xref: /petsc/src/dm/impls/da/gr2.c (revision af0996ce37bc06907c37d8d91773840993d61e62)
1 
2 /*
3    Plots vectors obtained with DMDACreate2d()
4 */
5 
6 #include <petsc/private/dmdaimpl.h>      /*I  "petscdmda.h"   I*/
7 #include <petsc/private/vecimpl.h>
8 #include <petscdraw.h>
9 #include <petscviewerhdf5.h>
10 
11 /*
12         The data that is passed into the graphics callback
13 */
14 typedef struct {
15   PetscInt          m,n,step,k;
16   PetscReal         min,max,scale;
17   const PetscScalar *xy,*v;
18   PetscBool         showgrid;
19   const char        *name0,*name1;
20 } ZoomCtx;
21 
22 /*
23        This does the drawing for one particular field
24     in one particular set of coordinates. It is a callback
25     called from PetscDrawZoom()
26 */
27 #undef __FUNCT__
28 #define __FUNCT__ "VecView_MPI_Draw_DA2d_Zoom"
29 PetscErrorCode VecView_MPI_Draw_DA2d_Zoom(PetscDraw draw,void *ctx)
30 {
31   ZoomCtx           *zctx = (ZoomCtx*)ctx;
32   PetscErrorCode    ierr;
33   PetscInt          m,n,i,j,k,step,id,c1,c2,c3,c4;
34   PetscReal         s,min,max,x1,x2,x3,x4,y_1,y2,y3,y4,xmin = PETSC_MAX_REAL,xmax = PETSC_MIN_REAL,ymin = PETSC_MAX_REAL,ymax = PETSC_MIN_REAL;
35   PetscReal         xminf,xmaxf,yminf,ymaxf,w;
36   const PetscScalar *v,*xy;
37   char              value[16];
38   size_t            len;
39 
40   PetscFunctionBegin;
41   m    = zctx->m;
42   n    = zctx->n;
43   step = zctx->step;
44   k    = zctx->k;
45   v    = zctx->v;
46   xy   = zctx->xy;
47   s    = zctx->scale;
48   min  = zctx->min;
49   max  = zctx->max;
50 
51   /* PetscDraw the contour plot patch */
52   for (j=0; j<n-1; j++) {
53     for (i=0; i<m-1; i++) {
54       id   = i+j*m;
55       x1   = PetscRealPart(xy[2*id]);
56       y_1  = PetscRealPart(xy[2*id+1]);
57       c1   = (int)(PETSC_DRAW_BASIC_COLORS+s*(PetscClipInterval(PetscRealPart(v[k+step*id]),min,max)-min));
58       xmin = PetscMin(xmin,x1);
59       ymin = PetscMin(ymin,y_1);
60       xmax = PetscMax(xmax,x1);
61       ymax = PetscMax(ymax,y_1);
62 
63       id   = i+j*m+1;
64       x2   = PetscRealPart(xy[2*id]);
65       y2   = PetscRealPart(xy[2*id+1]);
66       c2   = (int)(PETSC_DRAW_BASIC_COLORS+s*(PetscClipInterval(PetscRealPart(v[k+step*id]),min,max)-min));
67       xmin = PetscMin(xmin,x2);
68       ymin = PetscMin(ymin,y2);
69       xmax = PetscMax(xmax,x2);
70       ymax = PetscMax(ymax,y2);
71 
72       id   = i+j*m+1+m;
73       x3   = PetscRealPart(xy[2*id]);
74       y3   = PetscRealPart(xy[2*id+1]);
75       c3   = (int)(PETSC_DRAW_BASIC_COLORS+s*(PetscClipInterval(PetscRealPart(v[k+step*id]),min,max)-min));
76       xmin = PetscMin(xmin,x3);
77       ymin = PetscMin(ymin,y3);
78       xmax = PetscMax(xmax,x3);
79       ymax = PetscMax(ymax,y3);
80 
81       id = i+j*m+m;
82       x4 = PetscRealPart(xy[2*id]);
83       y4 = PetscRealPart(xy[2*id+1]);
84       c4 = (int)(PETSC_DRAW_BASIC_COLORS+s*(PetscClipInterval(PetscRealPart(v[k+step*id]),min,max)-min));
85       xmin = PetscMin(xmin,x4);
86       ymin = PetscMin(ymin,y4);
87       xmax = PetscMax(xmax,x4);
88       ymax = PetscMax(ymax,y4);
89 
90       ierr = PetscDrawTriangle(draw,x1,y_1,x2,y2,x3,y3,c1,c2,c3);CHKERRQ(ierr);
91       ierr = PetscDrawTriangle(draw,x1,y_1,x3,y3,x4,y4,c1,c3,c4);CHKERRQ(ierr);
92       if (zctx->showgrid) {
93         ierr = PetscDrawLine(draw,x1,y_1,x2,y2,PETSC_DRAW_BLACK);CHKERRQ(ierr);
94         ierr = PetscDrawLine(draw,x2,y2,x3,y3,PETSC_DRAW_BLACK);CHKERRQ(ierr);
95         ierr = PetscDrawLine(draw,x3,y3,x4,y4,PETSC_DRAW_BLACK);CHKERRQ(ierr);
96         ierr = PetscDrawLine(draw,x4,y4,x1,y_1,PETSC_DRAW_BLACK);CHKERRQ(ierr);
97       }
98     }
99   }
100   if (zctx->name0) {
101     PetscReal xl,yl,xr,yr,x,y;
102     ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr);
103     x    = xl + .3*(xr - xl);
104     xl   = xl + .01*(xr - xl);
105     y    = yr - .3*(yr - yl);
106     yl   = yl + .01*(yr - yl);
107     ierr = PetscDrawString(draw,x,yl,PETSC_DRAW_BLACK,zctx->name0);CHKERRQ(ierr);
108     ierr = PetscDrawStringVertical(draw,xl,y,PETSC_DRAW_BLACK,zctx->name1);CHKERRQ(ierr);
109   }
110   /*
111      Ideally we would use the PetscDrawAxis object to manage displaying the coordinate limits
112      but that may require some refactoring.
