xref: /petsc/src/dm/tutorials/ex7.c (revision b122ec5aa1bd4469eb4e0673542fb7de3f411254)
1 static char help[] = "Demonstrates using PetscViewerPushFormat(viewer,PETSC_VIEWER_BINARY_MATLAB)\n\n";
2 
3 /*T
4    Concepts: viewers
5    Concepts: bags
6    Processors: n
7 T*/
8 #include <petscsys.h>
9 #include <petscdm.h>
10 #include <petscdmda.h>
11 #include <petscbag.h>
12 
13 typedef struct {
14   char      filename[PETSC_MAX_PATH_LEN];
15   PetscReal ra;
16   PetscInt  ia;
17   PetscBool ta;
18 } Parameter;
19 
20 int main(int argc,char **argv)
21 {
22   PetscBag       bag;
23   Parameter      *params;
24   PetscViewer    viewer;
25   DM             da;
26   Vec            global,local;
27   PetscMPIInt    rank;
28 
29   /*
30     Every PETSc routine should begin with the PetscInitialize() routine.
31     argc, argv - These command line arguments are taken to extract the options
32                  supplied to PETSc and options supplied to MPI.
33     help       - When PETSc executable is invoked with the option -help,
34                  it prints the various options that can be applied at
35                  runtime.  The user can use the "help" variable place
36                  additional help messages in this printout.
37   */
38   CHKERRQ(PetscInitialize(&argc,&argv,(char*)0,help));
39   /* Create a DMDA and an associated vector */
40   CHKERRQ(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,10,10,PETSC_DECIDE,PETSC_DECIDE,2,1,NULL,NULL,&da));
41   CHKERRQ(DMSetFromOptions(da));
42   CHKERRQ(DMSetUp(da));
43   CHKERRQ(DMCreateGlobalVector(da,&global));
44   CHKERRQ(DMCreateLocalVector(da,&local));
45   CHKERRQ(VecSet(global,-1.0));
46   CHKERRQ(DMGlobalToLocalBegin(da,global,INSERT_VALUES,local));
47   CHKERRQ(DMGlobalToLocalEnd(da,global,INSERT_VALUES,local));
48   CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
49   CHKERRQ(VecScale(local,rank+1));
50   CHKERRQ(DMLocalToGlobalBegin(da,local,ADD_VALUES,global));
51   CHKERRQ(DMLocalToGlobalEnd(da,local,ADD_VALUES,global));
52 
53   /* Create an empty bag */
54   CHKERRQ(PetscBagCreate(PETSC_COMM_WORLD,sizeof(Parameter),&bag));
55   CHKERRQ(PetscBagGetData(bag,(void**)&params));
56 
57   /* fill bag: register variables, defaults, names, help strings */
58   CHKERRQ(PetscBagSetName(bag,"ParameterBag","contains problem parameters"));
59   CHKERRQ(PetscBagRegisterString(bag,&params->filename,PETSC_MAX_PATH_LEN,"output_file","filename","Name of secret file"));
60   CHKERRQ(PetscBagRegisterReal  (bag,&params->ra,1.0,"param_1","The first parameter"));
61   CHKERRQ(PetscBagRegisterInt   (bag,&params->ia,5,"param_2","The second parameter"));
62   CHKERRQ(PetscBagRegisterBool (bag,&params->ta,PETSC_TRUE,"do_output","Write output file (true/false)"));
63 
64   /*
65      Write output file with PETSC_VIEWER_BINARY_MATLAB format
66      NOTE: the output generated with this viewer can be loaded into
67      MATLAB using $PETSC_DIR/share/petsc/matlab/PetscReadBinaryMatlab.m
68   */
69   CHKERRQ(PetscViewerBinaryOpen(PETSC_COMM_WORLD,params->filename,FILE_MODE_WRITE,&viewer));
70   CHKERRQ(PetscViewerPushFormat(viewer,PETSC_VIEWER_BINARY_MATLAB));
71   CHKERRQ(PetscBagView(bag,viewer));
72   CHKERRQ(DMDASetFieldName(da,0,"field1"));
73   CHKERRQ(DMDASetFieldName(da,1,"field2"));
74   CHKERRQ(PetscObjectSetName((PetscObject)global,"da1"));
75   CHKERRQ(VecView(global,viewer));
76   CHKERRQ(PetscViewerPopFormat(viewer));
77   CHKERRQ(PetscViewerDestroy(&viewer));
78 
79   /* clean up and exit */
80   CHKERRQ(PetscBagDestroy(&bag));
81   CHKERRQ(DMDestroy(&da));
82   CHKERRQ(VecDestroy(&local));
83   CHKERRQ(VecDestroy(&global));
84   CHKERRQ(PetscFinalize());
85   return 0;
86 }
87 
88 /*TEST
89 
90    test:
91 
92 TEST*/
93