xref: /petsc/src/ts/tutorials/power_grid/ex6.c (revision 0baf8eba40dbc839082666f9f7396a225d6f663c)
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 nonzero 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; /* v1,v2,v3,v4,v5,s1,s2,s3; */
167 
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; /* v1,v2,v3,v4,v5,s1,s2,s3; */
191 
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   *p_diff = user->disper_coe * ((p[j - 1][i] - 2 * p[j][i] + p[j + 1][i]) / (user->dy * user->dy));
216   PetscFunctionReturn(PETSC_SUCCESS);
217 }
218 
219 PetscErrorCode BoundaryConditions(PetscScalar **p, DMDACoor2d **coors, PetscInt i, PetscInt j, PetscInt M, PetscInt N, PetscScalar **f, AppCtx *user)
220 {
221   PetscScalar fwc, fthetac;
222   PetscScalar w = coors[j][i].y, theta = coors[j][i].x;
223 
224   PetscFunctionBeginUser;
225   if (user->bc == 0) { /* Natural boundary condition */
226     f[j][i] = p[j][i];
227   } else { /* Steady state boundary condition */
228     fthetac = user->ws / (2 * user->H) * (user->PM_min - user->Pmax * PetscSinScalar(theta));
229     fwc     = (w * w / 2.0 - user->ws * w);
230     if (i == 0 && j == 0) { /* left bottom corner */
231       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;
232     } else if (i == 0 && j == N - 1) { /* right bottom corner */
233       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;
234     } else if (i == M - 1 && j == 0) { /* left top corner */
235       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;
236     } else if (i == M - 1 && j == N - 1) { /* right top corner */
237       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;
238     } else if (i == 0) { /* Bottom edge */
239       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);
240     } else if (i == M - 1) { /* Top edge */
241       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);
242     } else if (j == 0) { /* Left edge */
243       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);
244     } else if (j == N - 1) { /* Right edge */
245       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);
246     }
247   }
248   PetscFunctionReturn(PETSC_SUCCESS);
249 }
250 
251 PetscErrorCode IFunction(TS ts, PetscReal t, Vec X, Vec Xdot, Vec F, void *ctx)
252 {
253   AppCtx       *user = (AppCtx *)ctx;
254   DM            cda;
255   DMDACoor2d  **coors;
256   PetscScalar **p, **f, **pdot;
257   PetscInt      i, j;
258   PetscInt      xs, ys, xm, ym, M, N;
259   Vec           localX, gc, localXdot;
260   PetscScalar   p_adv1, p_adv2, p_diff;
261 
262   PetscFunctionBeginUser;
263   PetscCall(DMDAGetInfo(user->da, NULL, &M, &N, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL));
264   PetscCall(DMGetCoordinateDM(user->da, &cda));
265   PetscCall(DMDAGetCorners(cda, &xs, &ys, 0, &xm, &ym, 0));
266 
267   PetscCall(DMGetLocalVector(user->da, &localX));
268   PetscCall(DMGetLocalVector(user->da, &localXdot));
269 
270   PetscCall(DMGlobalToLocalBegin(user->da, X, INSERT_VALUES, localX));
271   PetscCall(DMGlobalToLocalEnd(user->da, X, INSERT_VALUES, localX));
272   PetscCall(DMGlobalToLocalBegin(user->da, Xdot, INSERT_VALUES, localXdot));
273   PetscCall(DMGlobalToLocalEnd(user->da, Xdot, INSERT_VALUES, localXdot));
274 
275   PetscCall(DMGetCoordinatesLocal(user->da, &gc));
276 
277   PetscCall(DMDAVecGetArrayRead(cda, gc, &coors));
278   PetscCall(DMDAVecGetArrayRead(user->da, localX, &p));
279   PetscCall(DMDAVecGetArrayRead(user->da, localXdot, &pdot));
280   PetscCall(DMDAVecGetArray(user->da, F, &f));
281 
282   user->disper_coe = PetscPowScalar((user->lambda * user->ws) / (2 * user->H), 2) * user->q * (1.0 - PetscExpScalar(-t / user->lambda));
283   for (i = xs; i < xs + xm; i++) {
284     for (j = ys; j < ys + ym; j++) {
285       if (i == 0 || j == 0 || i == M - 1 || j == N - 1) {
286         PetscCall(BoundaryConditions(p, coors, i, j, M, N, f, user));
287       } else {
288         PetscCall(adv1(p, coors[j][i].y, i, j, M, &p_adv1, user));
289         PetscCall(adv2(p, coors[j][i].x, i, j, N, &p_adv2, user));
290         PetscCall(diffuse(p, i, j, t, &p_diff, user));
291         f[j][i] = -p_adv1 - p_adv2 + p_diff - pdot[j][i];
292       }
293     }
294   }
295   PetscCall(DMDAVecRestoreArrayRead(user->da, localX, &p));
296   PetscCall(DMDAVecRestoreArrayRead(user->da, localX, &pdot));
297   PetscCall(DMRestoreLocalVector(user->da, &localX));
298   PetscCall(DMRestoreLocalVector(user->da, &localXdot));
299   PetscCall(DMDAVecRestoreArray(user->da, F, &f));
300   PetscCall(DMDAVecRestoreArrayRead(cda, gc, &coors));
