xref: /petsc/src/dm/impls/da/grglvis.c (revision aab5bcd8e18f0808071e10849b7b64c13bdb175c)
1 /* Routines to visualize DMDAs and fields through GLVis */
2 
3 #include <petsc/private/dmdaimpl.h>
4 #include <petsc/private/glvisviewerimpl.h>
5 
6 typedef struct {
7   Vec xlocal;
8 } DMDAGLVisViewerCtx;
9 
10 static PetscErrorCode DMDADestroyGLVisViewerCtx_Private(void *vctx)
11 {
12   DMDAGLVisViewerCtx *ctx = (DMDAGLVisViewerCtx*)vctx;
13   PetscErrorCode     ierr;
14 
15   PetscFunctionBegin;
16   ierr = VecDestroy(&ctx->xlocal);CHKERRQ(ierr);
17   ierr = PetscFree(vctx);CHKERRQ(ierr);
18   PetscFunctionReturn(0);
19 }
20 
21 /* all but the last proc per dimension claim the ghosted node */
22 static PetscErrorCode DMDAGetNumElementsGhosted(DM da, PetscInt *nex, PetscInt *ney, PetscInt *nez)
23 {
24   PetscInt       M,N,P,sx,sy,sz,ien,jen,ken;
25   PetscErrorCode ierr;
26 
27   PetscFunctionBegin;
28   /* Appease -Wmaybe-uninitialized */
29   if (nex) *nex = -1;
30   if (ney) *ney = -1;
31   if (nez) *nez = -1;
32   ierr = DMDAGetInfo(da,NULL,&M,&N,&P,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
33   ierr = DMDAGetCorners(da,&sx,&sy,&sz,&ien,&jen,&ken);CHKERRQ(ierr);
34   if (sx+ien == M) ien--;
35   if (sy+jen == N) jen--;
36   if (sz+ken == P) ken--;
37   if (nex) *nex = ien;
38   if (ney) *ney = jen;
39   if (nez) *nez = ken;
40   PetscFunctionReturn(0);
41 }
42 
43 /* inherits number of vertices from DMDAGetNumElementsGhosted */
44 static PetscErrorCode DMDAGetNumVerticesGhosted(DM da, PetscInt *nvx, PetscInt *nvy, PetscInt *nvz)
45 {
46   PetscInt       ien,jen,ken,dim;
47   PetscErrorCode ierr;
48 
49   PetscFunctionBegin;
50   ierr = DMGetDimension(da,&dim);CHKERRQ(ierr);
51   ierr = DMDAGetNumElementsGhosted(da,&ien,&jen,&ken);CHKERRQ(ierr);
52   ien  = ien+1;
53   jen  = dim > 1 ? jen+1 : 1;
54   ken  = dim > 2 ? ken+1 : 1;
55   if (nvx) *nvx = ien;
56   if (nvy) *nvy = jen;
57   if (nvz) *nvz = ken;
58   PetscFunctionReturn(0);
59 }
60 
61 static PetscErrorCode DMDASampleGLVisFields_Private(PetscObject oX, PetscInt nf, PetscObject oXf[], void *vctx)
62 {
63   DM                 da;
64   DMDAGLVisViewerCtx *ctx = (DMDAGLVisViewerCtx*)vctx;
65   const PetscScalar  *array;
66   PetscScalar        **arrayf;
67   PetscInt           i,f,ii,ien,jen,ken,ie,je,ke,bs,*bss;
68   PetscInt           sx,sy,sz,gsx,gsy,gsz,ist,jst,kst,gm,gn,gp;
69   PetscErrorCode     ierr;
70 
71   PetscFunctionBegin;
72   ierr = VecGetDM(ctx->xlocal,&da);CHKERRQ(ierr);
73   if (!da) SETERRQ(PetscObjectComm(oX),PETSC_ERR_ARG_WRONG,"Vector not generated from a DMDA");
74   ierr = VecGetBlockSize(ctx->xlocal,&bs);CHKERRQ(ierr);
75   ierr = DMGlobalToLocalBegin(da,(Vec)oX,INSERT_VALUES,ctx->xlocal);CHKERRQ(ierr);
76   ierr = DMGlobalToLocalEnd(da,(Vec)oX,INSERT_VALUES,ctx->xlocal);CHKERRQ(ierr);
77   ierr = DMDAGetNumVerticesGhosted(da,&ien,&jen,&ken);CHKERRQ(ierr);
78   ierr = DMDAGetGhostCorners(da,&gsx,&gsy,&gsz,&gm,&gn,&gp);CHKERRQ(ierr);
79   ierr = DMDAGetCorners(da,&sx,&sy,&sz,NULL,NULL,NULL);CHKERRQ(ierr);
80   kst  = gsz != sz ? 1 : 0;
81   jst  = gsy != sy ? 1 : 0;
