xref: /petsc/src/snes/tests/ex69.c (revision 6a98f8dc3f2c9149905a87dc2e9d0fedaf64e09a)
1 
2 static char help[] = "Tests recovery from domain errors in MatMult() and PCApply()\n\n";
3 
4 /*
5       See src/ksp/ksp/tutorials/ex19.c from which this was copied
6 */
7 
8 #include <petscsnes.h>
9 #include <petscdm.h>
10 #include <petscdmda.h>
11 
12 /*
13    User-defined routines and data structures
14 */
15 typedef struct {
16   PetscScalar u,v,omega,temp;
17 } Field;
18 
19 PetscErrorCode FormFunctionLocal(DMDALocalInfo*,Field**,Field**,void*);
20 
21 typedef struct {
22   PetscReal   lidvelocity,prandtl,grashof;  /* physical parameters */
23   PetscBool   draw_contours;                /* flag - 1 indicates drawing contours */
24   PetscBool   errorindomain;
25   PetscBool   errorindomainmf;
26   SNES        snes;
27 } AppCtx;
28 
29 typedef struct {
30   Mat Jmf;
31 } MatShellCtx;
32 
33 extern PetscErrorCode FormInitialGuess(AppCtx*,DM,Vec);
34 extern PetscErrorCode MatMult_MyShell(Mat,Vec,Vec);
35 extern PetscErrorCode MatAssemblyEnd_MyShell(Mat,MatAssemblyType);
36 extern PetscErrorCode PCApply_MyShell(PC,Vec,Vec);
37 extern PetscErrorCode SNESComputeJacobian_MyShell(SNES,Vec,Mat,Mat,void*);
38 
39 int main(int argc,char **argv)
40 {
41   AppCtx         user;                /* user-defined work context */
42   PetscInt       mx,my;
43   PetscErrorCode ierr;
44   MPI_Comm       comm;
45   DM             da;
46   Vec            x;
47   Mat            J = NULL,Jmf = NULL;
48   MatShellCtx    matshellctx;
49   PetscInt       mlocal,nlocal;
50   PC             pc;
51   KSP            ksp;
52   PetscBool      errorinmatmult = PETSC_FALSE,errorinpcapply = PETSC_FALSE,errorinpcsetup = PETSC_FALSE;
53 
54   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
55   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_matmult",&errorinmatmult,NULL);CHKERRQ(ierr);
56   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_pcapply",&errorinpcapply,NULL);CHKERRQ(ierr);
57   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_pcsetup",&errorinpcsetup,NULL);CHKERRQ(ierr);
58   user.errorindomain = PETSC_FALSE;
59   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_domain",&user.errorindomain,NULL);CHKERRQ(ierr);
60   user.errorindomainmf = PETSC_FALSE;
61   ierr = PetscOptionsGetBool(NULL,NULL,"-error_in_domainmf",&user.errorindomainmf,NULL);CHKERRQ(ierr);
62 
63   comm = PETSC_COMM_WORLD;
64   ierr = SNESCreate(comm,&user.snes);CHKERRQ(ierr);
65 
66   /*
67       Create distributed array object to manage parallel grid and vectors
68       for principal unknowns (x) and governing residuals (f)
69   */
70   ierr = DMDACreate2d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,4,4,PETSC_DECIDE,PETSC_DECIDE,4,1,0,0,&da);CHKERRQ(ierr);
71   ierr = DMSetFromOptions(da);CHKERRQ(ierr);
72   ierr = DMSetUp(da);CHKERRQ(ierr);
73   ierr = SNESSetDM(user.snes,da);CHKERRQ(ierr);
74 
75   ierr = DMDAGetInfo(da,0,&mx,&my,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,
76                      PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE);CHKERRQ(ierr);
77   /*
78      Problem parameters (velocity of lid, prandtl, and grashof numbers)
79   */
80   user.lidvelocity = 1.0/(mx*my);
81   user.prandtl     = 1.0;
82   user.grashof     = 1.0;
83 
84   ierr = PetscOptionsGetReal(NULL,NULL,"-lidvelocity",&user.lidvelocity,NULL);CHKERRQ(ierr);
85   ierr = PetscOptionsGetReal(NULL,NULL,"-prandtl",&user.prandtl,NULL);CHKERRQ(ierr);
86   ierr = PetscOptionsGetReal(NULL,NULL,"-grashof",&user.grashof,NULL);CHKERRQ(ierr);
87   ierr = PetscOptionsHasName(NULL,NULL,"-contours",&user.draw_contours);CHKERRQ(ierr);
88 
89   ierr = DMDASetFieldName(da,0,"x_velocity");CHKERRQ(ierr);
90   ierr = DMDASetFieldName(da,1,"y_velocity");CHKERRQ(ierr);
91   ierr = DMDASetFieldName(da,2,"Omega");CHKERRQ(ierr);
92   ierr = DMDASetFieldName(da,3,"temperature");CHKERRQ(ierr);
