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*/