xref: /petsc/src/snes/impls/nasm/nasm.c (revision 009bbdc485cd9ad46be9940d3549e2dde9cdc322)
1 #include <petsc-private/snesimpl.h>             /*I   "petscsnes.h"   I*/
2 #include <petscdm.h>
3 
4 typedef struct {
5   PetscInt   n;                   /* local subdomains */
6   SNES       *subsnes;            /* nonlinear solvers for each subdomain */
7 
8   Vec        *x;                  /* solution vectors */
9   Vec        *xl;                 /* solution local vectors */
10   Vec        *y;                  /* step vectors */
11   Vec        *b;                  /* rhs vectors */
12 
13   VecScatter *oscatter;           /* scatter from global space to the subdomain global space */
14   VecScatter *iscatter;           /* scatter from global space to the nonoverlapping subdomain space */
15   VecScatter *gscatter;           /* scatter from global space to the subdomain local space */
16 
17   PCASMType type;                 /* ASM type */
18 
19   PetscBool  usesdm;               /* use the DM for setting up the subproblems */
20 } SNES_NASM;
21 
22 #undef __FUNCT__
23 #define __FUNCT__ "SNESReset_NASM"
24 PetscErrorCode SNESReset_NASM(SNES snes)
25 {
26   SNES_NASM      *nasm = (SNES_NASM *)snes->data;
27   PetscErrorCode ierr;
28   PetscInt       i;
29 
30   PetscFunctionBegin;
31   for (i=0;i<nasm->n;i++) {
32     if (nasm->xl) { ierr = VecDestroy(&nasm->xl[i]);CHKERRQ(ierr); }
33     if (nasm->x) { ierr = VecDestroy(&nasm->x[i]);CHKERRQ(ierr); }
34     if (nasm->y) { ierr = VecDestroy(&nasm->y[i]);CHKERRQ(ierr); }
35     if (nasm->b) { ierr = VecDestroy(&nasm->b[i]);CHKERRQ(ierr); }
36 
37     if (nasm->subsnes) { ierr = SNESDestroy(&nasm->subsnes[i]);CHKERRQ(ierr); }
38     if (nasm->oscatter) { ierr = VecScatterDestroy(&nasm->oscatter[i]);CHKERRQ(ierr); }
39     if (nasm->iscatter) { ierr = VecScatterDestroy(&nasm->iscatter[i]);CHKERRQ(ierr); }
40     if (nasm->gscatter) { ierr = VecScatterDestroy(&nasm->gscatter[i]);CHKERRQ(ierr); }
41   }
42 
43   if (nasm->x) {ierr = PetscFree(nasm->x);CHKERRQ(ierr);}
44   if (nasm->xl) {ierr = PetscFree(nasm->xl);CHKERRQ(ierr);}
45   if (nasm->y) {ierr = PetscFree(nasm->y);CHKERRQ(ierr);}
46   if (nasm->b) {ierr = PetscFree(nasm->b);CHKERRQ(ierr);}
47 
48   if (nasm->subsnes) {ierr = PetscFree(nasm->subsnes);CHKERRQ(ierr);}
49   if (nasm->oscatter) {ierr = PetscFree(nasm->oscatter);CHKERRQ(ierr);}
50   if (nasm->iscatter) {ierr = PetscFree(nasm->iscatter);CHKERRQ(ierr);}
51   if (nasm->gscatter) {ierr = PetscFree(nasm->gscatter);CHKERRQ(ierr);}
52   PetscFunctionReturn(0);
53 }
54 
55 #undef __FUNCT__
56 #define __FUNCT__ "SNESDestroy_NASM"
57 PetscErrorCode SNESDestroy_NASM(SNES snes)
58 {
59   PetscErrorCode ierr;
60 
61   PetscFunctionBegin;
62   ierr = SNESReset_NASM(snes);CHKERRQ(ierr);
63   ierr = PetscFree(snes->data);CHKERRQ(ierr);
64   PetscFunctionReturn(0);
65 }
66 
67 #undef __FUNCT__
68 #define __FUNCT__ "DMGlobalToLocalSubDomainDirichletHook_Private"
69 PetscErrorCode DMGlobalToLocalSubDomainDirichletHook_Private(DM dm,Vec g,InsertMode mode,Vec l,void *ctx)
70 {
71   PetscErrorCode ierr;
72   Vec bcs = (Vec)ctx;
73 
74   PetscFunctionBegin;
75   ierr = VecCopy(bcs,l);CHKERRQ(ierr);
76   PetscFunctionReturn(0);
77 }
78 
