Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/~valenti/idl/wdech_raw.pro Дата изменения: Tue Jun 21 19:43:10 2011 Дата индексирования: Sat Mar 1 23:59:44 2014 Кодировка: Поисковые слова: comet tail

pro wdech_raw, ech, file
;Writes an IDL spectrum structure to a ".ech" format disk FITS file with
; binary table extensions. The FITS header is removed from the structure
; and written as the primary header of the disk file. No error checking
; is performed.
;
;Inputs:
; ECH (structure) echelle spectrum structure, which must contain a HEAD tag
; corresponding to a valid ".ech" format FITS header; all other fields in
; the structure are written to disk as binary table extension without
; modification.
; FILE (string) root name of a ".ech" disk file; an optional ".ech"
; extension may be included at the end of the root name; the specified
; disk file will either be created or **overwritten** with altered
; contents.
;
;Output:
; The specified disk file is created or modified.
;
;See also:
; modech, rdech, wdech
;
;History:
; 27-Jul-1998 Valenti Initial coding.

if n_params() lt 2 then begin
print, 'syntax: wdech_raw, ech, file (.ech assumed)'
return
endif

;Make sure input data are in a structure.
sz = size(ech) ;variable info block
if sz(sz(0)+1) ne 8 then begin ;true: not a structure
message, /cont, 'spectrum data must be a structure - aborting'
return
endif

;Make sure input structure contains header.
if not tag_exist(ech, 'HEAD') then begin ;true: no HEAD tag
message, /cont, 'spectrum structure does not contain HEAD tag - aborting'
return
endif

;If FRAME and UNITS tags exist, make sure they indicate raw structure data.
raw = 1 ;set raw flag
if tag_exist(ech, 'FRAME') then begin ;true: tag exists
if ech.frame ne 'raw' then raw = 0 ;true: trouble, clear flag
endif
if tag_exist(ech, 'UNITS') then begin ;true: tag exists
if ech.units ne 'raw' then raw = 0 ;true: trouble, clear flag
endif
if not raw then begin ;true: processed data
message, /cont, 'Data structure has been processed' $
+ ' - only raw data may be saved.'
message, /cont, 'Use "rdech, /raw" to obtain raw' $
+ ' data structures from disk.'
message, /cont, 'Then add or modify fields using' $
+ ' modech.'
message, /cont, 'Modified structure was not saved' $
+ ' to disk.'
return
endif

;Create a new structure with the HEAD, FRAME, and UNITS fields removed.
tags = tag_names(ech) ;list of tags
ntags = n_elements(tags) ;number of tags
icopy = where(tags ne 'HEAD' $
and tags ne 'FRAME' $
and tags ne 'UNITS', ncopy) ;find tags to copy
if ncopy le 0 then begin ;true: no spectrum data
message, /cont, 'structure does not contain spectrum data - aborting'
return
endif
j = icopy(0) ;index of first copy tag
newech = create_struct(tags(j), ech.(j)) ;initialize structure
for i=1, ncopy-1 do begin ;loop thru remaining tags
j = icopy(i) ;index of current tag
newech = create_struct(temporary(newech) $
,tags(j), ech.(j)) ;copy into new structure
endfor

;Make a copy ofthe header and remove certain cards.
head = ech.head
sxdelpar, head, 'SIMPLE'
sxdelpar, head, 'BITPIX'
sxdelpar, head, 'NAXIS'
sxdelpar, head, 'NAXIS1'
sxdelpar, head, 'NAXIS2'
sxdelpar, head, 'BSCALE'
sxdelpar, head, 'BZERO'

;Write header and data as disk FITS file with binary table extensions.
mwrfits, undefined, file, head, /create ;(re)create disk file
mwrfits, newech, file ;append binary table extension

end