82   ist  = gsx != sx ? 1 : 0;
83   ierr = PetscMalloc2(nf,&arrayf,nf,&bss);CHKERRQ(ierr);
84   ierr = VecGetArrayRead(ctx->xlocal,&array);CHKERRQ(ierr);
85   for (f=0;f<nf;f++) {
86     ierr = VecGetBlockSize((Vec)oXf[f],&bss[f]);CHKERRQ(ierr);
87     ierr = VecGetArray((Vec)oXf[f],&arrayf[f]);CHKERRQ(ierr);
88   }
89   for (ke = kst, ii = 0; ke < kst + ken; ke++) {
90     for (je = jst; je < jst + jen; je++) {
91       for (ie = ist; ie < ist + ien; ie++) {
92         PetscInt cf,b;
93         i = ke * gm * gn + je * gm + ie;
94         for (f=0,cf=0;f<nf;f++)
95           for (b=0;b<bss[f];b++)
96             arrayf[f][bss[f]*ii+b] = array[i*bs+cf++];
97         ii++;
98       }
99     }
100   }
101   for (f=0;f<nf;f++) { ierr = VecRestoreArray((Vec)oXf[f],&arrayf[f]);CHKERRQ(ierr); }
102   ierr = VecRestoreArrayRead(ctx->xlocal,&array);CHKERRQ(ierr);
103   ierr = PetscFree2(arrayf,bss);CHKERRQ(ierr);
104   PetscFunctionReturn(0);
105 }
106 
107 PETSC_INTERN PetscErrorCode DMSetUpGLVisViewer_DMDA(PetscObject oda, PetscViewer viewer)
108 {
109   DM                 da = (DM)oda,daview,dacoord;
110   Vec                xcoor,xcoorl,xlocal;
111   DMDAGLVisViewerCtx *ctx;
112   const char         **dafieldname;
113   char               **fec_type,**fieldname,fec[64];
114   const PetscInt     *lx,*ly,*lz;
115   PetscInt           *nlocal,*bss,*dims;
116   PetscInt           dim,M,N,P,m,n,p,dof,s,i,nf;
117   PetscBool          bsset;
118   PetscErrorCode     ierr;
119 
120   PetscFunctionBegin;
121   ierr = PetscObjectQuery(oda,"GLVisGraphicsCoordsGhosted",(PetscObject*)&xcoorl);CHKERRQ(ierr);
122   if (xcoorl) PetscFunctionReturn(0);
123   /* Create a properly ghosted DMDA to visualize the mesh and the fields associated with */
124   ierr = DMDAGetInfo(da,&dim,&M,&N,&P,&m,&n,&p,&dof,&s,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
125   ierr = DMDAGetOwnershipRanges(da,&lx,&ly,&lz);CHKERRQ(ierr);
126   ierr = DMGetCoordinates(da,&xcoor);CHKERRQ(ierr);
127   ierr = PetscInfo(da,"Creating auxilary DMDA for managing GLVis graphics\n");CHKERRQ(ierr);
128   switch (dim) {
129   case 1:
130     ierr = DMDACreate1d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,M,dof,1,lx,&daview);CHKERRQ(ierr);
131     ierr = DMDACreate1d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,M,1,1,lx,&dacoord);CHKERRQ(ierr);
132     ierr = PetscStrcpy(fec,"FiniteElementCollection: H1_1D_P1");CHKERRQ(ierr);
133     break;
134   case 2:
135     ierr = DMDACreate2d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,m,n,dof,1,lx,ly,&daview);CHKERRQ(ierr);
136     ierr = DMDACreate2d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,m,n,2,1,lx,ly,&dacoord);CHKERRQ(ierr);
137     ierr = PetscStrcpy(fec,"FiniteElementCollection: H1_2D_P1");CHKERRQ(ierr);
138     break;
139   case 3:
140     ierr = DMDACreate3d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,P,m,n,p,dof,1,lx,ly,lz,&daview);CHKERRQ(ierr);
141     ierr = DMDACreate3d(PetscObjectComm((PetscObject)da),DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,P,m,n,p,3,1,lx,ly,lz,&dacoord);CHKERRQ(ierr);
