PRO it_pp_wopt_02, tfile, ofile=ofile

;; Compares input refrac and occ(wopt(refrac)), assuming the former
;; is in ofile and the latter is in tfile.
;;
;; INPUT:
;;
;; KEYWORDS:
;;
;;; OUTPUT:
;;    error            1 [error] 0 [all fine]
;;

;; file settings
if n_elements(ofile) eq 0 then ofile = '../data/ropp_pp_wopt_tool.nc'  ;; observations
if n_elements(tfile) eq 0 then tfile = 'ropp_pp_wopt_tool_out.nc'      ;; output

;; read the original file

print,'Reading original file '+ofile
id = ncdf_open(ofile)

; Level 2a

var = 'alt_refrac' & ncdf_getvar, id, var, oalt_refrac, error=error
if error then print,'IDL it_wopt_02 Error: (1) Variable not found: '+var

var = 'refrac' & ncdf_getvar, id, var, orefrac, error=error
if error then print,'IDL it_wopt_02 Error: (2) Variable not found: '+var

ncdf_close, id


;; read the output file

print,'Reading output file '+tfile
id = ncdf_open(tfile)

; Level 2a

var = 'alt_refrac' & ncdf_getvar, id, var, talt_refrac, error=error
if error then print,'IDL it_wopt_02 Error: (1) Variable not found: '+var

var = 'refrac' & ncdf_getvar, id, var, trefrac, error=error
if error then print,'IDL it_wopt_02 Error: (2) Variable not found: '+var

ncdf_close, id



ifail=0
no2a=n_elements(oalt_refrac)
nt2a=n_elements(talt_refrac)

print,'No. Level 2a levels:',no2a,nt2a

;;; Interpolate data onto common levels
grid2a  = min(oalt_refrac)+findgen(1501)*(1.0*(max(oalt_refrac) - min(oalt_refrac)))/1500.0

trefrac      = interpol(trefrac, talt_refrac, grid2a)
talt_refrac  = interpol(talt_refrac, talt_refrac, grid2a)

orefrac      = interpol(orefrac, oalt_refrac, grid2a)
oalt_refrac  = interpol(oalt_refrac, oalt_refrac, grid2a)


;;; Compute maximum differences between data

diff = max( (oalt_refrac - talt_refrac) )
if ( diff gt 0.05 ) then begin
print, 'alt_refracs differ by ', diff, ' m - TEST FAILED'
ifail = 1
endif else begin
print, 'alt_refracs differ by ', diff, ' m - TEST PASSED'
endelse

diff = max( (orefrac - trefrac))
if ( diff gt 0.05) then begin
print, 'refracs differ by ', diff, ' N_units - TEST FAILED'
ifail = 1
endif else begin
print, 'refracs differ by ', diff, ' N-units - TEST PASSED'
endelse  

jpgfile = 'ropp_pp_comp.jpg'
resolution= [750, 1000]
open_jpgfile, jpgfile, resolution, thisDevice
!P.multi=[0,1,1]


; Plot refracs and the diff
!p.region = [0, 0, 0.95, 0.925]
plot, trefrac, (grid2a-min(grid2a)), /nodata, xrange=[1.e-4, 1.e3]*0.5, yrange=[0.0, 9e4], ystyle=1, xlog=1, ytitle="alt refrac (m)", xtitle="refrac (N-units)", xstyle=9, $
      tit='Ref file = '+ofile+'!CTest file = '+tfile+'!C!C'

oplot, orefrac, (grid2a-min(grid2a))
oplot, trefrac(25*indgen(60)), ((grid2a-min(grid2a)))(25*indgen(60)), psym=1
oplot, [1, 5], [8.5e4, 8.5e4], line=0  &  xyouts, 10, 8.5e4, /data, 'ref'
oplot, [1, 5], [8.0e4, 8.0e4], psym=1  &  xyouts, 10, 8.0e4, /data, 'test'
oplot, [1, 5], [7.5e4, 7.5e4], line=2  &  xyouts, 10, 7.5e4, /data, 'test-ref'
                                          xyouts, 10, 7.25e4, /data, '('+string(min(trefrac - orefrac),'(f7.1)')+' to '+string(max(trefrac - orefrac),'(f7.1)')+')

axis, xlog=0, xaxis=1, xrange=[-1, 1]*10, xstyle=1, xtit="refrac difference (N-units)", /save
oplot, (trefrac - orefrac)*0, [0, 1]*1e6, line=0
oplot, (trefrac - orefrac), (grid2a-min(grid2a)), line=2

close_jpgfile, jpgfile, resolution, thisDevice



if(ifail eq 1)then print, 'At least one test failed.....TEST FAILED!'
if(ifail eq 0)then print, 'All tests successful.....TEST PASSED!'




end