source/cluster/wham/src-M-SAXS-homology/seq2chains.f

   1       subroutine seq2chains(nres,itype,nchain,chain_length,chain_border,
   2      &  ireschain)
   3 c
   4 c Split the total UNRES sequence, which has dummy residues separating
   5 c the chains, into separate chains. The length of  chain ichain is
   6 c contained in chain_length(ichain), the first and last non-dummy
   7 c residues are in chain_border(1,ichain) and chain_border(2,ichain),
   8 c respectively. The lengths pertain to non-dummy residues only.
   9 c
  10       implicit none
  11       include 'DIMENSIONS'
  12       integer nres,itype(nres),nchain,chain_length(nres),
  13      &  chain_border(2,nres),ireschain(nres)
  14       integer ii,ichain,i,j
  15       logical new_chain
  16       ichain=1
  17       new_chain=.true.
  18       chain_length(ichain)=0
  19       ii=1
  20       do while (ii.lt.nres)
  21         if (itype(ii).eq.ntyp1) then
  22           if (.not.new_chain) then
  23             new_chain=.true.
  24             chain_border(2,ichain)=ii-1
  25             ichain=ichain+1
  26             chain_border(1,ichain)=ii+1
  27             chain_length(ichain)=0
  28           endif
  29         else
  30           if (new_chain) then
  31             chain_border(1,ichain)=ii
  32             new_chain=.false.
  33           endif
  34           chain_length(ichain)=chain_length(ichain)+1
  35         endif
  36         ii=ii+1
  37       enddo
  38       if (itype(nres).eq.ntyp1) then
  39         ii=ii-1
  40       else
  41         chain_length(ichain)=chain_length(ichain)+1
  42       endif
  43       if (chain_length(ichain).gt.0) then
  44         chain_border(2,ichain)=ii
  45         nchain=ichain
  46       else
  47         nchain=ichain-1
  48       endif
  49       ireschain=0
  50       do i=1,nchain
  51         do j=chain_border(1,i),chain_border(2,i)
  52           ireschain(j)=i
  53         enddo
  54       enddo
  55       return
  56       end