
449         col[nc].j = j + 1;
450         val[nc++] = -c3 + c5;
451         col[nc].i = i;
452         col[nc].j = j;
453         val[nc++] = -2 * c5 - a;
454       }
455       PetscCall(MatSetValuesStencil(Jpre, 1, &row, nc, col, val, INSERT_VALUES));
456     }
457   }
458   PetscCall(DMDAVecRestoreArrayRead(cda, gc, &coors));
459 
460   PetscCall(MatAssemblyBegin(Jpre, MAT_FINAL_ASSEMBLY));
461   PetscCall(MatAssemblyEnd(Jpre, MAT_FINAL_ASSEMBLY));
462   if (J != Jpre) {
463     PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
464     PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
465   }
466   PetscFunctionReturn(PETSC_SUCCESS);
467 }
468 
469 PetscErrorCode Parameter_settings(AppCtx *user)
470 {
471   PetscBool flg;
472 
473   PetscFunctionBeginUser;
474 
475   /* Set default parameters */
476   user->ws     = 1.0;
477   user->H      = 5.0;
478   user->Pmax   = 2.1;
479   user->PM_min = 1.0;
480   user->lambda = 0.1;
481   user->q      = 1.0;
482   user->mux    = PetscAsinScalar(user->PM_min / user->Pmax);
483   user->sigmax = 0.1;
484   user->sigmay = 0.1;
485   user->rho    = 0.0;
486   user->t0     = 0.0;
487   user->tmax   = 2.0;
488   user->xmin   = -1.0;
489   user->xmax   = 10.0;
490   user->ymin   = -1.0;
491   user->ymax   = 10.0;
492   user->bc     = 0;
493 
494   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ws", &user->ws, &flg));
495   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-Inertia", &user->H, &flg));
496   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-Pmax", &user->Pmax, &flg));
497   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-PM_min", &user->PM_min, &flg));
498   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-lambda", &user->lambda, &flg));
499   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-q", &user->q, &flg));
500   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-mux", &user->mux, &flg));
501   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-sigmax", &user->sigmax, &flg));
502   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-muy", &user->muy, &flg));
503   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-sigmay", &user->sigmay, &flg));
504   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-rho", &user->rho, &flg));
505   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-t0", &user->t0, &flg));
506   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-tmax", &user->tmax, &flg));
507   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-xmin", &user->xmin, &flg));
508   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-xmax", &user->xmax, &flg));
509   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ymin", &user->ymin, &flg));
510   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ymax", &user->ymax, &flg));
511   PetscCall(PetscOptionsGetInt(NULL, NULL, "-bc_type", &user->bc, &flg));
512   user->muy = user->ws;
513   PetscFunctionReturn(PETSC_SUCCESS);
514 }
515 
516 /*TEST
517 
518    build:
519       requires: !complex
520 
521    test:
522       args: -nox -ts_max_steps 2
523       localrunfiles: petscopt_ex6
524       timeoutfactor: 4
525 
526 TEST*/
527