PRO dustem_old2new_ext_format, dir=dir,file=file

;+
; NAME:
;    dustem_old2new_ext_format
;
; PURPOSE:
;    Converts an extinction curve in pre-4.3 DustEMWrap format into
;    the new format. 
;
; CATEGORY:
;    DustEMWrap, Low-Level, Distributed, User-convenience
;
; CALLING SEQUENCE:
;    
;
; INPUTS:
;    filter  = Filter name
;
; OPTIONAL INPUT PARAMETERS:
;    None
;
; OUTPUTS:
;    wave = reference wavelength (microns)
;
; OPTIONAL OUTPUT PARAMETERS:
;    None
;
; ACCEPTED KEY-WORDS:
;    help      = If set, print this help
;
; COMMON BLOCKS:
;    None
;
; SIDE EFFECTS:
;    Reads instrument_description.xcat at each call. Not optimal.
;
; RESTRICTIONS:
;    The DustEMWrap IDL code must be installed
;
; PROCEDURE:
;    None
;
; EXAMPLES
;    print,dustem_filter2wav(['IRAS1','MIPS3'])
;
; MODIFICATION HISTORY:
;    Written by J.-Ph. Bernard
;    Evolution details on the DustEMWrap gitlab.
;    See http://dustemwrap.irap.omp.eu/ for FAQ and help.  
;-

;NB: file should be the string of the old xcat file 

dustem_init

use_dir=!dustem_wrap_soft_dir+'/Data/EXAMPLE_OBSDATA/'
if keyword_set(dir) then use_dir=dir

file=dir+file

str='cp '+file+' '+file+'.old'
spawn,str

old_ext=read_xcat(file,/silent,comments=old_comments)
Next=n_elements(old_ext)

new_ext=dustem_initialize_ext(Next,comments=new_comments,help=help)
comments=['Written by dustem_old2new_ext_format.pro on '+systime(0),old_comments,new_comments]

new_ext.instru=old_ext.instru
new_ext.filter=old_ext.filter
new_ext.wave=old_ext.wave
new_ext.EXT_I=old_ext.spec
new_ext.sigextII=(old_ext.error)^2

write_xcat,new_ext,file,comments=comments

END