93 
94   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
95      Create user context, set problem data, create vector data structures.
96      Also, compute the initial guess.
97      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
98 
99   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
100      Create nonlinear solver context
101 
102      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
103   ierr = DMSetApplicationContext(da,&user);CHKERRQ(ierr);
104   ierr = DMDASNESSetFunctionLocal(da,INSERT_VALUES,(PetscErrorCode (*)(DMDALocalInfo*,void*,void*,void*))FormFunctionLocal,&user);CHKERRQ(ierr);
105 
106   if (errorinmatmult) {
107     ierr = MatCreateSNESMF(user.snes,&Jmf);CHKERRQ(ierr);
108     ierr = MatSetFromOptions(Jmf);CHKERRQ(ierr);
109     ierr = MatGetLocalSize(Jmf,&mlocal,&nlocal);CHKERRQ(ierr);
110     matshellctx.Jmf = Jmf;
111     ierr = MatCreateShell(PetscObjectComm((PetscObject)Jmf),mlocal,nlocal,PETSC_DECIDE,PETSC_DECIDE,&matshellctx,&J);CHKERRQ(ierr);
112     ierr = MatShellSetOperation(J,MATOP_MULT,(void (*)(void))MatMult_MyShell);CHKERRQ(ierr);
113     ierr = MatShellSetOperation(J,MATOP_ASSEMBLY_END,(void (*)(void))MatAssemblyEnd_MyShell);CHKERRQ(ierr);
114     ierr = SNESSetJacobian(user.snes,J,J,MatMFFDComputeJacobian,NULL);CHKERRQ(ierr);
115   }
116 
117   ierr = SNESSetFromOptions(user.snes);CHKERRQ(ierr);
118   ierr = PetscPrintf(comm,"lid velocity = %g, prandtl # = %g, grashof # = %g\n",(double)user.lidvelocity,(double)user.prandtl,(double)user.grashof);CHKERRQ(ierr);
119 
120   if (errorinpcapply) {
121     ierr = SNESGetKSP(user.snes,&ksp);CHKERRQ(ierr);
122     ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
123     ierr = PCSetType(pc,PCSHELL);CHKERRQ(ierr);
124     ierr = PCShellSetApply(pc,PCApply_MyShell);CHKERRQ(ierr);
125   }
126 
127   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
128      Solve the nonlinear system
129      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
130   ierr = DMCreateGlobalVector(da,&x);CHKERRQ(ierr);
131   ierr = FormInitialGuess(&user,da,x);CHKERRQ(ierr);
132 
133   if (errorinpcsetup) {
134     ierr = SNESSetUp(user.snes);CHKERRQ(ierr);
135     ierr = SNESSetJacobian(user.snes,NULL,NULL,SNESComputeJacobian_MyShell,NULL);CHKERRQ(ierr);
136   }
137   ierr = SNESSolve(user.snes,NULL,x);CHKERRQ(ierr);
138 
139 
140   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
141      Free work space.  All PETSc objects should be destroyed when they
142      are no longer needed.
