xref: /petsc/src/dm/tutorials/ex10.c (revision dfd57a172ac9fa6c7b5fe6de6ab5df85cefc2996)
1c4762a1bSJed Brown /*
2c4762a1bSJed Brown    Demonstrates using the HDF5 viewer with a DMDA Vec
3c4762a1bSJed Brown  - create a global vector containing a gauss profile (exp(-x^2-y^2))
4c4762a1bSJed Brown  - write the global vector in a hdf5 file
5c4762a1bSJed Brown 
6c4762a1bSJed Brown    The resulting file gauss.h5 can be viewed with Visit (an open source visualization package)
7c4762a1bSJed Brown    Or with some versions of MATLAB with data=hdfread('gauss.h5','pressure'); mesh(data);
8c4762a1bSJed Brown 
9c4762a1bSJed Brown    The file storage of the vector is independent of the number of processes used.
10c4762a1bSJed Brown  */
11c4762a1bSJed Brown 
12c4762a1bSJed Brown #include <petscdm.h>
13c4762a1bSJed Brown #include <petscdmda.h>
14c4762a1bSJed Brown #include <petscsys.h>
15c4762a1bSJed Brown #include <petscviewerhdf5.h>
16c4762a1bSJed Brown 
17c4762a1bSJed Brown static char help[] = "Test to write HDF5 file from PETSc DMDA Vec.\n\n";
18c4762a1bSJed Brown 
19c4762a1bSJed Brown int main(int argc,char **argv)
20c4762a1bSJed Brown {
21c4762a1bSJed Brown   PetscErrorCode ierr;
22c4762a1bSJed Brown   DM             da2D;
23c4762a1bSJed Brown   PetscInt       i,j,ixs, ixm, iys, iym;
24c4762a1bSJed Brown   PetscViewer    H5viewer;
25c4762a1bSJed Brown   PetscScalar    xm    = -1.0, xp=1.0;
26c4762a1bSJed Brown   PetscScalar    ym    = -1.0, yp=1.0;
27c4762a1bSJed Brown   PetscScalar    value = 1.0,dx,dy;
28c4762a1bSJed Brown   PetscInt       Nx    = 40, Ny=40;
29c4762a1bSJed Brown   Vec            gauss,input;
30c4762a1bSJed Brown   PetscScalar    **gauss_ptr;
31c4762a1bSJed Brown   PetscReal      norm;
32c4762a1bSJed Brown   const char     *vecname;
33c4762a1bSJed Brown 
34c4762a1bSJed Brown   dx=(xp-xm)/(Nx-1);
35c4762a1bSJed Brown   dy=(yp-ym)/(Ny-1);
36c4762a1bSJed Brown 
37c4762a1bSJed Brown   /* Initialize the Petsc context */
38c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
39c4762a1bSJed Brown   ierr = DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,Nx,Ny,PETSC_DECIDE,PETSC_DECIDE,1,1,NULL,NULL,&da2D);CHKERRQ(ierr);
40c4762a1bSJed Brown   ierr = DMSetFromOptions(da2D);CHKERRQ(ierr);
41c4762a1bSJed Brown   ierr = DMSetUp(da2D);CHKERRQ(ierr);
42c4762a1bSJed Brown 
43c4762a1bSJed Brown   /* Set the coordinates */
44c4762a1bSJed Brown   ierr = DMDASetUniformCoordinates(da2D, 0.0, 1.0, 0.0, 1.0, 0.0, 0.0);CHKERRQ(ierr);
45c4762a1bSJed Brown 
46c4762a1bSJed Brown   /* Declare gauss as a DMDA component */
47c4762a1bSJed Brown   ierr = DMCreateGlobalVector(da2D,&gauss);CHKERRQ(ierr);
48c4762a1bSJed Brown   ierr = PetscObjectSetName((PetscObject) gauss, "pressure");CHKERRQ(ierr);
49c4762a1bSJed Brown 
50c4762a1bSJed Brown   /* Initialize vector gauss with a constant value (=1) */
51c4762a1bSJed Brown   ierr = VecSet(gauss,value);CHKERRQ(ierr);
52c4762a1bSJed Brown 
53c4762a1bSJed Brown   /* Get the coordinates of the corners for each process */
54c4762a1bSJed Brown   ierr = DMDAGetCorners(da2D, &ixs, &iys, 0, &ixm, &iym, 0);CHKERRQ(ierr);
55c4762a1bSJed Brown 
56c4762a1bSJed Brown   /* Build the gaussian profile (exp(-x^2-y^2)) */