301   PetscFunctionReturn(PETSC_SUCCESS);
302 }
303 
304 PetscErrorCode IJacobian(TS ts, PetscReal t, Vec X, Vec Xdot, PetscReal a, Mat J, Mat Jpre, void *ctx)
305 {
306   AppCtx      *user = (AppCtx *)ctx;
307   DM           cda;
308   DMDACoor2d **coors;
309   PetscInt     i, j;
310   PetscInt     xs, ys, xm, ym, M, N;
311   Vec          gc;
312   PetscScalar  val[5], xi, yi;
313   MatStencil   row, col[5];
314   PetscScalar  c1, c3, c5;
315 
316   PetscFunctionBeginUser;
317   PetscCall(DMDAGetInfo(user->da, NULL, &M, &N, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL));
318   PetscCall(DMGetCoordinateDM(user->da, &cda));
319   PetscCall(DMDAGetCorners(cda, &xs, &ys, 0, &xm, &ym, 0));
320 
321   PetscCall(DMGetCoordinatesLocal(user->da, &gc));
322   PetscCall(DMDAVecGetArrayRead(cda, gc, &coors));
323   for (i = xs; i < xs + xm; i++) {
324     for (j = ys; j < ys + ym; j++) {
325       PetscInt nc = 0;
326       xi          = coors[j][i].x;
327       yi          = coors[j][i].y;
328       row.i       = i;
329       row.j       = j;
330       if (i == 0 || j == 0 || i == M - 1 || j == N - 1) {
331         if (user->bc == 0) {
332           col[nc].i = i;
333           col[nc].j = j;
334           val[nc++] = 1.0;
335         } else {
336           PetscScalar fthetac, fwc;
337           fthetac = user->ws / (2 * user->H) * (user->PM_min - user->Pmax * PetscSinScalar(xi));
338           fwc     = (yi * yi / 2.0 - user->ws * yi);
339           if (i == 0 && j == 0) {
340             col[nc].i = i + 1;
341             col[nc].j = j;
342             val[nc++] = fwc / user->dx;
343             col[nc].i = i;
344             col[nc].j = j + 1;
345             val[nc++] = -user->disper_coe / user->dy;
346             col[nc].i = i;
347             col[nc].j = j;
348             val[nc++] = -fwc / user->dx + fthetac + user->disper_coe / user->dy;
349           } else if (i == 0 && j == N - 1) {
350             col[nc].i = i + 1;
351             col[nc].j = j;
352             val[nc++] = fwc / user->dx;
353             col[nc].i = i;
354             col[nc].j = j - 1;
355             val[nc++] = user->disper_coe / user->dy;
356             col[nc].i = i;
357             col[nc].j = j;
358             val[nc++] = -fwc / user->dx + fthetac - user->disper_coe / user->dy;
359           } else if (i == M - 1 && j == 0) {
360             col[nc].i = i - 1;
361             col[nc].j = j;
362             val[nc++] = -fwc / user->dx;
363             col[nc].i = i;
364             col[nc].j = j + 1;
365             val[nc++] = -user->disper_coe / user->dy;
366             col[nc].i = i;
367             col[nc].j = j;
368             val[nc++] = fwc / user->dx + fthetac + user->disper_coe / user->dy;
369           } else if (i == M - 1 && j == N - 1) {
370             col[nc].i = i - 1;
371             col[nc].j = j;
372             val[nc++] = -fwc / user->dx;
373             col[nc].i = i;
374             col[nc].j = j - 1;
375             val[nc++] = user->disper_coe / user->dy;
376             col[nc].i = i;
377             col[nc].j = j;
378             val[nc++] = fwc / user->dx + fthetac - user->disper_coe / user->dy;
379           } else if (i == 0) {
380             col[nc].i = i + 1;
381             col[nc].j = j;
382             val[nc++] = fwc / user->dx;
383             col[nc].i = i;
384             col[nc].j = j + 1;
385             val[nc++] = -user->disper_coe / (2 * user->dy);
386             col[nc].i = i;
387             col[nc].j = j - 1;
388             val[nc++] = user->disper_coe / (2 * user->dy);
389             col[nc].i = i;
390             col[nc].j = j;
391             val[nc++] = -fwc / user->dx + fthetac;
392           } else if (i == M - 1) {
393             col[nc].i = i - 1;
394             col[nc].j = j;
395             val[nc++] = -fwc / user->dx;
396             col[nc].i = i;
397             col[nc].j = j + 1;
398             val[nc++] = -user->disper_coe / (2 * user->dy);
399             col[nc].i = i;
400             col[nc].j = j - 1;
401             val[nc++] = user->disper_coe / (2 * user->dy);
402             col[nc].i = i;
403             col[nc].j = j;
404             val[nc++] = fwc / user->dx + fthetac;
405           } else if (j == 0) {
406             col[nc].i = i + 1;
407             col[nc].j = j;
408             val[nc++] = fwc / (2 * user->dx);
409             col[nc].i = i - 1;
410             col[nc].j = j;
411             val[nc++] = -fwc / (2 * user->dx);
412             col[nc].i = i;
413             col[nc].j = j + 1;