142     ierr = PetscStrcpy(fec,"FiniteElementCollection: H1_3D_P1");CHKERRQ(ierr);
143     break;
144   default:
145     SETERRQ1(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Unsupported dimension %D",dim);
146     break;
147   }
148   ierr = DMSetUp(daview);CHKERRQ(ierr);
149   ierr = DMSetUp(dacoord);CHKERRQ(ierr);
150   if (!xcoor) {
151     ierr = DMDASetUniformCoordinates(daview,0.0,1.0,0.0,1.0,0.0,1.0);CHKERRQ(ierr);
152     ierr = DMGetCoordinates(daview,&xcoor);CHKERRQ(ierr);
153   }
154   ierr = DMCreateLocalVector(daview,&xlocal);CHKERRQ(ierr);
155   ierr = DMCreateLocalVector(dacoord,&xcoorl);CHKERRQ(ierr);
156   ierr = DMGlobalToLocalBegin(dacoord,xcoor,INSERT_VALUES,xcoorl);CHKERRQ(ierr);
157   ierr = DMGlobalToLocalEnd(dacoord,xcoor,INSERT_VALUES,xcoorl);CHKERRQ(ierr);
158 
159   /* xcoorl is composed with the original DMDA, ghosted coordinate DMDA is only available through this vector */
160   ierr = PetscObjectCompose(oda,"GLVisGraphicsCoordsGhosted",(PetscObject)xcoorl);CHKERRQ(ierr);
161   ierr = PetscObjectDereference((PetscObject)xcoorl);CHKERRQ(ierr);
162 
163   /* customize the viewer */
164   ierr = DMDAGetFieldNames(da,(const char * const **)&dafieldname);CHKERRQ(ierr);
165   ierr = DMDAGetNumVerticesGhosted(daview,&M,&N,&P);CHKERRQ(ierr);
166   ierr = PetscMalloc5(dof,&fec_type,dof,&nlocal,dof,&bss,dof,&dims,dof,&fieldname);CHKERRQ(ierr);
167   for (i=0;i<dof;i++) bss[i] = 1;
168   nf = dof;
169 
170   ierr = PetscOptionsBegin(PetscObjectComm(oda),oda->prefix,"GLVis PetscViewer DMDA Options","PetscViewer");CHKERRQ(ierr);
171   ierr = PetscOptionsIntArray("-viewer_glvis_dm_da_bs","Block sizes for subfields; enable vector representation",NULL,bss,&nf,&bsset);CHKERRQ(ierr);
172   ierr = PetscOptionsEnd();CHKERRQ(ierr);
173   if (bsset) {
174     PetscInt t;
175     for (i=0,t=0;i<nf;i++) t += bss[i];
176     if (t != dof) SETERRQ2(PetscObjectComm(oda),PETSC_ERR_USER,"Sum of block sizes %D should equal %D",t,dof);
177   } else nf = dof;
178 
179   for (i=0,s=0;i<nf;i++) {
180     ierr = PetscStrallocpy(fec,&fec_type[i]);CHKERRQ(ierr);
181     if (bss[i] == 1) {
182       ierr = PetscStrallocpy(dafieldname[s],&fieldname[i]);CHKERRQ(ierr);
183     } else {
184       PetscInt b;
185       size_t tlen = 9; /* "Vector-" + end */
186       for (b=0;b<bss[i];b++) {
187         size_t len;
188         ierr = PetscStrlen(dafieldname[s+b],&len);CHKERRQ(ierr);
189         tlen += len + 1; /* field + "-" */
190       }
191       ierr = PetscMalloc1(tlen,&fieldname[i]);CHKERRQ(ierr);
192       ierr = PetscStrcpy(fieldname[i],"Vector-");CHKERRQ(ierr);
193       for (b=0;b<bss[i]-1;b++) {
194         ierr = PetscStrcat(fieldname[i],dafieldname[s+b]);CHKERRQ(ierr);
195         ierr = PetscStrcat(fieldname[i],"-");CHKERRQ(ierr);
196       }
197       ierr = PetscStrcat(fieldname[i],dafieldname[s+b]);CHKERRQ(ierr);
198     }
199     dims[i] = dim;
200     nlocal[i] = M*N*P*bss[i];
201     s += bss[i];
202   }
203 
204   /* the viewer context takes ownership of xlocal (and the the properly ghosted DMDA associated with it) */