113   */
114   ierr = MPI_Allreduce(&xmin,&xminf,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)draw));CHKERRQ(ierr);
115   ierr = MPI_Allreduce(&xmax,&xmaxf,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)draw));CHKERRQ(ierr);
116   ierr = MPI_Allreduce(&ymin,&yminf,1,MPIU_REAL,MPIU_MIN,PetscObjectComm((PetscObject)draw));CHKERRQ(ierr);
117   ierr = MPI_Allreduce(&ymax,&ymaxf,1,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)draw));CHKERRQ(ierr);
118   ierr = PetscSNPrintf(value,16,"%f",xminf);CHKERRQ(ierr);
119   ierr = PetscDrawString(draw,xminf,yminf - .05*(ymaxf - yminf),PETSC_DRAW_BLACK,value);CHKERRQ(ierr);
120   ierr = PetscSNPrintf(value,16,"%f",xmaxf);CHKERRQ(ierr);
121   ierr = PetscStrlen(value,&len);CHKERRQ(ierr);
122   ierr = PetscDrawStringGetSize(draw,&w,NULL);CHKERRQ(ierr);
123   ierr = PetscDrawString(draw,xmaxf - len*w,yminf - .05*(ymaxf - yminf),PETSC_DRAW_BLACK,value);CHKERRQ(ierr);
124   ierr = PetscSNPrintf(value,16,"%f",yminf);CHKERRQ(ierr);
125   ierr = PetscDrawString(draw,xminf - .05*(xmaxf - xminf),yminf,PETSC_DRAW_BLACK,value);CHKERRQ(ierr);
126   ierr = PetscSNPrintf(value,16,"%f",ymaxf);CHKERRQ(ierr);
127   ierr = PetscDrawString(draw,xminf - .05*(xmaxf - xminf),ymaxf,PETSC_DRAW_BLACK,value);CHKERRQ(ierr);
128   PetscFunctionReturn(0);
129 }
130 
131 #undef __FUNCT__
132 #define __FUNCT__ "VecView_MPI_Draw_DA2d"
133 PetscErrorCode VecView_MPI_Draw_DA2d(Vec xin,PetscViewer viewer)
134 {
135   DM                 da,dac,dag;
136   PetscErrorCode     ierr;
137   PetscMPIInt        rank;
138   PetscInt           N,s,M,w,ncoors = 4;
139   const PetscInt     *lx,*ly;
140   PetscReal          coors[4],ymin,ymax,xmin,xmax;
141   PetscDraw          draw,popup;
142   PetscBool          isnull,useports = PETSC_FALSE;
143   MPI_Comm           comm;
144   Vec                xlocal,xcoor,xcoorl;
145   DMBoundaryType     bx,by;
146   DMDAStencilType    st;
147   ZoomCtx            zctx;
148   PetscDrawViewPorts *ports = NULL;
149   PetscViewerFormat  format;
150   PetscInt           *displayfields;
151   PetscInt           ndisplayfields,i,nbounds;
152   const PetscReal    *bounds;
153 
154   PetscFunctionBegin;
155   zctx.showgrid = PETSC_FALSE;
156 
157   ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
158   ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); if (isnull) PetscFunctionReturn(0);
159   ierr = PetscViewerDrawGetBounds(viewer,&nbounds,&bounds);CHKERRQ(ierr);
160 
161   ierr = VecGetDM(xin,&da);CHKERRQ(ierr);
162   if (!da) SETERRQ(PetscObjectComm((PetscObject)xin),PETSC_ERR_ARG_WRONG,"Vector not generated from a DMDA");
163 
164   ierr = PetscObjectGetComm((PetscObject)xin,&comm);CHKERRQ(ierr);
165   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
166 
167   ierr = DMDAGetInfo(da,0,&M,&N,0,&zctx.m,&zctx.n,0,&w,&s,&bx,&by,0,&st);CHKERRQ(ierr);
168   ierr = DMDAGetOwnershipRanges(da,&lx,&ly,NULL);CHKERRQ(ierr);
169 
170   /*
171         Obtain a sequential vector that is going to contain the local values plus ONE layer of
172      ghosted values to draw the graphics from. We also need its corresponding DMDA (dac) that will
173      update the local values pluse ONE layer of ghost values.
174   */
175   ierr = PetscObjectQuery((PetscObject)da,"GraphicsGhosted",(PetscObject*)&xlocal);CHKERRQ(ierr);
176   if (!xlocal) {
177     if (bx !=  DM_BOUNDARY_NONE || by !=  DM_BOUNDARY_NONE || s != 1 || st != DMDA_STENCIL_BOX) {
178       /*
179          if original da is not of stencil width one, or periodic or not a box stencil then
180          create a special DMDA to handle one level of ghost points for graphics
181       */
182       ierr = DMDACreate2d(comm,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,zctx.m,zctx.n,w,1,lx,ly,&dac);CHKERRQ(ierr);
183       ierr = PetscInfo(da,"Creating auxilary DMDA for managing graphics ghost points\n");CHKERRQ(ierr);
184     } else {
185       /* otherwise we can use the da we already have */
186       dac = da;
187     }
188     /* create local vector for holding ghosted values used in graphics */
189     ierr = DMCreateLocalVector(dac,&xlocal);CHKERRQ(ierr);
190     if (dac != da) {
191       /* don't keep any public reference of this DMDA, is is only available through xlocal */
192       ierr = PetscObjectDereference((PetscObject)dac);CHKERRQ(ierr);
193     } else {
194       /* remove association between xlocal and da, because below we compose in the opposite
195          direction and if we left this connect we'd get a loop, so the objects could
196          never be destroyed */
197       ierr = PetscObjectRemoveReference((PetscObject)xlocal,"__PETSc_dm");CHKERRQ(ierr);
198     }
199     ierr = PetscObjectCompose((PetscObject)da,"GraphicsGhosted",(PetscObject)xlocal);CHKERRQ(ierr);
200     ierr = PetscObjectDereference((PetscObject)xlocal);CHKERRQ(ierr);
201   } else {
202     if (bx !=  DM_BOUNDARY_NONE || by !=  DM_BOUNDARY_NONE || s != 1 || st != DMDA_STENCIL_BOX) {
203       ierr = VecGetDM(xlocal, &dac);CHKERRQ(ierr);
204     } else {
205       dac = da;
206     }
207   }
208 
209   /*
210       Get local (ghosted) values of vector
211   */
212   ierr = DMGlobalToLocalBegin(dac,xin,INSERT_VALUES,xlocal);CHKERRQ(ierr);
213   ierr = DMGlobalToLocalEnd(dac,xin,INSERT_VALUES,xlocal);CHKERRQ(ierr);
214   ierr = VecGetArrayRead(xlocal,&zctx.v);CHKERRQ(ierr);
215 
216   /* get coordinates of nodes */
217   ierr = DMGetCoordinates(da,&xcoor);CHKERRQ(ierr);
218   if (!xcoor) {
219     ierr = DMDASetUniformCoordinates(da,0.0,1.0,0.0,1.0,0.0,0.0);CHKERRQ(ierr);
220     ierr = DMGetCoordinates(da,&xcoor);CHKERRQ(ierr);
221   }
222 
223   /*
224       Determine the min and max  coordinates in plot
225   */
226   ierr     = VecStrideMin(xcoor,0,NULL,&xmin);CHKERRQ(ierr);
227   ierr     = VecStrideMax(xcoor,0,NULL,&xmax);CHKERRQ(ierr);
228   ierr     = VecStrideMin(xcoor,1,NULL,&ymin);CHKERRQ(ierr);
229   ierr     = VecStrideMax(xcoor,1,NULL,&ymax);CHKERRQ(ierr);
230   coors[0] = xmin - .05*(xmax- xmin); coors[2] = xmax + .05*(xmax - xmin);
231   coors[1] = ymin - .05*(ymax- ymin); coors[3] = ymax + .05*(ymax - ymin);