79 #undef __FUNCT__
80 #define __FUNCT__ "SNESSetUp_NASM"
81 PetscErrorCode SNESSetUp_NASM(SNES snes)
82 {
83   SNES_NASM      *nasm = (SNES_NASM *)snes->data;
84   PetscErrorCode ierr;
85   DM             dm,ddm;
86   DM             *subdms;
87   PetscInt       i;
88   const char     *optionsprefix;
89   Vec            F;
90 
91   PetscFunctionBegin;
92   if (!nasm->subsnes) {
93     ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
94     if (dm) {
95       nasm->usesdm = PETSC_TRUE;
96       ierr = DMCreateDomainDecomposition(dm,&nasm->n,PETSC_NULL,PETSC_NULL,PETSC_NULL,&subdms);CHKERRQ(ierr);
97       if (!subdms) {
98         ierr = DMCreateDomainDecompositionDM(dm,"default",&ddm);CHKERRQ(ierr);
99         if (!ddm) SETERRQ(((PetscObject)dm)->comm,PETSC_ERR_ARG_WRONGSTATE,"DM has no default decomposition defined.  Set subsolves manually with SNESNASMSetSubdomains().");
100         ierr = SNESSetDM(snes,ddm);CHKERRQ(ierr);
101         ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
102         ierr = DMCreateDomainDecomposition(dm,&nasm->n,PETSC_NULL,PETSC_NULL,PETSC_NULL,&subdms);CHKERRQ(ierr);
103       }
104       if (!subdms) SETERRQ(((PetscObject)dm)->comm,PETSC_ERR_ARG_WRONGSTATE,"DM has no default decomposition defined.  Set subsolves manually with SNESNASMSetSubdomains().");
105       ierr = DMCreateDomainDecompositionScatters(dm,nasm->n,subdms,&nasm->iscatter,&nasm->oscatter,&nasm->gscatter);CHKERRQ(ierr);
106 
107       ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr);
108       ierr = PetscMalloc(nasm->n*sizeof(SNES),&nasm->subsnes);CHKERRQ(ierr);
109 
110       for (i=0;i<nasm->n;i++) {
111         ierr = SNESCreate(PETSC_COMM_SELF,&nasm->subsnes[i]);CHKERRQ(ierr);
112         ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],optionsprefix);CHKERRQ(ierr);
113         ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],"sub_");CHKERRQ(ierr);
114         ierr = SNESSetDM(nasm->subsnes[i],subdms[i]);CHKERRQ(ierr);
115         ierr = SNESSetFromOptions(nasm->subsnes[i]);CHKERRQ(ierr);
116         ierr = DMDestroy(&subdms[i]);CHKERRQ(ierr);
117       }
118       ierr = PetscFree(subdms);CHKERRQ(ierr);
119     } else SETERRQ(((PetscObject)snes)->comm,PETSC_ERR_ARG_WRONGSTATE,"Cannot construct local problems automatically without a DM!");
120   } else SETERRQ(((PetscObject)snes)->comm,PETSC_ERR_ARG_WRONGSTATE,"Must set subproblems manually if there is no DM!");
121   /* allocate the global vectors */
122   ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->x);CHKERRQ(ierr);
123   ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->xl);CHKERRQ(ierr);
124   ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->y);CHKERRQ(ierr);
125   ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->b);CHKERRQ(ierr);
126 
127   for (i=0;i<nasm->n;i++) {
128     DM subdm;
129     ierr = SNESGetFunction(nasm->subsnes[i],&F,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
130     ierr = VecDuplicate(F,&nasm->x[i]);CHKERRQ(ierr);
131     ierr = VecDuplicate(F,&nasm->y[i]);CHKERRQ(ierr);
132     ierr = VecDuplicate(F,&nasm->b[i]);CHKERRQ(ierr);
133     ierr = SNESGetDM(nasm->subsnes[i],&subdm);CHKERRQ(ierr);
134     ierr = DMCreateLocalVector(subdm,&nasm->xl[i]);CHKERRQ(ierr);
