pro ltf_plot, avg, var, favg, yfit, pmin, pmax, qplot, gainc
;
; procedure to PLOT light transfer for 512 CCD
;
;
!FANCY = 1
!XTITLE = 'Signal (DN)'
!YTITLE = '(Noise) !E2!N (DN)!E2!N'
!mtitle = ' '
SET_XY
!type = 16
;
valid=indgen( n_elements(avg) )
if (pmax ne 0.) then valid = where ((avg lt pmax) and (avg gt pmin))

pavg = avg(valid)
pvar = var(valid)
;!psym = 1		; + symbol
!psym = 3		; . symbol
plot, pavg, pvar

if (qplot eq 1) then begin
    !PSYM = 0
    OPLOT, favg, YFIT

    sout = STRING (gainc, "(' Gain Constant = ',F7.2,' e/DN')")
    plottime, 0.15, 0.70, sout, 0.8
END

return
end