232   ierr     = PetscInfo4(da,"Preparing DMDA 2d contour plot coordinates %g %g %g %g\n",(double)coors[0],(double)coors[1],(double)coors[2],(double)coors[3]);CHKERRQ(ierr);
233 
234   ierr = PetscOptionsGetRealArray(NULL,"-draw_coordinates",coors,&ncoors,NULL);CHKERRQ(ierr);
235 
236   /*
237        get local ghosted version of coordinates
238   */
239   ierr = PetscObjectQuery((PetscObject)da,"GraphicsCoordinateGhosted",(PetscObject*)&xcoorl);CHKERRQ(ierr);
240   if (!xcoorl) {
241     /* create DMDA to get local version of graphics */
242     ierr = DMDACreate2d(comm,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,M,N,zctx.m,zctx.n,2,1,lx,ly,&dag);CHKERRQ(ierr);
243     ierr = PetscInfo(dag,"Creating auxilary DMDA for managing graphics coordinates ghost points\n");CHKERRQ(ierr);
244     ierr = DMCreateLocalVector(dag,&xcoorl);CHKERRQ(ierr);
245     ierr = PetscObjectCompose((PetscObject)da,"GraphicsCoordinateGhosted",(PetscObject)xcoorl);CHKERRQ(ierr);
246     ierr = PetscObjectDereference((PetscObject)dag);CHKERRQ(ierr);
247     ierr = PetscObjectDereference((PetscObject)xcoorl);CHKERRQ(ierr);
248   } else {
249     ierr = VecGetDM(xcoorl,&dag);CHKERRQ(ierr);
250   }
251   ierr = DMGlobalToLocalBegin(dag,xcoor,INSERT_VALUES,xcoorl);CHKERRQ(ierr);
252   ierr = DMGlobalToLocalEnd(dag,xcoor,INSERT_VALUES,xcoorl);CHKERRQ(ierr);
253   ierr = VecGetArrayRead(xcoorl,&zctx.xy);CHKERRQ(ierr);
254 
255   /*
256         Get information about size of area each processor must do graphics for
257   */
258   ierr = DMDAGetInfo(dac,0,&M,&N,0,0,0,0,&zctx.step,0,&bx,&by,0,0);CHKERRQ(ierr);
259   ierr = DMDAGetGhostCorners(dac,0,0,0,&zctx.m,&zctx.n,0);CHKERRQ(ierr);
260 
261   ierr = PetscOptionsGetBool(NULL,"-draw_contour_grid",&zctx.showgrid,NULL);CHKERRQ(ierr);
262 
263   ierr = DMDASelectFields(da,&ndisplayfields,&displayfields);CHKERRQ(ierr);
264 
265   ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
266   ierr = PetscOptionsGetBool(NULL,"-draw_ports",&useports,NULL);CHKERRQ(ierr);
267   if (useports || format == PETSC_VIEWER_DRAW_PORTS) {
268     ierr       = PetscDrawSynchronizedClear(draw);CHKERRQ(ierr);
269     ierr       = PetscDrawViewPortsCreate(draw,ndisplayfields,&ports);CHKERRQ(ierr);
270     zctx.name0 = 0;
271     zctx.name1 = 0;
272   } else {
273     ierr = DMDAGetCoordinateName(da,0,&zctx.name0);CHKERRQ(ierr);
274     ierr = DMDAGetCoordinateName(da,1,&zctx.name1);CHKERRQ(ierr);
275   }
276 
277   /*
278      Loop over each field; drawing each in a different window
279   */
280   for (i=0; i<ndisplayfields; i++) {
281     zctx.k = displayfields[i];
282     if (useports) {
283       ierr = PetscDrawViewPortsSet(ports,i);CHKERRQ(ierr);
284     } else {
285       ierr = PetscViewerDrawGetDraw(viewer,i,&draw);CHKERRQ(ierr);
286     }
287 
288     /*
289         Determine the min and max color in plot
290     */
291     ierr = VecStrideMin(xin,zctx.k,NULL,&zctx.min);CHKERRQ(ierr);
292     ierr = VecStrideMax(xin,zctx.k,NULL,&zctx.max);CHKERRQ(ierr);
293     if (zctx.k < nbounds) {
294       zctx.min = bounds[2*zctx.k];
295       zctx.max = bounds[2*zctx.k+1];
296     }
297     if (zctx.min == zctx.max) {
298       zctx.min -= 1.e-12;
299       zctx.max += 1.e-12;
300     }
301 
302     if (!rank) {
303       const char *title;
304 
305       ierr = DMDAGetFieldName(da,zctx.k,&title);CHKERRQ(ierr);
306       if (title) {
307         ierr = PetscDrawSetTitle(draw,title);CHKERRQ(ierr);
308       }
309     }
310     ierr = PetscDrawSetCoordinates(draw,coors[0],coors[1],coors[2],coors[3]);CHKERRQ(ierr);
311     ierr = PetscInfo2(da,"DMDA 2d contour plot min %g max %g\n",(double)zctx.min,(double)zctx.max);CHKERRQ(ierr);
312 
313     ierr = PetscDrawGetPopup(draw,&popup);CHKERRQ(ierr);
314     if (popup) {ierr = PetscDrawScalePopup(popup,zctx.min,zctx.max);CHKERRQ(ierr);}
315 
316     zctx.scale = (245.0 - PETSC_DRAW_BASIC_COLORS)/(zctx.max - zctx.min);
317 
318     ierr = PetscDrawZoom(draw,VecView_MPI_Draw_DA2d_Zoom,&zctx);CHKERRQ(ierr);
319   }
320   ierr = PetscFree(displayfields);CHKERRQ(ierr);
321   ierr = PetscDrawViewPortsDestroy(ports);CHKERRQ(ierr);
322 
323   ierr = VecRestoreArrayRead(xcoorl,&zctx.xy);CHKERRQ(ierr);
324   ierr = VecRestoreArrayRead(xlocal,&zctx.v);CHKERRQ(ierr);
325   PetscFunctionReturn(0);
326 }
327 
328 #if defined(PETSC_HAVE_HDF5)
329 #undef __FUNCT__
330 #define __FUNCT__ "VecGetHDF5ChunkSize"
331 static PetscErrorCode VecGetHDF5ChunkSize(DM_DA *da, Vec xin, PetscInt dimension, PetscInt timestep, hsize_t *chunkDims)
332 {
333   PetscMPIInt    comm_size;
334   PetscErrorCode ierr;
335   hsize_t        chunk_size, target_size, dim;
336   hsize_t        vec_size = sizeof(PetscScalar)*da->M*da->N*da->P*da->w;
337   hsize_t        avg_local_vec_size,KiB = 1024,MiB = KiB*KiB,GiB = MiB*KiB,min_size = MiB;
338   hsize_t        max_chunks = 64*KiB;                                              /* HDF5 internal limitation */
339   hsize_t        max_chunk_size = 4*GiB;                                           /* HDF5 internal limitation */
340   PetscInt       zslices=da->p, yslices=da->n, xslices=da->m;
341 
342   PetscFunctionBegin;
343   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)xin), &comm_size);CHKERRQ(ierr);
344   avg_local_vec_size = (hsize_t) ceil(vec_size*1.0/comm_size);      /* we will attempt to use this as the chunk size */
345 
346   target_size = (hsize_t) ceil(PetscMin(vec_size,PetscMin(max_chunk_size,PetscMax(avg_local_vec_size,PetscMax(ceil(vec_size*1.0/max_chunks),min_size)))));
347   /* following line uses sizeof(PetscReal) instead of sizeof(PetscScalar) because the last dimension of chunkDims[] captures the 2* when complex numbers are being used */
348   chunk_size = (hsize_t) PetscMax(1,chunkDims[0])*PetscMax(1,chunkDims[1])*PetscMax(1,chunkDims[2])*PetscMax(1,chunkDims[3])*PetscMax(1,chunkDims[4])*PetscMax(1,chunkDims[5])*sizeof(PetscReal);
349 
350   /*
351    if size/rank > max_chunk_size, we need radical measures: even going down to
352    avg_local_vec_size is not enough, so we simply use chunk size of 4 GiB no matter
353    what, composed in the most efficient way possible.
