Actual source code: ex6f.F90
1: program main
2: #include <petsc/finclude/petscvec.h>
3: use petscvec
5: implicit none
7: PetscErrorCode ierr
8: PetscMPIInt :: size
9: integer :: fd
10: PetscInt :: i,sz
11: PetscInt,parameter :: m = 10
12: PetscInt,parameter :: one = 1
13: PetscInt, allocatable,dimension(:) :: t
14: PetscScalar, pointer, dimension(:) :: avec
15: PetscScalar, pointer, dimension(:) :: array
16: Vec vec
17: PetscViewer view_out,view_in
18: character(len=256) :: outstring
19: PetscBool :: flg
21: PetscCallA(PetscInitialize(ierr))
23: PetscCallMPIA(MPI_Comm_size(PETSC_COMM_WORLD,size,ierr))
24: PetscCheckA(size .eq. 1,PETSC_COMM_SELF,PETSC_ERR_WRONG_MPI_SIZE,'This is a uniprocessor example only!')
26: PetscCallA(PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-m',m,flg,ierr))
28: ! ----------------------------------------------------------------------
29: ! PART 1: Write some data to a file in binary format
30: ! ----------------------------------------------------------------------
32: ! Allocate array and set values
34: allocate(array(0:m-1))
35: do i=0,m-1
36: array(i) = real(i)*10.0
37: end do
39: allocate(t(1))
40: t(1) = m
41: ! Open viewer for binary output
42: PetscCallA(PetscViewerBinaryOpen(PETSC_COMM_SELF,'input.dat',FILE_MODE_WRITE,view_out,ierr))
43: PetscCallA(PetscViewerBinaryGetDescriptor(view_out,fd,ierr))
45: ! Write binary output
46: PetscCallA(PetscBinaryWrite(fd,t,one,PETSC_INT,ierr))
47: PetscCallA(PetscBinaryWrite(fd,array,m,PETSC_SCALAR,ierr))
49: ! Destroy the output viewer and work array
50: PetscCallA(PetscViewerDestroy(view_out,ierr))
51: deallocate(array)
53: ! ----------------------------------------------------------------------
54: ! PART 2: Read data from file and form a vector
55: ! ----------------------------------------------------------------------
57: ! Open input binary viewer
58: PetscCallA(PetscViewerBinaryOpen(PETSC_COMM_SELF,'input.dat',FILE_MODE_READ,view_in,ierr))
59: PetscCallA(PetscViewerBinaryGetDescriptor(view_in,fd,ierr))
61: ! Create vector and get pointer to data space
62: PetscCallA(VecCreate(PETSC_COMM_SELF,vec,ierr))
63: PetscCallA(VecSetSizes(vec,PETSC_DECIDE,m,ierr))
65: PetscCallA(VecSetFromOptions(vec,ierr))
67: PetscCallA(VecGetArrayF90(vec,avec,ierr))
69: ! Read data into vector
70: PetscCallA(PetscBinaryRead(fd,t,one,PETSC_NULL_INTEGER,PETSC_INT,ierr))
71: sz=t(1)
73: PetscCheckA(sz >= 0,PETSC_COMM_SELF,PETSC_ERR_USER,'Error: Must have array length > 0')
75: write(outstring,'(a,i2.2,a)') 'reading data in binary from input.dat, sz =', sz, ' ...\n'
76: PetscCallA(PetscPrintf(PETSC_COMM_SELF,trim(outstring),ierr))
78: PetscCallA(PetscBinaryRead(fd,avec,sz,PETSC_NULL_INTEGER,PETSC_SCALAR,ierr))
80: ! View vector
81: PetscCallA(VecRestoreArrayF90(vec,avec,ierr))
82: PetscCallA(VecView(vec,PETSC_VIEWER_STDOUT_SELF,ierr))
84: ! Free data structures
85: deallocate(t)
86: PetscCallA(VecDestroy(vec,ierr))
87: PetscCallA(PetscViewerDestroy(view_in,ierr))
88: PetscCallA(PetscFinalize(ierr))
90: end program
92: !/*TEST
93: !
94: ! test:
95: ! output_file: output/ex6_1.out
96: !
97: !TEST*/