135     ierr = DMGlobalToLocalHookAdd(subdm,DMGlobalToLocalSubDomainDirichletHook_Private,PETSC_NULL,nasm->xl[i]);CHKERRQ(ierr);
136   }
137   PetscFunctionReturn(0);
138 }
139 
140 #undef __FUNCT__
141 #define __FUNCT__ "SNESSetFromOptions_NASM"
142 PetscErrorCode SNESSetFromOptions_NASM(SNES snes)
143 {
144   PetscErrorCode ierr;
145   DM             dm,ddm;
146   char           ddm_name[1024];
147   PCASMType      asmtype;
148   const char *const SNESNASMTypes[]       = {"NONE","RESTRICT","INTERPOLATE","BASIC","PCASMType","PC_ASM_",0};
149   PetscBool      flg;
150   SNES_NASM      *nasm = (SNES_NASM *)snes->data;
151 
152   PetscFunctionBegin;
153   ierr = PetscOptionsHead("Nonlinear Additive Schwartz options");CHKERRQ(ierr);
154   ierr = PetscOptionsEnum("-snes_nasm_type","Type of restriction/extension","",SNESNASMTypes,(PetscEnum)nasm->type,(PetscEnum*)&asmtype,&flg);CHKERRQ(ierr);
155   if (flg) {nasm->type = asmtype;}
156   ierr = PetscOptionsString("-snes_nasm_decomposition", "Name of the DM defining the composition", "SNESSetDM", ddm_name, ddm_name,1024,&flg);CHKERRQ(ierr);
157   ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
158   if (flg) {
159     if (dm) {
160       ierr = DMCreateDomainDecompositionDM(dm, ddm_name, &ddm);CHKERRQ(ierr);
161       if (!ddm) SETERRQ1(((PetscObject)snes)->comm, PETSC_ERR_ARG_WRONGSTATE, "Unknown DM decomposition name %s", ddm_name);
162       ierr = PetscInfo(snes,"Using domain decomposition DM defined using options database\n");CHKERRQ(ierr);
163       ierr = SNESSetDM(snes,ddm);CHKERRQ(ierr);
164     } else SETERRQ(((PetscObject)snes)->comm, PETSC_ERR_ARG_WRONGSTATE, "No DM to decompose");
165   }
166   ierr = PetscOptionsTail();CHKERRQ(ierr);
167   PetscFunctionReturn(0);
168 }
169 
170 #undef __FUNCT__
171 #define __FUNCT__ "SNESView_NASM"
172 PetscErrorCode SNESView_NASM(SNES snes, PetscViewer viewer)
173 {
174   PetscFunctionBegin;
175   PetscFunctionReturn(0);
176 }
177 
178 #undef __FUNCT__
179 #define __FUNCT__ "SNESNASMSetSubdomains"
180 PetscErrorCode SNESNASMSetSubdomains(SNES snes,PetscInt n,SNES subsnes[],VecScatter iscatter[],VecScatter oscatter[],VecScatter gscatter[])
181 {
182   PetscErrorCode ierr;
183   PetscErrorCode (*f)(SNES,PetscInt,SNES*,VecScatter*,VecScatter*,VecScatter*);
184 
185   PetscFunctionBegin;
186   ierr = PetscObjectQueryFunction((PetscObject)snes,"SNESNASMSetSubdomains_C",(void (**)(void))&f);CHKERRQ(ierr);
187   ierr = (f)(snes,n,subsnes,iscatter,oscatter,gscatter);CHKERRQ(ierr);
188   PetscFunctionReturn(0);
189 }
190 
191 EXTERN_C_BEGIN
192 #undef __FUNCT__
193 #define __FUNCT__ "SNESNASMSetSubdomains_NASM"
194 PetscErrorCode SNESNASMSetSubdomains_NASM(SNES snes,PetscInt n,SNES subsnes[],VecScatter iscatter[],VecScatter oscatter[],VecScatter gscatter[])
195 {
196   PetscInt       i;
197   PetscErrorCode ierr;
198   SNES_NASM      *nasm = (SNES_NASM *)snes->data;
199 
200   PetscFunctionBegin;
201   if (snes->setupcalled)SETERRQ(((PetscObject)snes)->comm,PETSC_ERR_ARG_WRONGSTATE,"SNESNASMSetSubdomains() should be called before calling SNESSetUp().");
202 
203   /* tear down the previously set things */
204   ierr = SNESReset(snes);CHKERRQ(ierr);
205 
