xref: /petsc/src/ts/tutorials/power_grid/ex7.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "Time-dependent PDE in 2d for calculating joint PDF. \n";
3 /*
4    p_t = -x_t*p_x -y_t*p_y + f(t)*p_yy
5    xmin < x < xmax, ymin < y < ymax;
6 
7    Boundary conditions Neumman using mirror values
8 
9    Note that x_t and y_t in the above are given functions of x and y; they are not derivatives of x and y.
10    x_t = (y - ws)  y_t = (ws/2H)*(Pm - Pmax*sin(x))
11 
12 */
13 
14 #include <petscdm.h>
15 #include <petscdmda.h>
16 #include <petscts.h>
17 
18 /*
19    User-defined data structures and routines
20 */
21 typedef struct {
22   PetscScalar ws;   /* Synchronous speed */
23   PetscScalar H;    /* Inertia constant */
24   PetscScalar D;    /* Damping constant */
25   PetscScalar Pmax; /* Maximum power output of generator */
26   PetscScalar PM_min; /* Mean mechanical power input */
27   PetscScalar lambda; /* correlation time */
28   PetscScalar q;      /* noise strength */
29   PetscScalar mux;    /* Initial average angle */
30   PetscScalar sigmax; /* Standard deviation of initial angle */
31   PetscScalar muy;    /* Average speed */
32   PetscScalar sigmay; /* standard deviation of initial speed */
33   PetscScalar rho;    /* Cross-correlation coefficient */
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   PetscScalar disper_coe; /* Dispersion coefficient */
41   DM          da;
42   PetscInt    st_width; /* Stencil width */
43   DMBoundaryType bx; /* x boundary type */
44   DMBoundaryType by; /* y boundary type */
45   PetscBool        nonoiseinitial;
46 } AppCtx;
47 
48 PetscErrorCode Parameter_settings(AppCtx*);
49 PetscErrorCode ini_bou(Vec,AppCtx*);
50 PetscErrorCode IFunction(TS,PetscReal,Vec,Vec,Vec,void*);
51 PetscErrorCode IJacobian(TS,PetscReal,Vec,Vec,PetscReal,Mat,Mat,void*);
52 PetscErrorCode PostStep(TS);
53 
54 int main(int argc, char **argv)
55 {
56   Vec            x;  /* Solution vector */
57   TS             ts;   /* Time-stepping context */
58   AppCtx         user; /* Application context */
59   PetscViewer    viewer;
60 
61   PetscFunctionBeginUser;
62   PetscCall(PetscInitialize(&argc,&argv,"petscopt_ex7", help));
63 
64   /* Get physics and time parameters */
65   PetscCall(Parameter_settings(&user));
66   /* Create a 2D DA with dof = 1 */
67   PetscCall(DMDACreate2d(PETSC_COMM_WORLD,user.bx,user.by,DMDA_STENCIL_STAR,4,4,PETSC_DECIDE,PETSC_DECIDE,1,user.st_width,NULL,NULL,&user.da));
68   PetscCall(DMSetFromOptions(user.da));
69   PetscCall(DMSetUp(user.da));
70   /* Set x and y coordinates */
71   PetscCall(DMDASetUniformCoordinates(user.da,user.xmin,user.xmax,user.ymin,user.ymax,0,0));
72   PetscCall(DMDASetCoordinateName(user.da,0,"X - the angle"));
73   PetscCall(DMDASetCoordinateName(user.da,1,"Y - the speed"));
74 
75   /* Get global vector x from DM  */
76   PetscCall(DMCreateGlobalVector(user.da,&x));
77 
78   PetscCall(ini_bou(x,&user));
79   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"ini_x",FILE_MODE_WRITE,&viewer));
80   PetscCall(VecView(x,viewer));
81   PetscCall(PetscViewerDestroy(&viewer));
82 
83   PetscCall(TSCreate(PETSC_COMM_WORLD,&ts));
84   PetscCall(TSSetDM(ts,user.da));
85   PetscCall(TSSetProblemType(ts,TS_NONLINEAR));
86   PetscCall(TSSetType(ts,TSARKIMEX));
87   PetscCall(TSSetIFunction(ts,NULL,IFunction,&user));
88   /*  PetscCall(TSSetIJacobian(ts,NULL,NULL,IJacobian,&user));  */
89   PetscCall(TSSetApplicationContext(ts,&user));
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(DMDestroy(&user.da));