354    N.B. this minimises the number of chunks, which may or may not be the optimal
355    solution. In a BG, for example, the optimal solution is probably to make # chunks = #
356    IO nodes involved, but this author has no access to a BG to figure out how to
357    reliably find the right number. And even then it may or may not be enough.
358    */
359   if (avg_local_vec_size > max_chunk_size) {
360     /* check if we can just split local z-axis: is that enough? */
361     zslices = (PetscInt)ceil(vec_size*1.0/(da->p*max_chunk_size))*zslices;
362     if (zslices > da->P) {
363       /* lattice is too large in xy-directions, splitting z only is not enough */
364       zslices = da->P;
365       yslices= (PetscInt)ceil(vec_size*1.0/(zslices*da->n*max_chunk_size))*yslices;
366       if (yslices > da->N) {
367 	/* lattice is too large in x-direction, splitting along z, y is not enough */
368 	yslices = da->N;
369 	xslices= (PetscInt)ceil(vec_size*1.0/(zslices*yslices*da->m*max_chunk_size))*xslices;
370       }
371     }
372     dim = 0;
373     if (timestep >= 0) {
374       ++dim;
375     }
376     /* prefer to split z-axis, even down to planar slices */
377     if (dimension == 3) {
378       chunkDims[dim++] = (hsize_t) da->P/zslices;
379       chunkDims[dim++] = (hsize_t) da->N/yslices;
380       chunkDims[dim++] = (hsize_t) da->M/xslices;
381     } else {
382       /* This is a 2D world exceeding 4GiB in size; yes, I've seen them, even used myself */
383       chunkDims[dim++] = (hsize_t) da->N/yslices;
384       chunkDims[dim++] = (hsize_t) da->M/xslices;
385     }
386     chunk_size = (hsize_t) PetscMax(1,chunkDims[0])*PetscMax(1,chunkDims[1])*PetscMax(1,chunkDims[2])*PetscMax(1,chunkDims[3])*PetscMax(1,chunkDims[4])*PetscMax(1,chunkDims[5])*sizeof(double);
387   } else {
388     if (target_size < chunk_size) {
389       /* only change the defaults if target_size < chunk_size */
390       dim = 0;
391       if (timestep >= 0) {
392 	++dim;
393       }
394       /* prefer to split z-axis, even down to planar slices */
395       if (dimension == 3) {
396 	/* try splitting the z-axis to core-size bits, i.e. divide chunk size by # comm_size in z-direction */
397 	if (target_size >= chunk_size/da->p) {
398 	  /* just make chunks the size of <local_z>x<whole_world_y>x<whole_world_x>x<dof> */
399 	  chunkDims[dim] = (hsize_t) ceil(da->P*1.0/da->p);
400 	} else {
401 	  /* oops, just splitting the z-axis is NOT ENOUGH, need to split more; let's be
402            radical and let everyone write all they've got */
403 	  chunkDims[dim++] = (hsize_t) ceil(da->P*1.0/da->p);
404 	  chunkDims[dim++] = (hsize_t) ceil(da->N*1.0/da->n);
405 	  chunkDims[dim++] = (hsize_t) ceil(da->M*1.0/da->m);
406 	}
407       } else {
408 	/* This is a 2D world exceeding 4GiB in size; yes, I've seen them, even used myself */
409 	if (target_size >= chunk_size/da->n) {
410 	  /* just make chunks the size of <local_z>x<whole_world_y>x<whole_world_x>x<dof> */
411 	  chunkDims[dim] = (hsize_t) ceil(da->N*1.0/da->n);
412 	} else {
413 	  /* oops, just splitting the z-axis is NOT ENOUGH, need to split more; let's be
414 	   radical and let everyone write all they've got */
415 	  chunkDims[dim++] = (hsize_t) ceil(da->N*1.0/da->n);
416 	  chunkDims[dim++] = (hsize_t) ceil(da->M*1.0/da->m);
417 	}
418 
419       }
420       chunk_size = (hsize_t) PetscMax(1,chunkDims[0])*PetscMax(1,chunkDims[1])*PetscMax(1,chunkDims[2])*PetscMax(1,chunkDims[3])*PetscMax(1,chunkDims[4])*PetscMax(1,chunkDims[5])*sizeof(double);
421     } else {
422       /* precomputed chunks are fine, we don't need to do anything */
423     }
424   }
425   PetscFunctionReturn(0);
426 }
427 #endif
428 
429 #if defined(PETSC_HAVE_HDF5)
430 #undef __FUNCT__
431 #define __FUNCT__ "VecView_MPI_HDF5_DA"
432 PetscErrorCode VecView_MPI_HDF5_DA(Vec xin,PetscViewer viewer)
433 {
434   DM                dm;
435   DM_DA             *da;
436   hid_t             filespace;  /* file dataspace identifier */
437   hid_t             chunkspace; /* chunk dataset property identifier */
438   hid_t             plist_id;   /* property list identifier */
439   hid_t             dset_id;    /* dataset identifier */
440   hid_t             memspace;   /* memory dataspace identifier */
441   hid_t             file_id;
442   hid_t             group;
443   hid_t             scalartype; /* scalar type (H5T_NATIVE_FLOAT or H5T_NATIVE_DOUBLE) */
444   hsize_t           dim;
445   hsize_t           maxDims[6]={0}, dims[6]={0}, chunkDims[6]={0}, count[6]={0}, offset[6]={0}; /* we depend on these being sane later on  */
446   PetscInt          timestep, dimension;
447   const PetscScalar *x;
448   const char        *vecname;
449   PetscErrorCode    ierr;
450   PetscBool         dim2;
451 
452   PetscFunctionBegin;
453   ierr = PetscViewerHDF5OpenGroup(viewer, &file_id, &group);CHKERRQ(ierr);
454   ierr = PetscViewerHDF5GetTimestep(viewer, &timestep);CHKERRQ(ierr);
455   ierr = PetscViewerHDF5GetBaseDimension2(viewer,&dim2);CHKERRQ(ierr);
456 
457   ierr = VecGetDM(xin,&dm);CHKERRQ(ierr);
458   if (!dm) SETERRQ(PetscObjectComm((PetscObject)xin),PETSC_ERR_ARG_WRONG,"Vector not generated from a DMDA");
459   da = (DM_DA*)dm->data;
460   ierr = DMGetDimension(dm, &dimension);CHKERRQ(ierr);
461 
462   /* Create the dataspace for the dataset.
463    *
464    * dims - holds the current dimensions of the dataset
465    *
466    * maxDims - holds the maximum dimensions of the dataset (unlimited
467    * for the number of time steps with the current dimensions for the
468    * other dimensions; so only additional time steps can be added).
469    *
470    * chunkDims - holds the size of a single time step (required to
471    * permit extending dataset).
