fortanmpi.txt

用fortran+MPI编写的jacobi迭代求解源码

program main
include ‘mpif.h’
integer totalsize,mysize,steps
Parameter (totalsize=16)

parameter (mysize=totalsize/4,steps=10)

integer n,myid,numprocs,i,j,rc
Real a(totalsize,mysize+2),b(totalsize,mysize+2)

Integer begin_col,end_col,ierr
Integer status(MPI_STATUS_SIZE)
call MPI_INIT(ierr)
call MPI_COMM_RANK(MPI_COMM_WORLD,myid,ierr)
call MPI_COMM_SIZE(MPI_COMM_WORLD,numprocs,ierr)
print *,”Process”,myid,”  of”,numprocs,”  is alive”


do j=1,mysize+2
     do i=1,totalsize
          a(i,j)=0.0
     end do
end do

If (myid.eq.0) then
     do i=1,totalsize
           a(i,2)=8.0
     end do
end if
If (myid.eq.3) then
     do i=1,totalsize
           a(i,mysize+1)=8.0
     end do
end if

do i=1,mysize+2
     a(1,i)=8.0
     a(totalsize,i)=8.0
end do
(Jacobi迭代部分)
do n=1,steps

if (myid .lt. 3) then
call MPI_RECV(a(1,mysize+2),totalsize,MPI_REAL,myid+1,10,
* MPI_COMM_WORLD,status,ierr)
end if

if ((myid .gt. 0) ) then
call MPI_SEND(a(1,2),totalsize,MPI_REAL,myid-1,10,
* MPI_COMM_WORLD,ierr)
end if

if (myid .lt. 3) then
call MPI_SEND(a(1,mysize+1),totalsize,MPI_REAL,myid+1,10,
* MPI_COMM_WORLD,ierr)
end if

if (myid .gt. 0) then
call MPI_RECV(a(1,1),totalsize,MPI_REAL,myid-1,10,
MPI_COMM_WORLD,status,ierr)
end if
begin_col=2
end_col=mysize+1
if (myid .eq. 0) then
begin_col=3
endif
if (myid .eq. 3) then
end_col=mysize
endif
do j=begin_col,end_col
do i=2,totalsize-1
b(i,j)=(a(i,j+1)+a(i,j-1)+a(i+1,j)+a(i-1,j))*0.25
end do
end do
do j=begin_col,end_col
do i=2,totalsize-1
a(i,j)=b(i,j)
end do
end do
end do
do i=2,totalsize-1
print *, myid,(a(i,j),j=begin_col,end_col)
end do
call MPI_Finalize(rc)
end