101   PetscCall(TSDestroy(&ts));
102   PetscCall(PetscFinalize());
103   return 0;
104 }
105 
106 PetscErrorCode PostStep(TS ts)
107 {
108   Vec            X,gc;
109   AppCtx         *user;
110   PetscScalar    sum = 0,asum;
111   PetscReal      t,**p;
112   DMDACoor2d     **coors;
113   DM             cda;
114   PetscInt       i,j,xs,ys,xm,ym;
115 
116   PetscFunctionBegin;
117   PetscCall(TSGetApplicationContext(ts,&user));
118   PetscCall(TSGetTime(ts,&t));
119   PetscCall(TSGetSolution(ts,&X));
120 
121   PetscCall(DMGetCoordinateDM(user->da,&cda));
122   PetscCall(DMDAGetCorners(cda,&xs,&ys,0,&xm,&ym,0));
123   PetscCall(DMGetCoordinates(user->da,&gc));
124   PetscCall(DMDAVecGetArrayRead(cda,gc,&coors));
125   PetscCall(DMDAVecGetArrayRead(user->da,X,&p));
126   for (i=xs; i < xs+xm; i++) {
127     for (j=ys; j < ys+ym; j++) {
128       if (coors[j][i].y < 5) sum += p[j][i];
129     }
130   }
131   PetscCall(DMDAVecRestoreArrayRead(cda,gc,&coors));
132   PetscCall(DMDAVecRestoreArrayRead(user->da,X,&p));
133   PetscCallMPI(MPI_Allreduce(&sum,&asum,1,MPIU_SCALAR,MPIU_SUM,PetscObjectComm((PetscObject)ts)));
134   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"sum(p)*dw*dtheta at t = %f = %f\n",(double)t,(double)(asum)));
135   if (sum  < 1.0e-2) {
136     PetscCall(TSSetConvergedReason(ts,TS_CONVERGED_USER));
137     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Exiting TS as the integral of PDF is almost zero\n"));
138   }
139   PetscFunctionReturn(0);
140 }
141 
142 PetscErrorCode ini_bou(Vec X,AppCtx* user)
143 {
144   DM             cda;
145   DMDACoor2d     **coors;
146   PetscScalar    **p;
147   Vec            gc;
148   PetscInt       i,j;
149   PetscInt       xs,ys,xm,ym,M,N;
150   PetscScalar    xi,yi;
151   PetscScalar    sigmax=user->sigmax,sigmay=user->sigmay;
152   PetscScalar    rho   =user->rho;
153   PetscScalar    muy=user->muy,mux;
154   PetscMPIInt    rank;
155   PetscScalar    sum;
156 
157   PetscFunctionBeginUser;
158   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
159   PetscCall(DMDAGetInfo(user->da,NULL,&M,&N,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL));
160   user->dx = (user->xmax - user->xmin)/(M-1); user->dy = (user->ymax - user->ymin)/(N-1);
161   PetscCall(DMGetCoordinateDM(user->da,&cda));
162   PetscCall(DMGetCoordinates(user->da,&gc));
163   PetscCall(DMDAVecGetArray(cda,gc,&coors));
164   PetscCall(DMDAVecGetArray(user->da,X,&p));
165   PetscCall(DMDAGetCorners(cda,&xs,&ys,0,&xm,&ym,0));
166 
167   /* mux and muy need to be grid points in the x and y-direction otherwise the solution goes unstable
168      muy is set by choosing the y domain, no. of grid points along y-direction so that muy is a grid point
169      in the y-direction. We only modify mux here
170   */
171   mux = user->mux = coors[0][M/2+10].x; /* For -pi < x < pi, this should be some angle between 0 and pi/2 */
172   if (user->nonoiseinitial) {
173     for (i=xs; i < xs+xm; i++) {
174       for (j=ys; j < ys+ym; j++) {
175         xi = coors[j][i].x; yi = coors[j][i].y;
176         if ((xi == mux) && (yi == muy)) {
177           p[j][i] = 1.0;
178         }
179       }
180     }
181   } else {
182     /* Change PM_min accordingly */
183     user->PM_min = user->Pmax*PetscSinScalar(mux);
184     for (i=xs; i < xs+xm; i++) {
185       for (j=ys; j < ys+ym; j++) {
186         xi = coors[j][i].x; yi = coors[j][i].y;
187         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)));
188       }
189     }
190   }
