pro accum, select = iselect, ltime=ltime, in_obs=obs, in_eobs=eobs, in_back=back, in_eback=eback, $ ;inputs
    live=live, obsi=obsi, eobsi=eobsi, backi=backi, ebacki=ebacki, convi=convi      
    
;Done automatically after select!
;Sum the intervals selected together
    nsel = n_elements(iselect(0,*))
    if n_elements(back) ne 0 then nbck = 1 else nbck=0  ;has background been passed?
    nchan = n_elements(obs(*,0))
    live = fltarr( nchan, nsel )
    obsi = fltarr( nchan, nsel)
    convi = obsi
    eobsi = obsi
    if nbck then begin
        backi= obsi
        ebacki= obsi
    endif

    for i=0, nsel-1 do begin
        wsel = indgen( iselect(1,i)-iselect(0,i)+1>1)+iselect(0,i)
        msel = n_elements(wsel)
        if msel gt 1 then begin
          live(*,i) = total( ltime(*,wsel),2)
          obsi(*,i) = f_div( total(  obs(*,wsel)*ltime(*,wsel),2) , live(*,i))
          eobsi(*,i) = f_div( total((eobs(*,wsel)*ltime(*,wsel))^2.,2)^0.5 , live(*,i) )
                  if nbck then begin
            backi(*,i) = f_div( total(  back(*,wsel)*ltime(*,wsel),2) , live(*,i) )
                    ebacki(*,i) = rebin(eback(*, wsel),nchan,1)
          endif

        endif else begin
          live(*,i) = ltime(*,wsel)
          obsi(*,i) = obs(*,wsel)
          eobsi(*,i)= eobs(*,wsel)
          if nbck then begin
            backi(*,i)= back(*,wsel)
            ebacki(*,i)=eback(*,wsel)
          endif
        endelse
        endfor

end