472    */
473   dim = 0;
474   if (timestep >= 0) {
475     dims[dim]      = timestep+1;
476     maxDims[dim]   = H5S_UNLIMITED;
477     chunkDims[dim] = 1;
478     ++dim;
479   }
480   if (dimension == 3) {
481     ierr           = PetscHDF5IntCast(da->P,dims+dim);CHKERRQ(ierr);
482     maxDims[dim]   = dims[dim];
483     chunkDims[dim] = dims[dim];
484     ++dim;
485   }
486   if (dimension > 1) {
487     ierr           = PetscHDF5IntCast(da->N,dims+dim);CHKERRQ(ierr);
488     maxDims[dim]   = dims[dim];
489     chunkDims[dim] = dims[dim];
490     ++dim;
491   }
492   ierr           = PetscHDF5IntCast(da->M,dims+dim);CHKERRQ(ierr);
493   maxDims[dim]   = dims[dim];
494   chunkDims[dim] = dims[dim];
495   ++dim;
496   if (da->w > 1 || dim2) {
497     ierr           = PetscHDF5IntCast(da->w,dims+dim);CHKERRQ(ierr);
498     maxDims[dim]   = dims[dim];
499     chunkDims[dim] = dims[dim];
500     ++dim;
501   }
502 #if defined(PETSC_USE_COMPLEX)
503   dims[dim]      = 2;
504   maxDims[dim]   = dims[dim];
505   chunkDims[dim] = dims[dim];
506   ++dim;
507 #endif
508 
509   ierr = VecGetHDF5ChunkSize(da, xin, dimension, timestep, chunkDims); CHKERRQ(ierr);
510 
511   PetscStackCallHDF5Return(filespace,H5Screate_simple,(dim, dims, maxDims));
512 
513 #if defined(PETSC_USE_REAL_SINGLE)
514   scalartype = H5T_NATIVE_FLOAT;
515 #elif defined(PETSC_USE_REAL___FLOAT128)
516 #error "HDF5 output with 128 bit floats not supported."
517 #else
518   scalartype = H5T_NATIVE_DOUBLE;
519 #endif
520 
521   /* Create the dataset with default properties and close filespace */
522   ierr = PetscObjectGetName((PetscObject)xin,&vecname);CHKERRQ(ierr);
523   if (!H5Lexists(group, vecname, H5P_DEFAULT)) {
524     /* Create chunk */
525     PetscStackCallHDF5Return(chunkspace,H5Pcreate,(H5P_DATASET_CREATE));
526     PetscStackCallHDF5(H5Pset_chunk,(chunkspace, dim, chunkDims));
527 
528 #if (H5_VERS_MAJOR * 10000 + H5_VERS_MINOR * 100 + H5_VERS_RELEASE >= 10800)
529     PetscStackCallHDF5Return(dset_id,H5Dcreate2,(group, vecname, scalartype, filespace, H5P_DEFAULT, chunkspace, H5P_DEFAULT));
530 #else
531     PetscStackCallHDF5Return(dset_id,H5Dcreate,(group, vecname, scalartype, filespace, H5P_DEFAULT));
532 #endif
533   } else {
534     PetscStackCallHDF5Return(dset_id,H5Dopen2,(group, vecname, H5P_DEFAULT));
535     PetscStackCallHDF5(H5Dset_extent,(dset_id, dims));
536   }
537   PetscStackCallHDF5(H5Sclose,(filespace));
538 
539   /* Each process defines a dataset and writes it to the hyperslab in the file */
540   dim = 0;
541   if (timestep >= 0) {
542     offset[dim] = timestep;
543     ++dim;
544   }
545   if (dimension == 3) {ierr = PetscHDF5IntCast(da->zs,offset + dim++);CHKERRQ(ierr);}
546   if (dimension > 1)  {ierr = PetscHDF5IntCast(da->ys,offset + dim++);CHKERRQ(ierr);}
547   ierr = PetscHDF5IntCast(da->xs/da->w,offset + dim++);CHKERRQ(ierr);
548   if (da->w > 1 || dim2) offset[dim++] = 0;
549 #if defined(PETSC_USE_COMPLEX)
550   offset[dim++] = 0;
551 #endif
552   dim = 0;
553   if (timestep >= 0) {
554     count[dim] = 1;
555     ++dim;
556   }
557   if (dimension == 3) {ierr = PetscHDF5IntCast(da->ze - da->zs,count + dim++);CHKERRQ(ierr);}
558   if (dimension > 1)  {ierr = PetscHDF5IntCast(da->ye - da->ys,count + dim++);CHKERRQ(ierr);}
559   ierr = PetscHDF5IntCast((da->xe - da->xs)/da->w,count + dim++);CHKERRQ(ierr);
560   if (da->w > 1 || dim2) {ierr = PetscHDF5IntCast(da->w,count + dim++);CHKERRQ(ierr);}
561 #if defined(PETSC_USE_COMPLEX)
562   count[dim++] = 2;
563 #endif
564   PetscStackCallHDF5Return(memspace,H5Screate_simple,(dim, count, NULL));
565   PetscStackCallHDF5Return(filespace,H5Dget_space,(dset_id));
566   PetscStackCallHDF5(H5Sselect_hyperslab,(filespace, H5S_SELECT_SET, offset, NULL, count, NULL));
567 
568   /* Create property list for collective dataset write */
569   PetscStackCallHDF5Return(plist_id,H5Pcreate,(H5P_DATASET_XFER));
570 #if defined(PETSC_HAVE_H5PSET_FAPL_MPIO)
571   PetscStackCallHDF5(H5Pset_dxpl_mpio,(plist_id, H5FD_MPIO_COLLECTIVE));
572 #endif
573   /* To write dataset independently use H5Pset_dxpl_mpio(plist_id, H5FD_MPIO_INDEPENDENT) */
574 
575   ierr   = VecGetArrayRead(xin, &x);CHKERRQ(ierr);
576   PetscStackCallHDF5(H5Dwrite,(dset_id, scalartype, memspace, filespace, plist_id, x));
577   PetscStackCallHDF5(H5Fflush,(file_id, H5F_SCOPE_GLOBAL));
578   ierr   = VecRestoreArrayRead(xin, &x);CHKERRQ(ierr);
579 
580   /* Close/release resources */
581   if (group != file_id) {
582     PetscStackCallHDF5(H5Gclose,(group));
583   }
584   PetscStackCallHDF5(H5Pclose,(plist_id));
585   PetscStackCallHDF5(H5Sclose,(filespace));
586   PetscStackCallHDF5(H5Sclose,(memspace));
587   PetscStackCallHDF5(H5Dclose,(dset_id));
588   ierr   = PetscInfo1(xin,"Wrote Vec object with name %s\n",vecname);CHKERRQ(ierr);
589   PetscFunctionReturn(0);
590 }
591 #endif
592 
593 extern PetscErrorCode VecView_MPI_Draw_DA1d(Vec,PetscViewer);
594 
595 #if defined(PETSC_HAVE_MPIIO)
596 #undef __FUNCT__
597 #define __FUNCT__ "DMDAArrayMPIIO"