191   PetscCall(DMDAVecRestoreArray(cda,gc,&coors));
192   PetscCall(DMDAVecRestoreArray(user->da,X,&p));
193   PetscCall(VecSum(X,&sum));
194   PetscCall(VecScale(X,1.0/sum));
195   PetscFunctionReturn(0);
196 }
197 
198 /* First advection term */
199 PetscErrorCode adv1(PetscScalar **p,PetscScalar y,PetscInt i,PetscInt j,PetscInt M,PetscScalar *p1,AppCtx *user)
200 {
201   PetscScalar f,fpos,fneg;
202   PetscFunctionBegin;
203   f   =  (y - user->ws);
204   fpos = PetscMax(f,0);
205   fneg = PetscMin(f,0);
206   if (user->st_width == 1) {
207     *p1 = fpos*(p[j][i] - p[j][i-1])/user->dx + fneg*(p[j][i+1] - p[j][i])/user->dx;
208   } else if (user->st_width == 2) {
209     *p1 = fpos*(3*p[j][i] - 4*p[j][i-1] + p[j][i-2])/(2*user->dx) + fneg*(-p[j][i+2] + 4*p[j][i+1] - 3*p[j][i])/(2*user->dx);
210   } else if (user->st_width == 3) {
211     *p1 = fpos*(2*p[j][i+1] + 3*p[j][i] - 6*p[j][i-1] + p[j][i-2])/(6*user->dx) + fneg*(-p[j][i+2] + 6*p[j][i+1] - 3*p[j][i] - 2*p[j][i-1])/(6*user->dx);
212   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"No support for wider stencils");
213   PetscFunctionReturn(0);
214 }
215 
216 /* Second advection term */
217 PetscErrorCode adv2(PetscScalar **p,PetscScalar x,PetscInt i,PetscInt j,PetscInt N,PetscScalar *p2,AppCtx *user)
218 {
219   PetscScalar f,fpos,fneg;
220   PetscFunctionBegin;
221   f   = (user->ws/(2*user->H))*(user->PM_min - user->Pmax*PetscSinScalar(x));
222   fpos = PetscMax(f,0);
223   fneg = PetscMin(f,0);
224   if (user->st_width == 1) {
225     *p2 = fpos*(p[j][i] - p[j-1][i])/user->dy + fneg*(p[j+1][i] - p[j][i])/user->dy;
226   } else if (user->st_width ==2) {
227     *p2 = fpos*(3*p[j][i] - 4*p[j-1][i] + p[j-2][i])/(2*user->dy) + fneg*(-p[j+2][i] + 4*p[j+1][i] - 3*p[j][i])/(2*user->dy);
228   } else if (user->st_width == 3) {
229     *p2 = fpos*(2*p[j+1][i] + 3*p[j][i] - 6*p[j-1][i] + p[j-2][i])/(6*user->dy) + fneg*(-p[j+2][i] + 6*p[j+1][i] - 3*p[j][i] - 2*p[j-1][i])/(6*user->dy);
230   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"No support for wider stencils");
231   PetscFunctionReturn(0);
232 }
233 
234 /* Diffusion term */
235 PetscErrorCode diffuse(PetscScalar **p,PetscInt i,PetscInt j,PetscReal t,PetscScalar *p_diff,AppCtx * user)
236 {
237   PetscFunctionBeginUser;
238   if (user->st_width == 1) {
239     *p_diff = user->disper_coe*((p[j-1][i] - 2*p[j][i] + p[j+1][i])/(user->dy*user->dy));
240   } else if (user->st_width == 2) {
241     *p_diff = user->disper_coe*((-p[j-2][i] + 16*p[j-1][i] - 30*p[j][i] + 16*p[j+1][i] - p[j+2][i])/(12.0*user->dy*user->dy));
242   } else if (user->st_width == 3) {
243     *p_diff = user->disper_coe*((2*p[j-3][i] - 27*p[j-2][i] + 270*p[j-1][i] - 490*p[j][i] + 270*p[j+1][i] - 27*p[j+2][i] + 2*p[j+3][i])/(180.0*user->dy*user->dy));
244   } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"No support for wider stencils");
245   PetscFunctionReturn(0);
246 }
247 
248 PetscErrorCode IFunction(TS ts,PetscReal t,Vec X,Vec Xdot,Vec F,void *ctx)
249 {
250   AppCtx         *user=(AppCtx*)ctx;
251   DM             cda;
252   DMDACoor2d     **coors;
253   PetscScalar    **p,**f,**pdot;
254   PetscInt       i,j;
255   PetscInt       xs,ys,xm,ym,M,N;
256   Vec            localX,gc,localXdot;
257   PetscScalar    p_adv1 = 0.0,p_adv2 = 0.0,p_diff; /* initialize to prevent incorrect compiler warnings */
258 
259   PetscFunctionBeginUser;
260   PetscCall(DMDAGetInfo(user->da,NULL,&M,&N,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL));
261   PetscCall(DMGetCoordinateDM(user->da,&cda));