205   ierr = PetscNew(&ctx);CHKERRQ(ierr);
206   ctx->xlocal = xlocal;
207 
208   ierr = PetscViewerGLVisSetFields(viewer,nf,(const char**)fieldname,(const char**)fec_type,nlocal,bss,dims,DMDASampleGLVisFields_Private,ctx,DMDADestroyGLVisViewerCtx_Private);CHKERRQ(ierr);
209   for (i=0;i<nf;i++) {
210     ierr = PetscFree(fec_type[i]);CHKERRQ(ierr);
211     ierr = PetscFree(fieldname[i]);CHKERRQ(ierr);
212   }
213   ierr = PetscFree5(fec_type,nlocal,bss,dims,fieldname);CHKERRQ(ierr);
214   ierr = DMDestroy(&dacoord);CHKERRQ(ierr);
215   ierr = DMDestroy(&daview);CHKERRQ(ierr);
216   PetscFunctionReturn(0);
217 }
218 
219 static PetscErrorCode DMDAView_GLVis_ASCII(DM dm, PetscViewer viewer)
220 {
221   DM                da;
222   Vec               xcoorl;
223   PetscMPIInt       commsize;
224   const PetscScalar *array;
225   PetscContainer    glvis_container;
226   PetscInt          dim,sdim,i,vid[8],mid,cid;
227   PetscInt          sx,sy,sz,ie,je,ke,ien,jen,ken;
228   PetscInt          gsx,gsy,gsz,gm,gn,gp,kst,jst,ist;
229   PetscBool         enabled = PETSC_TRUE, isascii;
230   PetscErrorCode    ierr;
231 
232   PetscFunctionBegin;
233   PetscValidHeaderSpecific(dm,DM_CLASSID,1);
234   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,2);
235   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);CHKERRQ(ierr);
236   if (!isascii) SETERRQ(PetscObjectComm((PetscObject)viewer),PETSC_ERR_SUP,"Viewer must be of type VIEWERASCII");
237   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)viewer),&commsize);CHKERRQ(ierr);
238   if (commsize > 1) SETERRQ(PetscObjectComm((PetscObject)viewer),PETSC_ERR_SUP,"Use single sequential viewers for parallel visualization");
239   ierr = DMGetDimension(dm,&dim);CHKERRQ(ierr);
240 
241   /* get container: determines if a process visualizes is portion of the data or not */
242   ierr = PetscObjectQuery((PetscObject)viewer,"_glvis_info_container",(PetscObject*)&glvis_container);CHKERRQ(ierr);
243   if (!glvis_container) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_PLIB,"Missing GLVis container");
244   {
245     PetscViewerGLVisInfo glvis_info;
246     ierr = PetscContainerGetPointer(glvis_container,(void**)&glvis_info);CHKERRQ(ierr);
247     enabled = glvis_info->enabled;
248   }
249   ierr = PetscObjectQuery((PetscObject)dm,"GLVisGraphicsCoordsGhosted",(PetscObject*)&xcoorl);CHKERRQ(ierr);
250   if (!xcoorl) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_PLIB,"Missing GLVis ghosted coords");
251   ierr = VecGetDM(xcoorl,&da);CHKERRQ(ierr);
252   if (!da) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_PLIB,"Missing GLVis ghosted DMDA");
253   ierr = DMGetCoordinateDim(da,&sdim);CHKERRQ(ierr);
254 
255   ierr = PetscViewerASCIIPrintf(viewer,"MFEM mesh v1.1\n");CHKERRQ(ierr);
256   ierr = PetscViewerASCIIPrintf(viewer,"\ndimension\n");CHKERRQ(ierr);
257   ierr = PetscViewerASCIIPrintf(viewer,"%D\n",dim);CHKERRQ(ierr);
258 
259   if (!enabled) {
260     ierr = PetscViewerASCIIPrintf(viewer,"\nelements\n");CHKERRQ(ierr);
261     ierr = PetscViewerASCIIPrintf(viewer,"%D\n",0);CHKERRQ(ierr);
