function eit_gt_wavelnth, header, image_no=image_no, debug=debug
;+
; Name:
; eit_gt_wave
;
; Purpose:
; Return the wavelength of a 2- or 3-D index structure or
; FITS header.
;
; Input Parameters:
; header = FITS header or EIT index structure for image
;
; Input Keywords:
; image_no = Image number from within above header
;
; Output:
; wavelength of chosen image
;
; Calling Sequence:
; wave = eit_gt_wavelnth(fits_header)
; wave = eit_gt_wavelnth(fits_header,image_no=7)
; wave = eit_gt_wavelnth(index [,image_no=4])
;
; Running Commentary:
; Another workaround for fits keywords disguised as comments.
;
; History:
; 3-November-96 - (BNH) - Written
;-
if (n_elements(header) eq 0) then begin
message, /info, 'No index/fits header supplied!'
return, -1
endif
case gt_tagval(header, /naxis) of
2: return, gt_tagval(header, /wavelnth)
3: case data_chk(header, /type) of
7: return, eit_fxpar(header, 'WAVELNTH', image_no=image_no)
8: return, gt_tagval(index(image_no), /wavelnth)
else: begin
message, /info, "Passed value is not a valid header or index structure."
return, -1
end
endcase
endcase
end
Last revised: - Wed May 9 21:45:19 2007- F. Auchère