57c4762a1bSJed Brown   ierr = DMDAVecGetArray(da2D,gauss,&gauss_ptr);CHKERRQ(ierr);
58c4762a1bSJed Brown   for (j=iys; j<iys+iym; j++) {
59c4762a1bSJed Brown     for (i=ixs; i<ixs+ixm; i++) {
60c4762a1bSJed Brown       gauss_ptr[j][i]=PetscExpScalar(-(xm+i*dx)*(xm+i*dx)-(ym+j*dy)*(ym+j*dy));
61c4762a1bSJed Brown     }
62c4762a1bSJed Brown   }
63c4762a1bSJed Brown   ierr = DMDAVecRestoreArray(da2D,gauss,&gauss_ptr);CHKERRQ(ierr);
64c4762a1bSJed Brown 
65c4762a1bSJed Brown   /* Create the HDF5 viewer */
66c4762a1bSJed Brown   ierr = PetscViewerHDF5Open(PETSC_COMM_WORLD,"gauss.h5",FILE_MODE_WRITE,&H5viewer);CHKERRQ(ierr);
67c4762a1bSJed Brown   ierr = PetscViewerSetFromOptions(H5viewer);CHKERRQ(ierr);
68c4762a1bSJed Brown 
69c4762a1bSJed Brown   /* Write the H5 file */
70c4762a1bSJed Brown   ierr = VecView(gauss,H5viewer);CHKERRQ(ierr);
71c4762a1bSJed Brown 
72c4762a1bSJed Brown   /* Close the viewer */
73c4762a1bSJed Brown   ierr = PetscViewerDestroy(&H5viewer);CHKERRQ(ierr);
74c4762a1bSJed Brown 
75c4762a1bSJed Brown   ierr = VecDuplicate(gauss,&input);CHKERRQ(ierr);
76c4762a1bSJed Brown   ierr = PetscObjectGetName((PetscObject)gauss,&vecname);CHKERRQ(ierr);
77c4762a1bSJed Brown   ierr = PetscObjectSetName((PetscObject)input,vecname);CHKERRQ(ierr);
78c4762a1bSJed Brown 
79c4762a1bSJed Brown   /* Create the HDF5 viewer for reading */
80c4762a1bSJed Brown   ierr = PetscViewerHDF5Open(PETSC_COMM_WORLD,"gauss.h5",FILE_MODE_READ,&H5viewer);CHKERRQ(ierr);
81c4762a1bSJed Brown   ierr = PetscViewerSetFromOptions(H5viewer);CHKERRQ(ierr);
82c4762a1bSJed Brown   ierr = VecLoad(input,H5viewer);CHKERRQ(ierr);
83c4762a1bSJed Brown   ierr = PetscViewerDestroy(&H5viewer);CHKERRQ(ierr);
84c4762a1bSJed Brown 
85c4762a1bSJed Brown   ierr = VecAXPY(input,-1.0,gauss);CHKERRQ(ierr);
86c4762a1bSJed Brown   ierr = VecNorm(input,NORM_2,&norm);CHKERRQ(ierr);
87c4762a1bSJed Brown   if (norm > 1.e-6) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Vec read in does not match vector written out");
88c4762a1bSJed Brown 
89c4762a1bSJed Brown   ierr = VecDestroy(&input);CHKERRQ(ierr);
90c4762a1bSJed Brown   ierr = VecDestroy(&gauss);CHKERRQ(ierr);
91c4762a1bSJed Brown   ierr = DMDestroy(&da2D);CHKERRQ(ierr);
92c4762a1bSJed Brown   ierr = PetscFinalize();
93c4762a1bSJed Brown   return ierr;
94c4762a1bSJed Brown }
95c4762a1bSJed Brown 
96c4762a1bSJed Brown /*TEST
97c4762a1bSJed Brown 
98c4762a1bSJed Brown       build:
99*dfd57a17SPierre Jolivet          requires: hdf5 !defined(PETSC_USE_CXXCOMPLEX)
100c4762a1bSJed Brown 
101c4762a1bSJed Brown       test:
102c4762a1bSJed Brown          nsize: 4
103c4762a1bSJed Brown 
104c4762a1bSJed Brown       test:
105c4762a1bSJed Brown          nsize: 4
106c4762a1bSJed Brown          suffix: 2
107c4762a1bSJed Brown          args: -viewer_hdf5_base_dimension2
108c4762a1bSJed Brown          output_file: output/ex10_1.out
109c4762a1bSJed Brown 
110c4762a1bSJed Brown       test:
111c4762a1bSJed Brown          nsize: 4
112c4762a1bSJed Brown          suffix: 3
113c4762a1bSJed Brown          args: -viewer_hdf5_sp_output
114c4762a1bSJed Brown          output_file: output/ex10_1.out
115c4762a1bSJed Brown 
116c4762a1bSJed Brown TEST*/
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