262     ierr = PetscViewerASCIIPrintf(viewer,"\nboundary\n");CHKERRQ(ierr);
263     ierr = PetscViewerASCIIPrintf(viewer,"%D\n",0);CHKERRQ(ierr);
264     ierr = PetscViewerASCIIPrintf(viewer,"\nvertices\n");CHKERRQ(ierr);
265     ierr = PetscViewerASCIIPrintf(viewer,"%D\n",0);CHKERRQ(ierr);
266     ierr = PetscViewerASCIIPrintf(viewer,"%D\n",sdim);CHKERRQ(ierr);
267     PetscFunctionReturn(0);
268   }
269 
270   ierr = DMDAGetNumElementsGhosted(da,&ien,&jen,&ken);CHKERRQ(ierr);
271   i    = ien;
272   if (dim > 1) i *= jen;
273   if (dim > 2) i *= ken;
274   ierr = PetscViewerASCIIPrintf(viewer,"\nelements\n");CHKERRQ(ierr);
275   ierr = PetscViewerASCIIPrintf(viewer,"%D\n",i);CHKERRQ(ierr);
276   switch (dim) {
277   case 1:
278     for (ie = 0; ie < ien; ie++) {
279       vid[0] = ie;
280       vid[1] = ie+1;
281       mid    = 1; /* material id */
282       cid    = 1; /* segment */
283       ierr   = PetscViewerASCIIPrintf(viewer,"%D %D %D %D\n",mid,cid,vid[0],vid[1]);CHKERRQ(ierr);
284     }
285     break;
286   case 2:
287     for (je = 0; je < jen; je++) {
288       for (ie = 0; ie < ien; ie++) {
289         vid[0] =     je*(ien+1) + ie;
290         vid[1] =     je*(ien+1) + ie+1;
291         vid[2] = (je+1)*(ien+1) + ie+1;
292         vid[3] = (je+1)*(ien+1) + ie;
293         mid    = 1; /* material id */
294         cid    = 3; /* quad */
295         ierr   = PetscViewerASCIIPrintf(viewer,"%D %D %D %D %D %D\n",mid,cid,vid[0],vid[1],vid[2],vid[3]);CHKERRQ(ierr);
296       }
297     }
298     break;
299   case 3:
300     for (ke = 0; ke < ken; ke++) {
301       for (je = 0; je < jen; je++) {
302         for (ie = 0; ie < ien; ie++) {
303           vid[0] =     ke*(jen+1)*(ien+1) +     je*(ien+1) + ie;
304           vid[1] =     ke*(jen+1)*(ien+1) +     je*(ien+1) + ie+1;
305           vid[2] =     ke*(jen+1)*(ien+1) + (je+1)*(ien+1) + ie+1;
306           vid[3] =     ke*(jen+1)*(ien+1) + (je+1)*(ien+1) + ie;
307           vid[4] = (ke+1)*(jen+1)*(ien+1) +     je*(ien+1) + ie;
308           vid[5] = (ke+1)*(jen+1)*(ien+1) +     je*(ien+1) + ie+1;
309           vid[6] = (ke+1)*(jen+1)*(ien+1) + (je+1)*(ien+1) + ie+1;
310           vid[7] = (ke+1)*(jen+1)*(ien+1) + (je+1)*(ien+1) + ie;
311           mid    = 1; /* material id */
312           cid    = 5; /* hex */
313           ierr   = PetscViewerASCIIPrintf(viewer,"%D %D %D %D %D %D %D %D %D %D\n",mid,cid,vid[0],vid[1],vid[2],vid[3],vid[4],vid[5],vid[6],vid[7]);CHKERRQ(ierr);
314         }
315       }
316     }
317     break;
318   default:
319     SETERRQ1(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Unsupported dimension %D",dim);
320     break;
321   }
322   ierr = PetscViewerASCIIPrintf(viewer,"\nboundary\n");CHKERRQ(ierr);
323   ierr = PetscViewerASCIIPrintf(viewer,"%D\n",0);CHKERRQ(ierr);
324 
325   ierr = DMDAGetNumVerticesGhosted(da,&ien,&jen,&ken);CHKERRQ(ierr);
326   ierr = DMDAGetCorners(da,&sx,&sy,&sz,NULL,NULL,NULL);CHKERRQ(ierr);
327   ierr = DMDAGetGhostCorners(da,&gsx,&gsy,&gsz,&gm,&gn,&gp);CHKERRQ(ierr);
328   kst  = gsz != sz ? 1 : 0;