414             val[nc++] = -user->disper_coe / user->dy;
415             col[nc].i = i;
416             col[nc].j = j;
417             val[nc++] = user->disper_coe / user->dy + fthetac;
418           } else if (j == N - 1) {
419             col[nc].i = i + 1;
420             col[nc].j = j;
421             val[nc++] = fwc / (2 * user->dx);
422             col[nc].i = i - 1;
423             col[nc].j = j;
424             val[nc++] = -fwc / (2 * user->dx);
425             col[nc].i = i;
426             col[nc].j = j - 1;
427             val[nc++] = user->disper_coe / user->dy;
428             col[nc].i = i;
429             col[nc].j = j;
430             val[nc++] = -user->disper_coe / user->dy + fthetac;
431           }
432         }
433       } else {
434         c1        = (yi - user->ws) / (2 * user->dx);
435         c3        = (user->ws / (2.0 * user->H)) * (user->PM_min - user->Pmax * PetscSinScalar(xi)) / (2 * user->dy);
436         c5        = (PetscPowScalar((user->lambda * user->ws) / (2 * user->H), 2) * user->q * (1.0 - PetscExpScalar(-t / user->lambda))) / (user->dy * user->dy);
437         col[nc].i = i - 1;
438         col[nc].j = j;
439         val[nc++] = c1;
440         col[nc].i = i + 1;
441         col[nc].j = j;
442         val[nc++] = -c1;
443         col[nc].i = i;
444         col[nc].j = j - 1;
445         val[nc++] = c3 + c5;
446         col[nc].i = i;
447         col[nc].j = j + 1;
448         val[nc++] = -c3 + c5;
449         col[nc].i = i;
450         col[nc].j = j;
451         val[nc++] = -2 * c5 - a;
452       }
453       PetscCall(MatSetValuesStencil(Jpre, 1, &row, nc, col, val, INSERT_VALUES));
454     }
455   }
456   PetscCall(DMDAVecRestoreArrayRead(cda, gc, &coors));
457 
458   PetscCall(MatAssemblyBegin(Jpre, MAT_FINAL_ASSEMBLY));
459   PetscCall(MatAssemblyEnd(Jpre, MAT_FINAL_ASSEMBLY));
460   if (J != Jpre) {
461     PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
462     PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
463   }
464   PetscFunctionReturn(PETSC_SUCCESS);
465 }
466 
467 PetscErrorCode Parameter_settings(AppCtx *user)
468 {
469   PetscBool flg;
470 
471   PetscFunctionBeginUser;
472   /* Set default parameters */
473   user->ws     = 1.0;
474   user->H      = 5.0;
475   user->Pmax   = 2.1;
476   user->PM_min = 1.0;
477   user->lambda = 0.1;
478   user->q      = 1.0;
479   user->mux    = PetscAsinScalar(user->PM_min / user->Pmax);
480   user->sigmax = 0.1;
481   user->sigmay = 0.1;
482   user->rho    = 0.0;
483   user->t0     = 0.0;
484   user->tmax   = 2.0;
485   user->xmin   = -1.0;
486   user->xmax   = 10.0;
487   user->ymin   = -1.0;
488   user->ymax   = 10.0;
489   user->bc     = 0;
490 
491   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ws", &user->ws, &flg));
492   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-Inertia", &user->H, &flg));
493   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-Pmax", &user->Pmax, &flg));
494   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-PM_min", &user->PM_min, &flg));
495   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-lambda", &user->lambda, &flg));
496   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-q", &user->q, &flg));
497   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-mux", &user->mux, &flg));
498   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-sigmax", &user->sigmax, &flg));
499   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-muy", &user->muy, &flg));
500   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-sigmay", &user->sigmay, &flg));
501   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-rho", &user->rho, &flg));
502   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-t0", &user->t0, &flg));
503   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-tmax", &user->tmax, &flg));
504   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-xmin", &user->xmin, &flg));
505   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-xmax", &user->xmax, &flg));
506   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ymin", &user->ymin, &flg));
507   PetscCall(PetscOptionsGetScalar(NULL, NULL, "-ymax", &user->ymax, &flg));
508   PetscCall(PetscOptionsGetInt(NULL, NULL, "-bc_type", &user->bc, &flg));
509   user->muy = user->ws;
510   PetscFunctionReturn(PETSC_SUCCESS);
511 }
512 
513 /*TEST
514 
515    build:
516       requires: !complex
517 
518    test:
519       args: -nox -ts_max_steps 2
520       localrunfiles: petscopt_ex6
521       timeoutfactor: 4
522 
523 TEST*/
524