implicit real*8 (a-h,o-z)
      include 'DIMENSIONS'
      include 'COMMON.CHAIN'
      include 'COMMON.INTERACT'
      include 'COMMON.SBRIDGE'
      include 'COMMON.DISTFIT'
      real*4 coord(3,2*maxres)
      real*4 prec,time,potE,uconst,t_bath,qfrag(100)
      real*8 etot
      character*80 arg,seqfile,pdbfile
      character*3 sequenc(maxres)
      character*50 tytul
      character*8 onethree,cfreq
      character*8 ucase
      external ucase
      logical oneletter
      integer rescode
      external rescode
      logical iblnk
      external iblnk
      double precision cm(3)
      
      ifreq=1
      is=1
      ie=1000000000
      if (iargc().lt.3) then
        print '(2a)',
     &    "Usage: xdrf2pdb one/three seqfile cxfile [freq]",
     &    " [start] [end] [pdbfile]"
        stop
      endif
      call getarg(1,onethree)
      onethree = ucase(onethree)
      if (onethree.eq.'ONE') then
        oneletter = .true.
      else if (onethree.eq.'THREE') then
        oneletter = .false.
      else
        print *,"ONE or THREE must be specified"
      endif
      call getarg(2,seqfile)
      open (1,file=seqfile,status='old')
      if (oneletter) then
        read(1,'(80a1)',end=10,err=10) (sequenc(i)(1:1),i=1,maxres)
   10   continue
        nres=i
        i=0
        do while (.not.iblnk(sequenc(i+1)(1:1)))
          i=i+1
        enddo 
        nres=i
        do i=1,nres
          itype(i)=rescode(i,sequenc(i),1)
        enddo
      else
        read(1,'(20(a3,1x))',end=11,err=11) (sequenc(i),i=1,maxres)
   11   continue
        nres=i
        i=0
        do while (.not.iblnk(sequenc(i+1)(1:1)))
          i=i+1
        enddo 
        nres=i
        do i=1,nres
          itype(i)=rescode(i,sequenc(i),0)
        enddo
      endif
      call getarg(3,arg)
      iext = index(arg,'.cx') - 1
      if (iext.lt.0) then
        print *,"Error - not a cx file"
        stop
      endif
      if (iargc().gt.3) then
        call getarg(4,cfreq)
        read (cfreq,*) ifreq
      endif
      if (iargc().gt.4) then
        call getarg(5,cfreq)
        read (cfreq,*) is
      endif
      if (iargc().gt.5) then
        call getarg(6,cfreq)
        read (cfreq,*) ie
      endif
      if (iargc().gt.6) then
        call getarg(7,pdbfile)
      else
        pdbfile=arg(:iext)//'.pdb'
      endif
      open(9,file=pdbfile)
      nnt = 1
      if (itype(1).eq.21) nnt = 2
      nct=nres
      if (itype(nres).eq.21) nct = nres-1
      print *,"nnt",nnt," nct",nct
      print *,"file",arg
      do i=nnt,nct
        if (itype(i).ne.20) then
          itel(i)=1
        else
          itel(i)=2
        endif 
      enddo
      call xdrfopen(ixdrf,arg, "r", iret)
      if (iret.eq.0) stop
c      print *,"iret",iret
c      print *,"is",is," ie",ie
      kk = 0
      do while(is.eq.0 .or. kk.lt.ie) 
       call xdrffloat(ixdrf, time, iret)
c       print *,"time",time," iret",iret
       if(iret.eq.0) exit
       kk = kk + 1
       call xdrffloat(ixdrf, potE, iret)
       call xdrffloat(ixdrf, uconst, iret)
c       print *,"potE",potE," uconst",uconst
#ifdef NEWUNRES
       call xdrffloat(ixdrf, uconst_back, iret)
c       print *,"uconst_back",uconst_back
#endif
       call xdrffloat(ixdrf, t_bath, iret)
c       print *,"t_bath",t_bath
       call xdrfint(ixdrf, nss, iret) 
       do j=1,nss
        call xdrfint(ixdrf, ihpb(j), iret)
        call xdrfint(ixdrf, jhpb(j), iret)
       enddo
c       print *,"nss",nss
c       print *,"   ",(ihpb(j),"-",jhpb(j),j=1,nss)
       call xdrfint(ixdrf, nfrag, iret)
       do i=1,nfrag
        call xdrffloat(ixdrf, qfrag(i), iret)
       enddo
c       print *,"nfrag",nfrag
       prec=10000.0

       isize=0
       call xdrf3dfcoord(ixdrf, coord, isize, prec, iret)


c       write (*,'(e15.8,2e15.5,f12.5,$)') time,potE,uconst,t_bath
c       write (*,'(i4,$)') nss,(ihpb(j),jhpb(j),j=1,nss)
c       write (*,'(i4,20f7.4)') nfrag,(qfrag(i),i=1,nfrag)
c       write (*,'(8f10.5)') ((coord(k,j),k=1,3),j=1,isize)
       if (kk.ge.is .and. mod(kk,ifreq).eq.0) then
         if (isize .ne. nres+nct-nnt+1) then
           print *,"Error: inconsistent sizes",isize,nres+nct-nnt+1
         endif
         do i=1,nres
           do j=1,3
             c(j,i)=coord(j,i)
           enddo
         enddo
         ii = 0
         do i=nnt,nct
           ii = ii + 1 
           do j=1,3
             c(j,i+nres)=coord(j,ii+nres)
           enddo
         enddo
c Calculate the CM
         do j=1,3
           cm(j)=0.0d0
           do i=1,nres
             cm(j)=cm(j)+c(j,i)
           enddo
           cm(j)=cm(j)/nres
         enddo
         do i=1,nres
           do j=1,3
             c(j,i)=c(j,i)-cm(j)
             c(j,i+nres)=c(j,i+nres)-cm(j)
           enddo
         enddo
         etot=potE
         write (tytul,'(a,i6)') "Structure",kk
#ifdef SECONDARY
         call secondary2(.false.)
#endif
         call pdbout(etot,tytul,9)
       endif
      enddo
     
      end