anchor.diff:              !
               eta2 = 1.0_rk-eta1
               !
  +            dnu_half = dfreq*0.5_rk
  +            !
               !eta2 = 0.32460_rk-0.61825_rk*d+0.17681_rk*d**2+0.12109_rk*d**3
               !
               !$omp parallel do private(ipoint,dfreq_,xp,xm,de,intens1,intens2) shared(intens) schedule(dynamic)
  
positive.code:             !
              eta2 = 1.0_rk - eta1
              !
              !$omp parallel do private(ipoint,dfreq_,xp,xm,de,intens1,intens2) shared(intens) schedule(dynamic)
              do ipoint=ib,ie
                 !
                 dfreq_=freq(ipoint)-tranfreq
                 !
                 xp = atan((dfreq_+dfreq)/halfwidth)
                 xm = atan(dfreq_/halfwidth)
                 !
                 de = (xp)-(xm)
                 !
  
negative.code:           if (tranfreq<small_) cycle
            !
            halfwidth=dpwcoef*tranfreq
            !
          endif
          !
          if (offset<0) offset = ioffset*halfwidth
  