! ! "$Id: ex1f90.F,v 1.27 2001/08/07 03:02:34 balay Exp $" ! !/*T ! Concepts: vectors^using basic vector routines; ! Concepts: Fortran90^using basic vector routines; ! Processors: n !T*/ ! ! ----------------------------------------------------------------------- program main implicit none ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! Include files ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! ! The following include statements are required for Fortran programs ! that use PETSc vectors: ! petsc.h - base PETSc routines ! petscvec.h - vectors ! petscvec.h90 - to allow access to Fortran90 features of vectors ! ! Additional include statements may be needed if using additional ! PETSc routines in a Fortran program, e.g., ! petscviewer.h - viewers ! petscis.h - index sets ! #include "include/finclude/petsc.h" #include "include/finclude/petscvec.h" #include "include/finclude/petscvec.h90" ! ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! Variable declarations ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! ! Variables: ! x, y, w - vectors ! z - array of vectors ! Vec x,y,w Vec, pointer :: z(:) double precision norm,v,v1,v2 integer n,ierr,flg,rank PetscScalar one,two,three,dots(3),dot ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! Beginning of program ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - call PetscInitialize(PETSC_NULL_CHARACTER,ierr) one = 1.0 two = 2.0 three = 3.0 n = 20 call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-n',n,flg,ierr) call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr) ! Create a vector, specifying only its global dimension. ! When using VecCreate(), VecSetSizes() and VecSetFromOptions(), ! the vector format (currently parallel ! or sequential) is determined at runtime. Also, the parallel ! partitioning of the vector is determined by PETSc at runtime. ! ! Routines for creating particular vector types directly are: ! VecCreateSeq() - uniprocessor vector ! VecCreateMPI() - distributed vector, where the user can ! determine the parallel partitioning call VecCreate(PETSC_COMM_WORLD,x,ierr) call VecSetSizes(x,PETSC_DECIDE,n,ierr) call VecSetFromOptions(x,ierr) ! Duplicate some work vectors (of the same format and ! partitioning as the initial vector). call VecDuplicate(x,y,ierr) call VecDuplicate(x,w,ierr) ! Duplicate more work vectors (of the same format and ! partitioning as the initial vector). Here we duplicate ! an array of vectors, which is often more convenient than ! duplicating individual ones. call VecDuplicateVecsF90(x,3,z,ierr) ! Set the vectors to entries to a constant value. call VecSet(one,x,ierr) call VecSet(two,y,ierr) call VecSet(one,z(1),ierr) call VecSet(two,z(2),ierr) call VecSet(three,z(3),ierr) ! Demonstrate various basic vector routines. call VecDot(x,x,dot,ierr) call VecMDot(3,x,z,dots,ierr) ! Note: If using a complex numbers version of PETSc, then ! PETSC_USE_COMPLEX is defined in the makefiles; otherwise, ! (when using real numbers) it is undefined. if (rank .eq. 0) then #if defined(PETSC_USE_COMPLEX) write(6,100) int(PetscRealPart(dot)) write(6,110) int(PetscRealPart(dots(1))), & & int(PetscRealPart(dots(2))), & & int(PetscRealPart(dots(3))) #else write(6,100) int(dot) write(6,110) int(dots(1)),int(dots(2)),int(dots(3)) #endif write(6,120) endif 100 format ("Vector length ",i6) 110 format ("Vector length ",3(i6)) 120 format ("All other values should be near zero") call VecScale(two,x,ierr) call VecNorm(x,NORM_2,norm,ierr) v = norm-2.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,130) v 130 format ("VecScale ",1pe8.2) call VecCopy(x,w,ierr) call VecNorm(w,NORM_2,norm,ierr) v = norm-2.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,140) v 140 format ("VecCopy ",1pe8.2) call VecAXPY(three,x,y,ierr) call VecNorm(y,NORM_2,norm,ierr) v = norm-8.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,150) v 150 format ("VecAXPY ",1pe8.2) call VecAYPX(two,x,y,ierr) call VecNorm(y,NORM_2,norm,ierr) v = norm-18.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,160) v 160 format ("VecAYXP ",1pe8.2) call VecSwap(x,y,ierr) call VecNorm(y,NORM_2,norm,ierr) v = norm-2.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,170) v 170 format ("VecSwap ",1pe8.2) call VecNorm(x,NORM_2,norm,ierr) v = norm-18.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,180) v 180 format ("VecSwap ",1pe8.2) call VecWAXPY(two,x,y,w,ierr) call VecNorm(w,NORM_2,norm,ierr) v = norm-38.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,190) v 190 format ("VecWAXPY ",1pe8.2) call VecPointwiseMult(y,x,w,ierr) call VecNorm(w,NORM_2,norm,ierr) v = norm-36.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,200) v 200 format ("VecPointwiseMult ",1pe8.2) call VecPointwiseDivide(x,y,w,ierr) call VecNorm(w,NORM_2,norm,ierr) v = norm-9.0*sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 if (rank .eq. 0) write(6,210) v 210 format ("VecPointwiseDivide ",1pe8.2) dots(1) = one dots(2) = three dots(3) = two call VecSet(one,x,ierr) call VecMAXPY(3,dots,x,z,ierr) call VecNorm(z(1),NORM_2,norm,ierr) v = norm-sqrt(dble(n)) if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0 call VecNorm(z(2),NORM_2,norm,ierr) v1 = norm-2.0*sqrt(dble(n)) if (v1 .gt. -1.d-10 .and. v1 .lt. 1.d-10) v1 = 0.0 call VecNorm(z(3),NORM_2,norm,ierr) v2 = norm-3.0*sqrt(dble(n)) if (v2 .gt. -1.d-10 .and. v2 .lt. 1.d-10) v2 = 0.0 if (rank .eq. 0) write(6,220) v,v1,v2 220 format ("VecMAXPY ",3(1pe8.2)) ! Test whether vector has been corrupted (just to demonstrate this ! routine) not needed in most application codes. call VecValid(x,flg,ierr) if (flg .ne. PETSC_TRUE) then if (rank .eq. 0) then write(6,*) 'Corrupted vector!' endif SETERRQ(1,' ',ierr) endif ! Free work space. All PETSc objects should be destroyed when they ! are no longer needed. call VecDestroy(x,ierr) call VecDestroy(y,ierr) call VecDestroy(w,ierr) call VecDestroyVecsF90(z,3,ierr) call PetscFinalize(ierr) end