subroutine connect
c
c     loads arrays to do ffts on connected domain,
c     instead of using extensions
c
      implicit none	
      include 'itg.par'
      include 'itg.cmn'
      integer jmax,kmax,jshift,jshift0,l(-nz:nz,0:mz),j,k
      integer t,m,n
      integer count,jj,i

      jmax=(nd-1)/2
      kmax=md-1
      jshift0=(xp+.0001)/z0*(nd-1)
      if (jshift0.eq.0) jshift0=nz**2
      
      if((x0.ne.xp) .or. (abs(int((x0+.0001)/pi)*pi-x0).gt. 0.001)
     .     .or. (abs(int((xp+.0001)/pi)*pi-xp).gt. 0.001)) then
         write(*,*) 'failure in connect.f:'
         write(*,*) ' for iconnect=3, must have x0=xp=pi * integer'
         call aborter(6,' ')
      endif

c      write(*,*) 'jmax=',jmax,' kmax=',kmax,' jshift(k=1)=',jshift0
c
c     Calculate how many domains are connected by the BC
c
      do j=-jmax,jmax
         l(j,0)=1
      enddo

      do k=1,kmax
        jshift=jshift0*k 
        if (lin.eq.1 .and. layout.eq.'linear') jshift=jshift0
        do j=-jmax,jmax
          l(j,k)=(jmax-j)/jshift+(j+jmax)/jshift+1 
          if (j+jmax.ge.jshift) l(j,k)=0
c          if ((j.lt.0).and.(l(j,k).gt.1)) l(j,k)=0
        enddo
      enddo   

c      write(*,*) 'jshift(k=1): ',jshift0
c      write(*,100) 0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
 100  format(i5,17(i3))
c      do j=-jmax,jmax
c         write(*,100) j,(l(j,k),k=0,kmax)
c      enddo

      t=0
      ndom=1
      do m=1,jmax*2+1
        ncon(ndom)=0 
        do k=0,kmax 
          do j=-jmax,jmax
            if (l(j,k).eq.m) then  
              ncon(ndom)=ncon(ndom)+1 
              scon(ndom)=m
              if (m.gt.nconz) write(*,*) 
     .             'nconz too small, must be at least ',m
              if (ndom.gt.ndomz) write(*,*) 
     .             'ndomz too small, must be at least ',ndom
            endif  
          enddo
        enddo
        t=t+ncon(ndom)*m
c        if (ncon(ndom).ne.0) write(*,101) m,ncon(ndom)
c 101    format ('# of connections with m=',i3,': ',i3)
        if (ncon(ndom).gt.0) ndom=ndom+1
      enddo
      ndom=ndom-1
      write(*,*) 'total # of domains: ',ndom
      write(*,102) t,(2*jmax+1)*(kmax+1)
 102  format('Total modes accounted for: ',i4,
     &  '=(2*jmax+1)*(kmax+1)=',i4)

      do n=1,nd
         do m=1,md
            j=nrr(n)
            k=mrr(m,n)
            mcon(m,n)=0
            jshift=jshift0*k 
            if (lin.eq.1 .and. layout.eq.'linear') jshift=jshift0
            if (k.ne.0) then
              icon(m,n)=(jmax-j)/jshift+(j+jmax)/jshift+1 
              conpos(m,n)=1+(jmax-j)/jshift
            else
              icon(m,n)=1
              conpos(m,n)=1
            endif  
         enddo
      enddo   

      do i=1,ndom
        count=1 
        do k=0,md-1
          do j=-jmax,jmax
            if (l(j,k).eq.scon(i)) then 
              do jj=1,l(j,k) 
                jshift=jshift0*k 
                if (lin.eq.1 .and. layout.eq.'linear') jshift=jshift0
                n=1+j+(jj-1)*jshift
                if (n.lt.1) n=n+nd
                mcon(k+1,n)=count
              enddo
              count=count+1
            endif  
          enddo  
        enddo  
      enddo

      goto 7
      write(*,*) 'conpos(m,n)'
      write(*,100) 0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
c 100  format(i5,17(i3))
      do j=-jmax,jmax
         n=1+j
         if (n.lt.1) n=n+nd
         write(*,100) j,(conpos(m,n),m=1,md)
      enddo
      write(*,*) 'icon(m,n)'
      write(*,100) 0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
c 100  format(i5,17(i3))
      do j=-jmax,jmax
         n=1+j
         if (n.lt.1) n=n+nd
         write(*,100) j,(icon(m,n),m=1,md)
      enddo
      write(*,*) 'mcon(m,n)'
      write(*,100) 0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
c 100  format(i5,17(i3))
      do j=-jmax,jmax
         n=1+j
         if (n.lt.1) n=n+nd
         write(*,100) j,(mcon(m,n),m=1,md)
      enddo

      write(*,*) 'ndom=',ndom
      do j=1,ndom
         write(*,*) j,' ncon(j)=',ncon(j),' scon(j)=',scon(j)
      enddo   
 7    continue

      do j=1,ndom
        do i=1,ncon(j)
          do k=1,scon(j)
           do m=1,md
            do n=1,nd
              if ((i.eq.mcon(m,n)).and.(k.eq.conpos(m,n)).and.
     .              (scon(j).eq.icon(m,n))) then
                 mmcon(j,k+(i-1)*scon(j))=m
                 nncon(j,k+(i-1)*scon(j))=n
              endif
            enddo
           enddo
          enddo
        enddo
      enddo   

c      do j=1,ndom
c        do k=1,ncon(j)*scon(j)
c          write(*,103) j,k,mmcon(j,k),nncon(j,k)
 103      format(i4,i4,' mmcon: ',i4,' nncon: ',i4)
c        enddo
c      enddo   

      return
      end