598 static PetscErrorCode DMDAArrayMPIIO(DM da,PetscViewer viewer,Vec xin,PetscBool write)
599 {
600   PetscErrorCode    ierr;
601   MPI_File          mfdes;
602   PetscMPIInt       gsizes[4],lsizes[4],lstarts[4],asiz,dof;
603   MPI_Datatype      view;
604   const PetscScalar *array;
605   MPI_Offset        off;
606   MPI_Aint          ub,ul;
607   PetscInt          type,rows,vecrows,tr[2];
608   DM_DA             *dd = (DM_DA*)da->data;
609   PetscBool         skipheader;
610 
611   PetscFunctionBegin;
612   ierr = VecGetSize(xin,&vecrows);CHKERRQ(ierr);
613   ierr = PetscViewerBinaryGetSkipHeader(viewer,&skipheader);CHKERRQ(ierr);
614   if (!write) {
615     /* Read vector header. */
616     if (!skipheader) {
617       ierr = PetscViewerBinaryRead(viewer,tr,2,NULL,PETSC_INT);CHKERRQ(ierr);
618       type = tr[0];
619       rows = tr[1];
620       if (type != VEC_FILE_CLASSID) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_WRONG,"Not vector next in file");
621       if (rows != vecrows) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_SIZ,"Vector in file not same size as DMDA vector");
622     }
623   } else {
624     tr[0] = VEC_FILE_CLASSID;
625     tr[1] = vecrows;
626     if (!skipheader) {
627       ierr  = PetscViewerBinaryWrite(viewer,tr,2,PETSC_INT,PETSC_TRUE);CHKERRQ(ierr);
628     }
629   }
630 
631   ierr       = PetscMPIIntCast(dd->w,&dof);CHKERRQ(ierr);
632   gsizes[0]  = dof;
633   ierr       = PetscMPIIntCast(dd->M,gsizes+1);CHKERRQ(ierr);
634   ierr       = PetscMPIIntCast(dd->N,gsizes+2);CHKERRQ(ierr);
635   ierr       = PetscMPIIntCast(dd->P,gsizes+3);CHKERRQ(ierr);
636   lsizes[0]  = dof;
637   ierr       = PetscMPIIntCast((dd->xe-dd->xs)/dof,lsizes+1);CHKERRQ(ierr);
638   ierr       = PetscMPIIntCast(dd->ye-dd->ys,lsizes+2);CHKERRQ(ierr);
639   ierr       = PetscMPIIntCast(dd->ze-dd->zs,lsizes+3);CHKERRQ(ierr);
640   lstarts[0] = 0;
641   ierr       = PetscMPIIntCast(dd->xs/dof,lstarts+1);CHKERRQ(ierr);
642   ierr       = PetscMPIIntCast(dd->ys,lstarts+2);CHKERRQ(ierr);
643   ierr       = PetscMPIIntCast(dd->zs,lstarts+3);CHKERRQ(ierr);
644   ierr       = MPI_Type_create_subarray(da->dim+1,gsizes,lsizes,lstarts,MPI_ORDER_FORTRAN,MPIU_SCALAR,&view);CHKERRQ(ierr);
645   ierr       = MPI_Type_commit(&view);CHKERRQ(ierr);
646 
647   ierr = PetscViewerBinaryGetMPIIODescriptor(viewer,&mfdes);CHKERRQ(ierr);
648   ierr = PetscViewerBinaryGetMPIIOOffset(viewer,&off);CHKERRQ(ierr);
649   ierr = MPI_File_set_view(mfdes,off,MPIU_SCALAR,view,(char*)"native",MPI_INFO_NULL);CHKERRQ(ierr);
650   ierr = VecGetArrayRead(xin,&array);CHKERRQ(ierr);
651   asiz = lsizes[1]*(lsizes[2] > 0 ? lsizes[2] : 1)*(lsizes[3] > 0 ? lsizes[3] : 1)*dof;
652   if (write) {
653     ierr = MPIU_File_write_all(mfdes,(PetscScalar*)array,asiz,MPIU_SCALAR,MPI_STATUS_IGNORE);CHKERRQ(ierr);
654   } else {
655     ierr = MPIU_File_read_all(mfdes,(PetscScalar*)array,asiz,MPIU_SCALAR,MPI_STATUS_IGNORE);CHKERRQ(ierr);
656   }
657   ierr = MPI_Type_get_extent(view,&ul,&ub);CHKERRQ(ierr);
658   ierr = PetscViewerBinaryAddMPIIOOffset(viewer,ub);CHKERRQ(ierr);
659   ierr = VecRestoreArrayRead(xin,&array);CHKERRQ(ierr);
660   ierr = MPI_Type_free(&view);CHKERRQ(ierr);
661   PetscFunctionReturn(0);
662 }
663 #endif
664 
665 #undef __FUNCT__
666 #define __FUNCT__ "VecView_MPI_DA"
667 PetscErrorCode  VecView_MPI_DA(Vec xin,PetscViewer viewer)
668 {
669   DM                da;
670   PetscErrorCode    ierr;
671   PetscInt          dim;
672   Vec               natural;
673   PetscBool         isdraw,isvtk;
674 #if defined(PETSC_HAVE_HDF5)
675   PetscBool         ishdf5;
676 #endif
677   const char        *prefix,*name;
678   PetscViewerFormat format;
679 
680   PetscFunctionBegin;
681   ierr = VecGetDM(xin,&da);CHKERRQ(ierr);
682   if (!da) SETERRQ(PetscObjectComm((PetscObject)xin),PETSC_ERR_ARG_WRONG,"Vector not generated from a DMDA");
683   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
684   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERVTK,&isvtk);CHKERRQ(ierr);
685 #if defined(PETSC_HAVE_HDF5)
686   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERHDF5,&ishdf5);CHKERRQ(ierr);
687 #endif
688   if (isdraw) {
689     ierr = DMDAGetInfo(da,&dim,0,0,0,0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
690     if (dim == 1) {
691       ierr = VecView_MPI_Draw_DA1d(xin,viewer);CHKERRQ(ierr);
692     } else if (dim == 2) {
693       ierr = VecView_MPI_Draw_DA2d(xin,viewer);CHKERRQ(ierr);
694     } else SETERRQ1(PetscObjectComm((PetscObject)da),PETSC_ERR_SUP,"Cannot graphically view vector associated with this dimensional DMDA %D",dim);
695   } else if (isvtk) {           /* Duplicate the Vec and hold a reference to the DM */
696     Vec Y;
697     ierr = PetscObjectReference((PetscObject)da);CHKERRQ(ierr);
698     ierr = VecDuplicate(xin,&Y);CHKERRQ(ierr);
699     if (((PetscObject)xin)->name) {
700       /* If xin was named, copy the name over to Y. The duplicate names are safe because nobody else will ever see Y. */
701       ierr = PetscObjectSetName((PetscObject)Y,((PetscObject)xin)->name);CHKERRQ(ierr);