329   jst  = gsy != sy ? 1 : 0;
330   ist  = gsx != sx ? 1 : 0;
331   ierr = PetscViewerASCIIPrintf(viewer,"\nvertices\n");CHKERRQ(ierr);
332   ierr = PetscViewerASCIIPrintf(viewer,"%D\n",ien*jen*ken);CHKERRQ(ierr);
333   ierr = PetscViewerASCIIPrintf(viewer,"%D\n",sdim);CHKERRQ(ierr);
334   ierr = VecGetArrayRead(xcoorl,&array);CHKERRQ(ierr);
335   for (ke = kst; ke < kst + ken; ke++) {
336     for (je = jst; je < jst + jen; je++) {
337       for (ie = ist; ie < ist + ien; ie++) {
338         PetscInt d;
339 
340         i = ke * gm * gn + je * gm + ie;
341         for (d=0;d<sdim-1;d++) {
342           ierr = PetscViewerASCIIPrintf(viewer,"%g ",PetscRealPart(array[sdim*i+d]));CHKERRQ(ierr);
343         }
344         ierr = PetscViewerASCIIPrintf(viewer,"%g\n",PetscRealPart(array[sdim*i+d]));CHKERRQ(ierr);
345       }
346     }
347   }
348   ierr = VecRestoreArrayRead(xcoorl,&array);CHKERRQ(ierr);
349   PetscFunctionReturn(0);
350 }
351 
352 /* dispatching, prints through the socket by prepending the mesh keyword to the usual ASCII dump: duplicated code as in plexglvis.c, should be merged together */
353 PETSC_INTERN PetscErrorCode DMView_DA_GLVis(DM dm, PetscViewer viewer)
354 {
355   PetscErrorCode ierr;
356   PetscBool      isglvis,isascii;
357 
358   PetscFunctionBegin;
359   PetscValidHeaderSpecific(dm,DM_CLASSID,1);
360   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
361   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERGLVIS,&isglvis);CHKERRQ(ierr);
362   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);CHKERRQ(ierr);
363   if (!isglvis && !isascii) SETERRQ(PetscObjectComm((PetscObject)viewer),PETSC_ERR_SUP,"Viewer must be of type VIEWERGLVIS or VIEWERASCII");
364   if (isglvis) {
365     PetscViewer          view;
366     PetscViewerGLVisType type;
367 
368     ierr = PetscViewerGLVisGetType_Private(viewer,&type);CHKERRQ(ierr);
369     ierr = PetscViewerGLVisGetDMWindow_Private(viewer,&view);CHKERRQ(ierr);
370     if (view) { /* in the socket case, it may happen that the connection failed */
371       if (type == PETSC_VIEWER_GLVIS_SOCKET) {
372         PetscMPIInt size,rank;
373         ierr = MPI_Comm_size(PetscObjectComm((PetscObject)dm),&size);CHKERRQ(ierr);
374         ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)dm),&rank);CHKERRQ(ierr);
375         ierr = PetscViewerASCIIPrintf(view,"parallel %D %D\nmesh\n",size,rank);CHKERRQ(ierr);
376       }
377       ierr = DMDAView_GLVis_ASCII(dm,view);CHKERRQ(ierr);
378       ierr = PetscViewerFlush(view);CHKERRQ(ierr);
379       if (type == PETSC_VIEWER_GLVIS_SOCKET) {
380         PetscInt    dim;
381         const char* name;
382 
383         ierr = PetscObjectGetName((PetscObject)dm,&name);CHKERRQ(ierr);
384         ierr = DMGetDimension(dm,&dim);CHKERRQ(ierr);
385         ierr = PetscViewerGLVisInitWindow_Private(view,PETSC_TRUE,dim,name);CHKERRQ(ierr);
386         ierr = PetscBarrier((PetscObject)dm);CHKERRQ(ierr);
387       }
388     }
389   } else {
390     ierr = DMDAView_GLVis_ASCII(dm,viewer);CHKERRQ(ierr);
391   }
392   PetscFunctionReturn(0);
393 }
394