262   PetscCall(DMDAGetCorners(cda,&xs,&ys,0,&xm,&ym,0));
263 
264   PetscCall(DMGetLocalVector(user->da,&localX));
265   PetscCall(DMGetLocalVector(user->da,&localXdot));
266 
267   PetscCall(DMGlobalToLocalBegin(user->da,X,INSERT_VALUES,localX));
268   PetscCall(DMGlobalToLocalEnd(user->da,X,INSERT_VALUES,localX));
269   PetscCall(DMGlobalToLocalBegin(user->da,Xdot,INSERT_VALUES,localXdot));
270   PetscCall(DMGlobalToLocalEnd(user->da,Xdot,INSERT_VALUES,localXdot));
271 
272   PetscCall(DMGetCoordinatesLocal(user->da,&gc));
273 
274   PetscCall(DMDAVecGetArrayRead(cda,gc,&coors));
275   PetscCall(DMDAVecGetArrayRead(user->da,localX,&p));
276   PetscCall(DMDAVecGetArrayRead(user->da,localXdot,&pdot));
277   PetscCall(DMDAVecGetArray(user->da,F,&f));
278 
279   user->disper_coe = PetscPowScalar((user->lambda*user->ws)/(2*user->H),2)*user->q*(1.0-PetscExpScalar(-t/user->lambda));
280   for (i=xs; i < xs+xm; i++) {
281     for (j=ys; j < ys+ym; j++) {
282       PetscCall(adv1(p,coors[j][i].y,i,j,M,&p_adv1,user));
283       PetscCall(adv2(p,coors[j][i].x,i,j,N,&p_adv2,user));
284       PetscCall(diffuse(p,i,j,t,&p_diff,user));
285       f[j][i] = -p_adv1 - p_adv2  + p_diff - pdot[j][i];
286     }
287   }
288   PetscCall(DMDAVecRestoreArrayRead(user->da,localX,&p));
289   PetscCall(DMDAVecRestoreArrayRead(user->da,localX,&pdot));
290   PetscCall(DMRestoreLocalVector(user->da,&localX));
291   PetscCall(DMRestoreLocalVector(user->da,&localXdot));
292   PetscCall(DMDAVecRestoreArray(user->da,F,&f));
293   PetscCall(DMDAVecRestoreArrayRead(cda,gc,&coors));
294 
295   PetscFunctionReturn(0);
296 }
297 
298 PetscErrorCode IJacobian(TS ts,PetscReal t,Vec X,Vec Xdot,PetscReal a,Mat J,Mat Jpre,void *ctx)
299 {
300   AppCtx         *user=(AppCtx*)ctx;
301   DM             cda;
302   DMDACoor2d     **coors;
303   PetscInt       i,j;
304   PetscInt       xs,ys,xm,ym,M,N;
305   Vec            gc;
306   PetscScalar    val[5],xi,yi;
307   MatStencil     row,col[5];
308   PetscScalar    c1,c3,c5,c1pos,c1neg,c3pos,c3neg;
309 
310   PetscFunctionBeginUser;
311   PetscCall(DMDAGetInfo(user->da,NULL,&M,&N,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL));
312   PetscCall(DMGetCoordinateDM(user->da,&cda));
313   PetscCall(DMDAGetCorners(cda,&xs,&ys,0,&xm,&ym,0));
314 
315   PetscCall(DMGetCoordinatesLocal(user->da,&gc));
316   PetscCall(DMDAVecGetArrayRead(cda,gc,&coors));
317   for (i=xs; i < xs+xm; i++) {
318     for (j=ys; j < ys+ym; j++) {
319       PetscInt nc = 0;
320       xi = coors[j][i].x; yi = coors[j][i].y;
321       row.i = i; row.j = j;
322       c1        = (yi-user->ws)/user->dx;
323       c1pos    = PetscMax(c1,0);
324       c1neg    = PetscMin(c1,0);
325       c3        = (user->ws/(2.0*user->H))*(user->PM_min - user->Pmax*PetscSinScalar(xi))/user->dy;
326       c3pos    = PetscMax(c3,0);
327       c3neg    = PetscMin(c3,0);
328       c5        = (PetscPowScalar((user->lambda*user->ws)/(2*user->H),2)*user->q*(1.0-PetscExpScalar(-t/user->lambda)))/(user->dy*user->dy);
329       col[nc].i = i-1; col[nc].j = j;   val[nc++] = c1pos;
330       col[nc].i = i+1; col[nc].j = j;   val[nc++] = -c1neg;
331       col[nc].i = i;   col[nc].j = j-1; val[nc++] = c3pos + c5;
332       col[nc].i = i;   col[nc].j = j+1; val[nc++] = -c3neg + c5;
333       col[nc].i = i;   col[nc].j = j;   val[nc++] = -c1pos + c1neg -c3pos + c3neg -2*c5 -a;
334       PetscCall(MatSetValuesStencil(Jpre,1,&row,nc,col,val,INSERT_VALUES));
335     }
336   }
337   PetscCall(DMDAVecRestoreArrayRead(cda,gc,&coors));
338 