206   nasm->n        = n;
207   if (oscatter) {
208     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)oscatter[i]);CHKERRQ(ierr);}
209   }
210   if (iscatter) {
211     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)iscatter[i]);CHKERRQ(ierr);}
212   }
213   if (gscatter) {
214     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)gscatter[i]);CHKERRQ(ierr);}
215   }
216   if (oscatter) {
217     ierr = PetscMalloc(n*sizeof(IS),&nasm->oscatter);CHKERRQ(ierr);
218     for (i=0; i<n; i++) {
219       nasm->oscatter[i] = oscatter[i];
220     }
221   }
222   if (iscatter) {
223     ierr = PetscMalloc(n*sizeof(IS),&nasm->iscatter);CHKERRQ(ierr);
224     for (i=0; i<n; i++) {
225       nasm->iscatter[i] = iscatter[i];
226     }
227   }
228   if (gscatter) {
229     ierr = PetscMalloc(n*sizeof(IS),&nasm->gscatter);CHKERRQ(ierr);
230     for (i=0; i<n; i++) {
231       nasm->gscatter[i] = gscatter[i];
232     }
233   }
234 
235   if (subsnes) {
236     ierr = PetscMalloc(n*sizeof(SNES),&nasm->subsnes);CHKERRQ(ierr);
237     for (i=0; i<n; i++) {
238       nasm->subsnes[i] = subsnes[i];
239     }
240   }
241   PetscFunctionReturn(0);
242 }
243 EXTERN_C_END
244 
245 #undef __FUNCT__
246 #define __FUNCT__ "SNESNASMSolveLocal_Private"
247 PetscErrorCode SNESNASMSolveLocal_Private(SNES snes,Vec B,Vec Y,Vec X)
248 {
249   SNES_NASM      *nasm = (SNES_NASM *)snes->data;
250   SNES           subsnes;
251   PetscInt       i;
252   PetscErrorCode ierr;
253   Vec            Xlloc,Xl,Bl,Yl;
254   VecScatter     iscat,oscat,gscat;
255   DM             dm,subdm;
256 
257   PetscFunctionBegin;
258   ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
259   ierr = VecSet(Y,0);CHKERRQ(ierr);
260   for (i=0;i<nasm->n;i++) {
261     subsnes = nasm->subsnes[i];
262     ierr = SNESGetDM(subsnes,&subdm);CHKERRQ(ierr);
263     iscat = nasm->iscatter[i];
264     oscat = nasm->oscatter[i];
265     gscat = nasm->gscatter[i];
266     ierr = DMSubDomainRestrict(dm,oscat,gscat,subdm);CHKERRQ(ierr);
267 
268     /* scatter the solution to the local solution */
269     Xl = nasm->x[i];
270     Xlloc = nasm->xl[i];
271     Yl = nasm->y[i];
272 
273     ierr = VecScatterBegin(oscat,X,Xl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
274     ierr = VecScatterEnd(oscat,X,Xl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
275 
276     ierr = VecScatterBegin(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
277     ierr = VecScatterEnd(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
278 
279     ierr = VecCopy(Xl,Yl);CHKERRQ(ierr);
280 
281     if (B) {
282       /* scatter the RHS to the local RHS */
283       Bl = nasm->b[i];
284       ierr = VecScatterBegin(oscat,B,Bl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
285       ierr = VecScatterEnd(oscat,B,Bl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
286     } else {
287       Bl = PETSC_NULL;
288     }
289     ierr = SNESSolve(subsnes,Bl,Yl);CHKERRQ(ierr);
290 
291     ierr = VecAXPY(Yl,-1.0,Xl);CHKERRQ(ierr);
292 
293     if (nasm->type == PC_ASM_BASIC) {
294       ierr = VecScatterBegin(oscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
295       ierr = VecScatterEnd(oscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