702     }
703     ierr = VecCopy(xin,Y);CHKERRQ(ierr);
704     ierr = PetscViewerVTKAddField(viewer,(PetscObject)da,DMDAVTKWriteAll,PETSC_VTK_POINT_FIELD,(PetscObject)Y);CHKERRQ(ierr);
705 #if defined(PETSC_HAVE_HDF5)
706   } else if (ishdf5) {
707     ierr = VecView_MPI_HDF5_DA(xin,viewer);CHKERRQ(ierr);
708 #endif
709   } else {
710 #if defined(PETSC_HAVE_MPIIO)
711     PetscBool isbinary,isMPIIO;
712 
713     ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
714     if (isbinary) {
715       ierr = PetscViewerBinaryGetUseMPIIO(viewer,&isMPIIO);CHKERRQ(ierr);
716       if (isMPIIO) {
717         ierr = DMDAArrayMPIIO(da,viewer,xin,PETSC_TRUE);CHKERRQ(ierr);
718         PetscFunctionReturn(0);
719       }
720     }
721 #endif
722 
723     /* call viewer on natural ordering */
724     ierr = PetscObjectGetOptionsPrefix((PetscObject)xin,&prefix);CHKERRQ(ierr);
725     ierr = DMDACreateNaturalVector(da,&natural);CHKERRQ(ierr);
726     ierr = PetscObjectSetOptionsPrefix((PetscObject)natural,prefix);CHKERRQ(ierr);
727     ierr = DMDAGlobalToNaturalBegin(da,xin,INSERT_VALUES,natural);CHKERRQ(ierr);
728     ierr = DMDAGlobalToNaturalEnd(da,xin,INSERT_VALUES,natural);CHKERRQ(ierr);
729     ierr = PetscObjectGetName((PetscObject)xin,&name);CHKERRQ(ierr);
730     ierr = PetscObjectSetName((PetscObject)natural,name);CHKERRQ(ierr);
731 
732     ierr = PetscViewerGetFormat(viewer,&format);CHKERRQ(ierr);
733     if (format == PETSC_VIEWER_BINARY_MATLAB) {
734       /* temporarily remove viewer format so it won't trigger in the VecView() */
735       ierr = PetscViewerSetFormat(viewer,PETSC_VIEWER_DEFAULT);CHKERRQ(ierr);
736     }
737 
738     ierr = VecView(natural,viewer);CHKERRQ(ierr);
739 
740     if (format == PETSC_VIEWER_BINARY_MATLAB) {
741       MPI_Comm    comm;
742       FILE        *info;
743       const char  *fieldname;
744       char        fieldbuf[256];
745       PetscInt    dim,ni,nj,nk,pi,pj,pk,dof,n;
746 
747       /* set the viewer format back into the viewer */
748       ierr = PetscViewerSetFormat(viewer,format);CHKERRQ(ierr);
749       ierr = PetscObjectGetComm((PetscObject)viewer,&comm);CHKERRQ(ierr);
750       ierr = PetscViewerBinaryGetInfoPointer(viewer,&info);CHKERRQ(ierr);
751       ierr = DMDAGetInfo(da,&dim,&ni,&nj,&nk,&pi,&pj,&pk,&dof,0,0,0,0,0);CHKERRQ(ierr);
752       ierr = PetscFPrintf(comm,info,"#--- begin code written by PetscViewerBinary for MATLAB format ---#\n");CHKERRQ(ierr);
753       ierr = PetscFPrintf(comm,info,"#$$ tmp = PetscBinaryRead(fd); \n");CHKERRQ(ierr);
754       if (dim == 1) { ierr = PetscFPrintf(comm,info,"#$$ tmp = reshape(tmp,%d,%d);\n",dof,ni);CHKERRQ(ierr); }
755       if (dim == 2) { ierr = PetscFPrintf(comm,info,"#$$ tmp = reshape(tmp,%d,%d,%d);\n",dof,ni,nj);CHKERRQ(ierr); }
756       if (dim == 3) { ierr = PetscFPrintf(comm,info,"#$$ tmp = reshape(tmp,%d,%d,%d,%d);\n",dof,ni,nj,nk);CHKERRQ(ierr); }
757 
758       for (n=0; n<dof; n++) {
759         ierr = DMDAGetFieldName(da,n,&fieldname);CHKERRQ(ierr);
760         if (!fieldname || !fieldname[0]) {
761           ierr = PetscSNPrintf(fieldbuf,sizeof fieldbuf,"field%D",n);CHKERRQ(ierr);
762           fieldname = fieldbuf;
763         }
764         if (dim == 1) { ierr = PetscFPrintf(comm,info,"#$$ Set.%s.%s = squeeze(tmp(%d,:))';\n",name,fieldname,n+1);CHKERRQ(ierr); }
765         if (dim == 2) { ierr = PetscFPrintf(comm,info,"#$$ Set.%s.%s = squeeze(tmp(%d,:,:))';\n",name,fieldname,n+1);CHKERRQ(ierr); }
766         if (dim == 3) { ierr = PetscFPrintf(comm,info,"#$$ Set.%s.%s = permute(squeeze(tmp(%d,:,:,:)),[2 1 3]);\n",name,fieldname,n+1);CHKERRQ(ierr);}
767       }
768       ierr = PetscFPrintf(comm,info,"#$$ clear tmp; \n");CHKERRQ(ierr);
769       ierr = PetscFPrintf(comm,info,"#--- end code written by PetscViewerBinary for MATLAB format ---#\n\n");CHKERRQ(ierr);
770     }
771 
772     ierr = VecDestroy(&natural);CHKERRQ(ierr);
773   }
774   PetscFunctionReturn(0);
775 }
776 
777 #if defined(PETSC_HAVE_HDF5)
778 #undef __FUNCT__
779 #define __FUNCT__ "VecLoad_HDF5_DA"
780 PetscErrorCode VecLoad_HDF5_DA(Vec xin, PetscViewer viewer)
781 {
782   DM             da;
783   PetscErrorCode ierr;
784   hsize_t        dim;
785   hsize_t        count[5];
786   hsize_t        offset[5];
787   PetscInt       cnt = 0, dimension;
788   PetscScalar    *x;
789   const char     *vecname;
790   hid_t          filespace; /* file dataspace identifier */
791   hid_t          plist_id;  /* property list identifier */
792   hid_t          dset_id;   /* dataset identifier */
793   hid_t          memspace;  /* memory dataspace identifier */
794   hid_t          file_id,group;
795   hid_t          scalartype; /* scalar type (H5T_NATIVE_FLOAT or H5T_NATIVE_DOUBLE) */
796   DM_DA          *dd;
797   PetscBool      dim2;
798 
799   PetscFunctionBegin;
800 #if defined(PETSC_USE_REAL_SINGLE)
801   scalartype = H5T_NATIVE_FLOAT;
802 #elif defined(PETSC_USE_REAL___FLOAT128)
803 #error "HDF5 output with 128 bit floats not supported."
