      subroutine ac_intj(nt,nbins,acorj,acintj)
c copyright, bernd berg, feb 14 2001.
c input:  jackknife array of autocorrelations acorj.
c output: jackknife array of integrated autocorrelation times acintj.
      include '../../libs/fortran/implicit.sta'
      include '../../libs/fortran/constants.par'
      dimension acorj(nbins,0:nt),acintj(nbins,0:nt)
      do ibins=1,nbins
      acintj(ibins,0)=one
        do it=1,nt
        acintj(ibins,it)=acintj(ibins,it-1)+two*acorj(ibins,it)
     &                                         /acorj(ibins,0)
        end do
      end do
      return
      end