296     } else if (nasm->type == PC_ASM_RESTRICT) {
297       ierr = VecScatterBegin(iscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
298       ierr = VecScatterEnd(iscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
299     } else SETERRQ(((PetscObject)snes)->comm,PETSC_ERR_ARG_WRONGSTATE,"Only basic and interpolate types are supported for SNESNASM");
300   }
301 
302   ierr = VecAssemblyBegin(Y);CHKERRQ(ierr);
303   ierr = VecAssemblyEnd(Y);CHKERRQ(ierr);
304 
305   ierr = VecAXPY(X,1.0,Y);CHKERRQ(ierr);
306   PetscFunctionReturn(0);
307 }
308 
309 #undef __FUNCT__
310 #define __FUNCT__ "SNESSolve_NASM"
311 PetscErrorCode SNESSolve_NASM(SNES snes)
312 {
313   Vec            F;
314   Vec            X;
315   Vec            B;
316   Vec            Y;
317   PetscInt       i;
318   PetscReal      fnorm;
319   PetscErrorCode ierr;
320   SNESNormType   normtype;
321 
322   PetscFunctionBegin;
323   X = snes->vec_sol;
324   Y = snes->vec_sol_update;
325   F = snes->vec_func;
326   B = snes->vec_rhs;
327 
328   ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
329   snes->iter = 0;
330   snes->norm = 0.;
331   ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
332   snes->reason = SNES_CONVERGED_ITERATING;
333   ierr = SNESGetNormType(snes, &normtype);CHKERRQ(ierr);
334   if (normtype == SNES_NORM_FUNCTION || normtype == SNES_NORM_INITIAL_ONLY || normtype == SNES_NORM_INITIAL_FINAL_ONLY) {
335     /* compute the initial function and preconditioned update delX */
336     if (!snes->vec_func_init_set) {
337       ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
338       if (snes->domainerror) {
339         snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
340         PetscFunctionReturn(0);
341       }
342     } else {
343       snes->vec_func_init_set = PETSC_FALSE;
344     }
345 
346     /* convergence test */
347     if (!snes->norm_init_set) {
348       ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
349       if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
350     } else {
351       fnorm = snes->norm_init;
352       snes->norm_init_set = PETSC_FALSE;
353     }
354     ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
355     snes->iter = 0;
356     snes->norm = fnorm;
357     ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
358     SNESLogConvHistory(snes,snes->norm,0);
359     ierr = SNESMonitor(snes,0,snes->norm);CHKERRQ(ierr);
360 
361     /* set parameter for default relative tolerance convergence test */
362     snes->ttol = fnorm*snes->rtol;
363 
364     /* test convergence */
365     ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
366     if (snes->reason) PetscFunctionReturn(0);
367   } else {
368     ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
369     SNESLogConvHistory(snes,snes->norm,0);
370     ierr = SNESMonitor(snes,0,snes->norm);CHKERRQ(ierr);
371   }
372 
373   /* Call general purpose update function */
374   if (snes->ops->update) {
375     ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
376   }
377 
378   for (i = 0; i < snes->max_its; i++) {
379     ierr = SNESNASMSolveLocal_Private(snes,B,Y,X);CHKERRQ(ierr);