804 #else
805   scalartype = H5T_NATIVE_DOUBLE;
806 #endif
807 
808   ierr = PetscViewerHDF5GetBaseDimension2(viewer,&dim2);CHKERRQ(ierr);
809   ierr = PetscViewerHDF5OpenGroup(viewer, &file_id, &group);CHKERRQ(ierr);
810   ierr = VecGetDM(xin,&da);CHKERRQ(ierr);
811   dd   = (DM_DA*)da->data;
812   ierr = DMGetDimension(da, &dimension);CHKERRQ(ierr);
813 
814   /* Create the dataspace for the dataset */
815   ierr = PetscHDF5IntCast(dimension + ((dd->w == 1 || dim2) ? 0 : 1),&dim);CHKERRQ(ierr);
816 #if defined(PETSC_USE_COMPLEX)
817   dim++;
818 #endif
819 
820   /* Create the dataset with default properties and close filespace */
821   ierr = PetscObjectGetName((PetscObject)xin,&vecname);CHKERRQ(ierr);
822 #if (H5_VERS_MAJOR * 10000 + H5_VERS_MINOR * 100 + H5_VERS_RELEASE >= 10800)
823   PetscStackCallHDF5Return(dset_id,H5Dopen2,(group, vecname, H5P_DEFAULT));
824 #else
825   PetscStackCallHDF5Return(dset_id,H5Dopen,(group, vecname));
826 #endif
827   PetscStackCallHDF5Return(filespace,H5Dget_space,(dset_id));
828 
829   /* Each process defines a dataset and reads it from the hyperslab in the file */
830   cnt = 0;
831   if (dimension == 3) {ierr = PetscHDF5IntCast(dd->zs,offset + cnt++);CHKERRQ(ierr);}
832   if (dimension > 1)  {ierr = PetscHDF5IntCast(dd->ys,offset + cnt++);CHKERRQ(ierr);}
833   ierr = PetscHDF5IntCast(dd->xs/dd->w,offset + cnt++);CHKERRQ(ierr);
834   if (dd->w > 1 || dim2) offset[cnt++] = 0;
835 #if defined(PETSC_USE_COMPLEX)
836   offset[cnt++] = 0;
837 #endif
838   cnt = 0;
839   if (dimension == 3) {ierr = PetscHDF5IntCast(dd->ze - dd->zs,count + cnt++);CHKERRQ(ierr);}
840   if (dimension > 1)  {ierr = PetscHDF5IntCast(dd->ye - dd->ys,count + cnt++);CHKERRQ(ierr);}
841   ierr = PetscHDF5IntCast((dd->xe - dd->xs)/dd->w,count + cnt++);CHKERRQ(ierr);
842   if (dd->w > 1 || dim2) {ierr = PetscHDF5IntCast(dd->w,count + cnt++);CHKERRQ(ierr);}
843 #if defined(PETSC_USE_COMPLEX)
844   count[cnt++] = 2;
845 #endif
846   PetscStackCallHDF5Return(memspace,H5Screate_simple,(dim, count, NULL));
847   PetscStackCallHDF5(H5Sselect_hyperslab,(filespace, H5S_SELECT_SET, offset, NULL, count, NULL));
848 
849   /* Create property list for collective dataset write */
850   PetscStackCallHDF5Return(plist_id,H5Pcreate,(H5P_DATASET_XFER));
851 #if defined(PETSC_HAVE_H5PSET_FAPL_MPIO)
852   PetscStackCallHDF5(H5Pset_dxpl_mpio,(plist_id, H5FD_MPIO_COLLECTIVE));
853 #endif
854   /* To write dataset independently use H5Pset_dxpl_mpio(plist_id, H5FD_MPIO_INDEPENDENT) */
855 
856   ierr   = VecGetArray(xin, &x);CHKERRQ(ierr);
857   PetscStackCallHDF5(H5Dread,(dset_id, scalartype, memspace, filespace, plist_id, x));
858   ierr   = VecRestoreArray(xin, &x);CHKERRQ(ierr);
859 
860   /* Close/release resources */
861   if (group != file_id) {
862     PetscStackCallHDF5(H5Gclose,(group));
863   }
864   PetscStackCallHDF5(H5Pclose,(plist_id));
865   PetscStackCallHDF5(H5Sclose,(filespace));
866   PetscStackCallHDF5(H5Sclose,(memspace));
867   PetscStackCallHDF5(H5Dclose,(dset_id));
868   PetscFunctionReturn(0);
869 }
870 #endif
871 
872 #undef __FUNCT__
873 #define __FUNCT__ "VecLoad_Binary_DA"
874 PetscErrorCode VecLoad_Binary_DA(Vec xin, PetscViewer viewer)
875 {
876   DM             da;
877   PetscErrorCode ierr;
878   Vec            natural;
879   const char     *prefix;
880   PetscInt       bs;
881   PetscBool      flag;
882   DM_DA          *dd;
883 #if defined(PETSC_HAVE_MPIIO)
884   PetscBool isMPIIO;
885 #endif
886 
887   PetscFunctionBegin;
888   ierr = VecGetDM(xin,&da);CHKERRQ(ierr);
889   dd   = (DM_DA*)da->data;
890 #if defined(PETSC_HAVE_MPIIO)
891   ierr = PetscViewerBinaryGetUseMPIIO(viewer,&isMPIIO);CHKERRQ(ierr);
892   if (isMPIIO) {
893     ierr = DMDAArrayMPIIO(da,viewer,xin,PETSC_FALSE);CHKERRQ(ierr);
894     PetscFunctionReturn(0);
895   }
896 #endif
897 
898   ierr = PetscObjectGetOptionsPrefix((PetscObject)xin,&prefix);CHKERRQ(ierr);
899   ierr = DMDACreateNaturalVector(da,&natural);CHKERRQ(ierr);
900   ierr = PetscObjectSetName((PetscObject)natural,((PetscObject)xin)->name);CHKERRQ(ierr);
901   ierr = PetscObjectSetOptionsPrefix((PetscObject)natural,prefix);CHKERRQ(ierr);
902   ierr = VecLoad(natural,viewer);CHKERRQ(ierr);
903   ierr = DMDANaturalToGlobalBegin(da,natural,INSERT_VALUES,xin);CHKERRQ(ierr);
904   ierr = DMDANaturalToGlobalEnd(da,natural,INSERT_VALUES,xin);CHKERRQ(ierr);
905   ierr = VecDestroy(&natural);CHKERRQ(ierr);
906   ierr = PetscInfo(xin,"Loading vector from natural ordering into DMDA\n");CHKERRQ(ierr);
907   ierr = PetscOptionsGetInt(((PetscObject)xin)->prefix,"-vecload_block_size",&bs,&flag);CHKERRQ(ierr);
908   if (flag && bs != dd->w) {
909     ierr = PetscInfo2(xin,"Block size in file %D not equal to DMDA's dof %D\n",bs,dd->w);CHKERRQ(ierr);
910   }
911   PetscFunctionReturn(0);
912 }
913 
914 #undef __FUNCT__
915 #define __FUNCT__ "VecLoad_Default_DA"
916 PetscErrorCode  VecLoad_Default_DA(Vec xin, PetscViewer viewer)
917 {
918   PetscErrorCode ierr;
919   DM             da;
920   PetscBool      isbinary;
921 #if defined(PETSC_HAVE_HDF5)
922   PetscBool ishdf5;
923 #endif
924 
925   PetscFunctionBegin;
926   ierr = VecGetDM(xin,&da);CHKERRQ(ierr);
927   if (!da) SETERRQ(PetscObjectComm((PetscObject)xin),PETSC_ERR_ARG_WRONG,"Vector not generated from a DMDA");
928 
929 #if defined(PETSC_HAVE_HDF5)
930   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERHDF5,&ishdf5);CHKERRQ(ierr);
931 #endif
932   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&isbinary);CHKERRQ(ierr);
933 
934   if (isbinary) {
935     ierr = VecLoad_Binary_DA(xin,viewer);CHKERRQ(ierr);
936 #if defined(PETSC_HAVE_HDF5)
937   } else if (ishdf5) {
938     ierr = VecLoad_HDF5_DA(xin,viewer);CHKERRQ(ierr);
939 #endif
940   } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Viewer type %s not supported for vector loading", ((PetscObject)viewer)->type_name);
941   PetscFunctionReturn(0);
942 }
943