143      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
144   ierr = MatDestroy(&J);CHKERRQ(ierr);
145   ierr = MatDestroy(&Jmf);CHKERRQ(ierr);
146   ierr = VecDestroy(&x);CHKERRQ(ierr);
147   ierr = DMDestroy(&da);CHKERRQ(ierr);
148   ierr = SNESDestroy(&user.snes);CHKERRQ(ierr);
149   ierr = PetscFinalize();
150   return ierr;
151 }
152 
153 /* ------------------------------------------------------------------- */
154 
155 
156 /*
157    FormInitialGuess - Forms initial approximation.
158 
159    Input Parameters:
160    user - user-defined application context
161    X - vector
162 
163    Output Parameter:
164    X - vector
165 */
166 PetscErrorCode FormInitialGuess(AppCtx *user,DM da,Vec X)
167 {
168   PetscInt       i,j,mx,xs,ys,xm,ym;
169   PetscErrorCode ierr;
170   PetscReal      grashof,dx;
171   Field          **x;
172 
173   PetscFunctionBeginUser;
174   grashof = user->grashof;
175 
176   ierr = DMDAGetInfo(da,0,&mx,0,0,0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
177   dx   = 1.0/(mx-1);
178 
179   /*
180      Get local grid boundaries (for 2-dimensional DMDA):
181        xs, ys   - starting grid indices (no ghost points)
182        xm, ym   - widths of local grid (no ghost points)
183   */
184   ierr = DMDAGetCorners(da,&xs,&ys,NULL,&xm,&ym,NULL);CHKERRQ(ierr);
185 
186   /*
187      Get a pointer to vector data.
188        - For default PETSc vectors, VecGetArray() returns a pointer to
189          the data array.  Otherwise, the routine is implementation dependent.
190        - You MUST call VecRestoreArray() when you no longer need access to
191          the array.
192   */
193   ierr = DMDAVecGetArray(da,X,&x);CHKERRQ(ierr);
194 
195   /*
196      Compute initial guess over the locally owned part of the grid
197      Initial condition is motionless fluid and equilibrium temperature
198   */
199   for (j=ys; j<ys+ym; j++) {
200     for (i=xs; i<xs+xm; i++) {
201       x[j][i].u     = 0.0;
202       x[j][i].v     = 0.0;
203       x[j][i].omega = 0.0;
204       x[j][i].temp  = (grashof>0)*i*dx;
205     }
206   }
207 
208   /*
209      Restore vector
210   */
211   ierr = DMDAVecRestoreArray(da,X,&x);CHKERRQ(ierr);
212   PetscFunctionReturn(0);
213 }
214 
215 PetscErrorCode FormFunctionLocal(DMDALocalInfo *info,Field **x,Field **f,void *ptr)
216 {
217   AppCtx          *user = (AppCtx*)ptr;
218   PetscErrorCode  ierr;
219   PetscInt        xints,xinte,yints,yinte,i,j;
220   PetscReal       hx,hy,dhx,dhy,hxdhy,hydhx;
221   PetscReal       grashof,prandtl,lid;
222   PetscScalar     u,uxx,uyy,vx,vy,avx,avy,vxp,vxm,vyp,vym;
223   static PetscInt fail = 0;
224 
225   PetscFunctionBeginUser;
226   if ((fail++ > 7 && user->errorindomainmf) || (fail++ > 36 && user->errorindomain)){
227     PetscMPIInt rank;
228     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)user->snes),&rank);CHKERRQ(ierr);
229     if (!rank) {
230       ierr = SNESSetFunctionDomainError(user->snes);CHKERRQ(ierr);
231     }
232   }
233   grashof = user->grashof;
234   prandtl = user->prandtl;
235   lid     = user->lidvelocity;
236 
237   /*
238      Define mesh intervals ratios for uniform grid.
239 
240      Note: FD formulae below are normalized by multiplying through by
241      local volume element (i.e. hx*hy) to obtain coefficients O(1) in two dimensions.