380     if (normtype == SNES_NORM_FUNCTION || ((i == snes->max_its - 1) && (normtype == SNES_NORM_INITIAL_FINAL_ONLY || normtype == SNES_NORM_FINAL_ONLY))) {
381       ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
382       if (snes->domainerror) {
383         snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
384         PetscFunctionReturn(0);
385       }
386       ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
387       if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
388     }
389     /* Monitor convergence */
390     ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
391     snes->iter = i+1;
392     snes->norm = fnorm;
393     ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
394     SNESLogConvHistory(snes,snes->norm,0);
395     ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
396     /* Test for convergence */
397     if (normtype == SNES_NORM_FUNCTION) ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
398     if (snes->reason) PetscFunctionReturn(0);
399     /* Call general purpose update function */
400     if (snes->ops->update) {
401       ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
402     }
403   }
404   if (normtype == SNES_NORM_FUNCTION) {
405     if (i == snes->max_its) {
406       ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",snes->max_its);CHKERRQ(ierr);
407       if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
408     }
409   } else {
410     if (!snes->reason) snes->reason = SNES_CONVERGED_ITS; /* NASM is meant to be used as a preconditioner */
411   }
412   PetscFunctionReturn(0);
413 }
414 
415 /*MC
416   SNESNASM - Nonlinear Additive Schwartz
417 
418    Level: advanced
419 
420 .seealso: SNESCreate(), SNES, SNESSetType(), SNESType (for list of available types)
421 M*/
422 
423 EXTERN_C_BEGIN
424 #undef __FUNCT__
425 #define __FUNCT__ "SNESCreate_NASM"
426 PetscErrorCode SNESCreate_NASM(SNES snes)
427 {
428   SNES_NASM        *nasm;
429   PetscErrorCode ierr;
430 
431   PetscFunctionBegin;
432   ierr = PetscNewLog(snes, SNES_NASM, &nasm);CHKERRQ(ierr);
433   snes->data = (void*)nasm;
434 
435   nasm->n                 = PETSC_DECIDE;
436   nasm->subsnes           = 0;
437   nasm->x                 = 0;
438   nasm->xl                = 0;
439   nasm->y                 = 0;
440   nasm->b                 = 0;
441   nasm->oscatter          = 0;
442   nasm->iscatter          = 0;
443   nasm->gscatter          = 0;
444 
445   nasm->type              = PC_ASM_BASIC;
446 
447   snes->ops->destroy        = SNESDestroy_NASM;
448   snes->ops->setup          = SNESSetUp_NASM;
449   snes->ops->setfromoptions = SNESSetFromOptions_NASM;
450   snes->ops->view           = SNESView_NASM;
451   snes->ops->solve          = SNESSolve_NASM;
452   snes->ops->reset          = SNESReset_NASM;
453 
454   snes->usesksp             = PETSC_FALSE;
455   snes->usespc              = PETSC_FALSE;
456 
457   if (!snes->tolerancesset) {
458     snes->max_its             = 10000;
459     snes->max_funcs           = 10000;
460   }
461 
462   ierr = PetscObjectComposeFunctionDynamic((PetscObject)snes,"SNESNASMSetSubdomains_C","SNESNASMSetSubdomains_NASM",
463                   SNESNASMSetSubdomains_NASM);CHKERRQ(ierr);
464   PetscFunctionReturn(0);
465 }
466 EXTERN_C_END
467