339   PetscCall(MatAssemblyBegin(Jpre,MAT_FINAL_ASSEMBLY));
340   PetscCall(MatAssemblyEnd(Jpre,MAT_FINAL_ASSEMBLY));
341   if (J != Jpre) {
342     PetscCall(MatAssemblyBegin(J,MAT_FINAL_ASSEMBLY));
343     PetscCall(MatAssemblyEnd(J,MAT_FINAL_ASSEMBLY));
344   }
345   PetscFunctionReturn(0);
346 }
347 
348 PetscErrorCode Parameter_settings(AppCtx *user)
349 {
350   PetscBool      flg;
351 
352   PetscFunctionBeginUser;
353 
354   /* Set default parameters */
355   user->ws     = 1.0;
356   user->H      = 5.0;
357   user->Pmax   = 2.1;
358   user->PM_min = 1.0;
359   user->lambda = 0.1;
360   user->q      = 1.0;
361   user->mux    = PetscAsinScalar(user->PM_min/user->Pmax);
362   user->sigmax = 0.1;
363   user->sigmay = 0.1;
364   user->rho    = 0.0;
365   user->xmin   = -PETSC_PI;
366   user->xmax   =  PETSC_PI;
367   user->bx     = DM_BOUNDARY_PERIODIC;
368   user->by     = DM_BOUNDARY_MIRROR;
369   user->nonoiseinitial = PETSC_FALSE;
370 
371   /*
372      ymin of -3 seems to let the unstable solution move up and leave a zero in its wake
373      with an ymin of -1 the wake is never exactly zero
374   */
375   user->ymin   = -3.0;
376   user->ymax   = 10.0;
377   user->st_width = 1;
378 
379   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-ws",&user->ws,&flg));
380   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-Inertia",&user->H,&flg));
381   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-Pmax",&user->Pmax,&flg));
382   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-PM_min",&user->PM_min,&flg));
383   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-lambda",&user->lambda,&flg));
384   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-q",&user->q,&flg));
385   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-mux",&user->mux,&flg));
386   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-sigmax",&user->sigmax,&flg));
387   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-muy",&user->muy,&flg));
388   if (flg == 0) {
389     user->muy = user->ws;
390   }
391   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-sigmay",&user->sigmay,&flg));
392   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-rho",&user->rho,&flg));
393   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-xmin",&user->xmin,&flg));
394   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-xmax",&user->xmax,&flg));
395   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-ymin",&user->ymin,&flg));
396   PetscCall(PetscOptionsGetScalar(NULL,NULL,"-ymax",&user->ymax,&flg));
397   PetscCall(PetscOptionsGetInt(NULL,NULL,"-stencil_width",&user->st_width,&flg));
398   PetscCall(PetscOptionsGetEnum(NULL,NULL,"-bx",DMBoundaryTypes,(PetscEnum*)&user->bx,&flg));
399   PetscCall(PetscOptionsGetEnum(NULL,NULL,"-by",DMBoundaryTypes,(PetscEnum*)&user->by,&flg));
400   PetscCall(PetscOptionsGetBool(NULL,NULL,"-nonoiseinitial",&user->nonoiseinitial,&flg));
401 
402   PetscFunctionReturn(0);
403 }
404 
405 /*TEST
406 
407    build:
408       requires: !complex !single
409 
410    test:
411       args: -ts_max_steps 2
412       localrunfiles: petscopt_ex7
413 
414    test:
415       suffix: 2
416       args: -ts_max_steps 2 -snes_mf_operator
417       output_file: output/ex7_1.out
418       localrunfiles: petscopt_ex7
419       timeoutfactor: 2
420 
421    test:
422       suffix: 3
423       args: -ts_max_steps 2 -snes_mf -pc_type none
424       output_file: output/ex7_1.out
425       localrunfiles: petscopt_ex7
426       timeoutfactor: 2
427 
428 TEST*/
429