242 
243 
244   */
245   dhx   = (PetscReal)(info->mx-1);  dhy = (PetscReal)(info->my-1);
246   hx    = 1.0/dhx;                   hy = 1.0/dhy;
247   hxdhy = hx*dhy;                 hydhx = hy*dhx;
248 
249   xints = info->xs; xinte = info->xs+info->xm; yints = info->ys; yinte = info->ys+info->ym;
250 
251   /* Test whether we are on the bottom edge of the global array */
252   if (yints == 0) {
253     j     = 0;
254     yints = yints + 1;
255     /* bottom edge */
256     for (i=info->xs; i<info->xs+info->xm; i++) {
257       f[j][i].u     = x[j][i].u;
258       f[j][i].v     = x[j][i].v;
259       f[j][i].omega = x[j][i].omega + (x[j+1][i].u - x[j][i].u)*dhy;
260       f[j][i].temp  = x[j][i].temp-x[j+1][i].temp;
261     }
262   }
263 
264   /* Test whether we are on the top edge of the global array */
265   if (yinte == info->my) {
266     j     = info->my - 1;
267     yinte = yinte - 1;
268     /* top edge */
269     for (i=info->xs; i<info->xs+info->xm; i++) {
270       f[j][i].u     = x[j][i].u - lid;
271       f[j][i].v     = x[j][i].v;
272       f[j][i].omega = x[j][i].omega + (x[j][i].u - x[j-1][i].u)*dhy;
273       f[j][i].temp  = x[j][i].temp-x[j-1][i].temp;
274     }
275   }
276 
277   /* Test whether we are on the left edge of the global array */
278   if (xints == 0) {
279     i     = 0;
280     xints = xints + 1;
281     /* left edge */
282     for (j=info->ys; j<info->ys+info->ym; j++) {
283       f[j][i].u     = x[j][i].u;
284       f[j][i].v     = x[j][i].v;
285       f[j][i].omega = x[j][i].omega - (x[j][i+1].v - x[j][i].v)*dhx;
286       f[j][i].temp  = x[j][i].temp;
287     }
288   }
289 
290   /* Test whether we are on the right edge of the global array */
291   if (xinte == info->mx) {
292     i     = info->mx - 1;
293     xinte = xinte - 1;
294     /* right edge */
295     for (j=info->ys; j<info->ys+info->ym; j++) {
296       f[j][i].u     = x[j][i].u;
297       f[j][i].v     = x[j][i].v;
298       f[j][i].omega = x[j][i].omega - (x[j][i].v - x[j][i-1].v)*dhx;
299       f[j][i].temp  = x[j][i].temp - (PetscReal)(grashof>0);
300     }
301   }
302 
303   /* Compute over the interior points */
304   for (j=yints; j<yinte; j++) {
305     for (i=xints; i<xinte; i++) {
306 
307       /*
308        convective coefficients for upwinding
309       */
310       vx  = x[j][i].u; avx = PetscAbsScalar(vx);
311       vxp = .5*(vx+avx); vxm = .5*(vx-avx);
312       vy  = x[j][i].v; avy = PetscAbsScalar(vy);
313       vyp = .5*(vy+avy); vym = .5*(vy-avy);
314 
315       /* U velocity */
316       u         = x[j][i].u;
317       uxx       = (2.0*u - x[j][i-1].u - x[j][i+1].u)*hydhx;
318       uyy       = (2.0*u - x[j-1][i].u - x[j+1][i].u)*hxdhy;
319       f[j][i].u = uxx + uyy - .5*(x[j+1][i].omega-x[j-1][i].omega)*hx;
320 
321       /* V velocity */
322       u         = x[j][i].v;
323       uxx       = (2.0*u - x[j][i-1].v - x[j][i+1].v)*hydhx;
324       uyy       = (2.0*u - x[j-1][i].v - x[j+1][i].v)*hxdhy;
325       f[j][i].v = uxx + uyy + .5*(x[j][i+1].omega-x[j][i-1].omega)*hy;
326 
327       /* Omega */
328       u             = x[j][i].omega;
329       uxx           = (2.0*u - x[j][i-1].omega - x[j][i+1].omega)*hydhx;
330       uyy           = (2.0*u - x[j-1][i].omega - x[j+1][i].omega)*hxdhy;
331       f[j][i].omega = uxx + uyy + (vxp*(u - x[j][i-1].omega) + vxm*(x[j][i+1].omega - u))*hy +
332                       (vyp*(u - x[j-1][i].omega) + vym*(x[j+1][i].omega - u))*hx -
333                       .5*grashof*(x[j][i+1].temp - x[j][i-1].temp)*hy;
334 
335       /* Temperature */
