Actual source code: ex5f.F90

petsc-master 2019-11-16
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  1: program main
  2:  #include <petsc/finclude/petscvec.h>
  3: use petscvec
  4: implicit none

  6:   PetscErrorCode ::ierr
  7:   PetscMPIInt ::   rank,mySize
  8:   PetscInt :: i
  9:   PetscInt, parameter :: one = 1
 10:   PetscInt :: m = 10
 11:   PetscInt :: low,high,ldim,iglobal
 12:   PetscScalar :: v
 13:   Vec ::         u
 14:   PetscViewer :: viewer
 15: 
 16:   PetscBool :: flg
 17: #if defined(PETSC_USE_LOG)
 18:   PetscLogEvent  VECTOR_GENERATE,VECTOR_READ
 19: #endif

 21:   call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
 22:   if (ierr /= 0) then
 23:    print*,'PetscInitialize failed'
 24:    stop
 25:   endif
 26: 
 27:   call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)
 28: 
 29:   call MPI_Comm_size(PETSC_COMM_WORLD,mySize,ierr);CHKERRA(ierr)  !gives number of processes in the group of comm (integer)
 30:   call PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,"-m",m,flg,ierr);CHKERRA(ierr) !gives the integer value for a particular option in the database.

 32:   ! PART 1:  Generate vector, then write it in binary format */

 34:   call PetscLogEventRegister("Generate Vector",0,VECTOR_GENERATE,ierr);CHKERRA(ierr)
 35:   call PetscLogEventBegin(VECTOR_GENERATE,ierr);CHKERRA(ierr)
 36:   ! Generate vector
 37:   call VecCreate(PETSC_COMM_WORLD,u,ierr);CHKERRA(ierr)
 38:   call VecSetSizes(u,PETSC_DECIDE,m,ierr);CHKERRA(ierr)
 39:   call VecSetFromOptions(u,ierr);CHKERRA(ierr)
 40:   call VecGetOwnershipRange(u,low,high,ierr);CHKERRA(ierr)
 41:   call VecGetLocalSize(u,ldim,ierr);CHKERRA(ierr)
 42:   do i=0,ldim-1
 43:    iglobal = i + low
 44:    v       = real(i + 100*rank)
 45:    call VecSetValues(u,one,iglobal,v,INSERT_VALUES,ierr);CHKERRA(ierr)
 46:   end do
 47:   call VecAssemblyBegin(u,ierr);CHKERRA(ierr)
 48:   call VecAssemblyEnd(u,ierr);CHKERRA(ierr)
 49:   call VecView(u,PETSC_VIEWER_STDOUT_WORLD,ierr);CHKERRA(ierr)

 51:   call PetscPrintf(PETSC_COMM_WORLD,"writing vector in binary to vector.dat ...\n",ierr);CHKERRA(ierr)
 52:   call PetscViewerBinaryOpen(PETSC_COMM_WORLD,"vector.dat",FILE_MODE_WRITE,viewer,ierr);CHKERRA(ierr)
 53:   call VecView(u,viewer,ierr);CHKERRA(ierr)
 54:   call PetscViewerDestroy(viewer,ierr);CHKERRA(ierr)
 55:   call VecDestroy(u,ierr);CHKERRA(ierr)
 56:   call PetscOptionsSetValue(PETSC_NULL_OPTIONS,"-viewer_binary_mpiio",PETSC_NULL_CHARACTER,ierr);CHKERRA(ierr)

 58:   call PetscLogEventEnd(VECTOR_GENERATE,ierr);CHKERRA(ierr)

 60:   ! PART 2:  Read in vector in binary format

 62:   ! Read new vector in binary format
 63:   call PetscLogEventRegister("Read Vector",0,VECTOR_READ,ierr);CHKERRA(ierr)
 64:   call PetscLogEventBegin(VECTOR_READ,ierr);CHKERRA(ierr)
 65:   call PetscPrintf(PETSC_COMM_WORLD,"reading vector in binary from vector.dat ...\n",ierr);CHKERRA(ierr)
 66:   call PetscViewerBinaryOpen(PETSC_COMM_WORLD,"vector.dat",FILE_MODE_READ,viewer,ierr);CHKERRA(ierr)
 67:   call VecCreate(PETSC_COMM_WORLD,u,ierr);CHKERRA(ierr)
 68:   call VecLoad(u,viewer,ierr);CHKERRA(ierr)
 69:   call PetscViewerDestroy(viewer,ierr);CHKERRA(ierr)

 71:   call PetscLogEventEnd(VECTOR_READ,ierr);CHKERRA(ierr)
 72:   call VecView(u,PETSC_VIEWER_STDOUT_WORLD,ierr);CHKERRA(ierr)

 74:   ! Free data structures
 75:   call VecDestroy(u,ierr);CHKERRA(ierr)
 76:   call PetscFinalize(ierr);CHKERRA(ierr)
 77: 
 78: end program


 81: !/*TEST
 82: !
 83: !     test:
 84: !       nsize: 1
 85: !       requires: mpiio
 86: !       output_file: output/ex5_1.out
 87: !
 88: !     test:
 89: !       suffix: 2
 90: !       nsize: 2
 91: !       requires: mpiio
 92: !       output_file: output/ex5_2.out
 93: !
 94: !TEST*/