pro markprep, rot1,rot2, nodelete=nodelete

@compile_opt.pro		; On error, return to caller

;+
; NAME:
;	MarkPrep
; PURPOSE:
;	Converts HAO MARK III synoptic map files (UNIX files) to VAX fixed
;	record binary files
; CATEGORY:
;	I/O
; CALLING SEQUENCE:
;	markprep [, first_rotation, last_rotation, /nodelete]
; INPUTS:
; OPTIONAL INPUT PARAMETERS:
;	first_rotation	# of first Carrington rotation to be processed
;	last_rotation	# of last rotation to be processed
;	/nodelete	the original HAO file is deleted after conversion to
;			VAX format UNLESS the /nodelete keyword is set
; CALLS:
;	SetFileSpec, GetFileSpec, do_file,  ieee_to_vax, bin_read
; PROCEDURE:
; >	If both arguments are omitted, user prompts will follow
; >	For each rotation 4 files are procesed: *e1.36, *e1.74, *w1.36, *w1.74.
; >	The VAX file is an unformatted file with fixed record lenght of 720
;	bytes (360 short integers; 180 long integers).
; >	The array read from the HAO file is a 360 x 181 short integer array.
; >	The array is flipped in the latitudinal direction by applying
;	a rotate(array,7). (This is the form in which the MARKIII synoptic
;	map program expects to find the array).
; MODIFICATION HISTORY:
;	MAR-1994, Paul Hick (UCSD)
;-

delete = 1-keyword_set(nodelete)

case n_params() of
1: rot2 = rot1
2:
else: message, 'Specify start and end rotation, or just a single rotation
endcase

postfix = ['E1.36','E1.74','W1.36','W1.74']

for i=rot1,rot2 do begin
	for j=0,3 do begin
		file = strcompress(i,/rem)+postfix(j)
		if bin_read(file,a,nx=360) then begin
			a = a[*,0:180]
			ieee_to_host, a
			a=rotate(a,7)

			infile = file

			SetFileSpec, file
			file = GetFileSpec(part='name')+strmid(GetFileSpec(part='type'),1)+'.MRK'

			message, /info, 'Creating '+file
			openw,/get_lun,iu, file,/fixed,2*360
			writeu,iu,a
			free_lun,iu

			if delete then stat = do_file(infile,/delete)
		endif
	endfor
endfor

return  &  end