336       u            = x[j][i].temp;
337       uxx          = (2.0*u - x[j][i-1].temp - x[j][i+1].temp)*hydhx;
338       uyy          = (2.0*u - x[j-1][i].temp - x[j+1][i].temp)*hxdhy;
339       f[j][i].temp =  uxx + uyy  + prandtl*((vxp*(u - x[j][i-1].temp) + vxm*(x[j][i+1].temp - u))*hy +
340                                             (vyp*(u - x[j-1][i].temp) + vym*(x[j+1][i].temp - u))*hx);
341     }
342   }
343 
344   /*
345      Flop count (multiply-adds are counted as 2 operations)
346   */
347   ierr = PetscLogFlops(84.0*info->ym*info->xm);CHKERRQ(ierr);
348   PetscFunctionReturn(0);
349 }
350 
351 PetscErrorCode MatMult_MyShell(Mat A,Vec x,Vec y)
352 {
353   PetscErrorCode  ierr;
354   MatShellCtx     *matshellctx;
355   static PetscInt fail = 0;
356 
357   PetscFunctionBegin;
358   ierr = MatShellGetContext(A,&matshellctx);CHKERRQ(ierr);
359   ierr = MatMult(matshellctx->Jmf,x,y);CHKERRQ(ierr);
360   if (fail++ > 5) {
361     PetscMPIInt rank;
362     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)A),&rank);CHKERRQ(ierr);
363     if (!rank) {ierr = VecSetInf(y);CHKERRQ(ierr);}
364   }
365   PetscFunctionReturn(0);
366 }
367 
368 PetscErrorCode MatAssemblyEnd_MyShell(Mat A,MatAssemblyType tp)
369 {
370   PetscErrorCode ierr;
371   MatShellCtx    *matshellctx;
372 
373   PetscFunctionBegin;
374   ierr = MatShellGetContext(A,&matshellctx);CHKERRQ(ierr);
375   ierr = MatAssemblyEnd(matshellctx->Jmf,tp);CHKERRQ(ierr);
376   PetscFunctionReturn(0);
377 }
378 
379 PetscErrorCode PCApply_MyShell(PC pc,Vec x,Vec y)
380 {
381   PetscErrorCode ierr;
382   static PetscInt fail = 0;
383 
384   PetscFunctionBegin;
385   ierr = VecCopy(x,y);CHKERRQ(ierr);
386   if (fail++ > 3) {
387     PetscMPIInt rank;
388     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)pc),&rank);CHKERRQ(ierr);
389     if (!rank) {ierr = VecSetInf(y);CHKERRQ(ierr);}
390   }
391   PetscFunctionReturn(0);
392 }
393 
394 PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES,Vec,Mat,Mat,void*);
395 
396 PetscErrorCode SNESComputeJacobian_MyShell(SNES snes,Vec X,Mat A,Mat B,void *ctx)
397 {
398   static PetscInt fail = 0;
399   PetscErrorCode  ierr;
400 
401   PetscFunctionBegin;
402   ierr = SNESComputeJacobian_DMDA(snes,X,A,B,ctx);CHKERRQ(ierr);
403   if (fail++ > 0) {
404     ierr = MatZeroEntries(A);CHKERRQ(ierr);
405   }
406   PetscFunctionReturn(0);
407 }
408 
409 
410 /*TEST
411 
412    test:
413       args: -snes_converged_reason -ksp_converged_reason
414 
415    test:
416       suffix: 2
417       args: -snes_converged_reason -ksp_converged_reason -error_in_matmult
418 
419    test:
420       suffix: 3
421       args: -snes_converged_reason -ksp_converged_reason -error_in_pcapply
422 
423    test:
424       suffix: 4
425       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup
426 
427    test:
428       suffix: 5
429       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup -pc_type bjacobi
430 
431    test:
432       suffix: 5_fieldsplit
433       args: -snes_converged_reason -ksp_converged_reason -error_in_pcsetup -pc_type fieldsplit
434       output_file: output/ex69_5.out
435 
436    test:
437       suffix: 6
438       args: -snes_converged_reason -ksp_converged_reason -error_in_domainmf -snes_mf -pc_type none
439 
440    test:
441       suffix: 7
442       args: -snes_converged_reason -ksp_converged_reason -error_in_domain
443 
444    test:
445       suffix: 8
446       args: -snes_converged_reason -ksp_converged_reason -error_in_domain -snes_mf -pc_type none
447 
448 TEST*/
449