symm_ed Subroutine

 subroutine symm_ed(im, lamda, theta)
! Make grid symmetrical to i=im/2+1
 integer im
 real(ESMF_KIND_R8) lamda(im+1,im+1)
 real(ESMF_KIND_R8) theta(im+1,im+1)
 integer i,j,ip,jp
 real(ESMF_KIND_R8) avg

 do j=2,im+1
    do i=2,im
       lamda(i,j) = lamda(i,1)
    enddo
 enddo

 do j=1,im+1
    do i=1,im/2
       ip = im + 2 - i
       avg = 0.5*(lamda(i,j)-lamda(ip,j))
       lamda(i, j) = avg + pi
       lamda(ip,j) = pi - avg 
       avg = 0.5*(theta(i,j)+theta(ip,j))
       theta(i, j) = avg
       theta(ip,j) = avg
    enddo
 enddo

! Make grid symmetrical to j=im/2+1
 do j=1,im/2
       jp = im + 2 - j
    do i=2,im
       avg = 0.5*(lamda(i,j)+lamda(i,jp))
       lamda(i, j) = avg
       lamda(i,jp) = avg
       avg = 0.5*(theta(i,j)-theta(i,jp))
       theta(i, j) =  avg
       theta(i,jp) = -avg
    enddo
 enddo

 end subroutine symm_ed