function ReadEarthFileSubset, dt,  tt_tomo, dd_tomo, file, FileRange, directory=directory
;+
; NAME:
;	ReadEarthFileSubset
; PURPOSE:
;	Read ea* file
; CALLING SEQUENCE:
;	A = ReadEarthFileSubset(dt, tt_tomo, dd_tomo, FileRange,directory=directory)
;
; OPTIONAL INPUTS:
;	dt				specify time interval to get the
;					desired record #
;	FileRange			array[2]; subset of file to pick for analyze
;					FileRange[0]: Starting point
;					FileRange[1]: End point
;	directory			Directory of the files to be compared, if
;					no directory is given, $DAT/nagoya/forecast
;					is the default directory
; OUTPUTS:
;	tt_tomo=tt_tomo		array[n]; type: time structure
;							times read from file
;	dd_tomo=dd_tomo		array[n,6]; type: float
;							density, velocity, radial magnetic field,
;							tangential magnetic field at times tt_tomo
; CALLS:
;	SetFileSpec, GetFileSpec, filepath, flt_read, TimeSet, tagarray
; PROCEDURE:
; MODIFICATION HISTORY:
;	NOV-1999, Paul Hick (UCSD)
;	DEC-2000, Kevin
;-
on_error, 2

; Do not modify the input argument file_in !!


bad = [-9999.999,-9999.999, -999.999, -999.999]

NOF = n_elements(FileRange)
if n_elements(dt) eq 0 then dt = 0

dt = round(dt*24/6.)
dtcenter = 80
dn = dt + dtcenter

if n_elements(directory) eq 0 then directory = $
	filepath(root=getenv('DAT'), subdir=['nagoya','slow','raw'], '')

wildcard = filepath(root=directory, 'ea*.*')
fileSet = file_search(wildcard, count=nfile)
if nfile eq 0 then message, 'no ea*.* files found in '+directory
  
if NOF ne 0 then begin
	FileNumPos = strlen(fileSet(0)) -  8
;	print, strmid(fileSet(1), FileNumPos, 8)

	index2 = 0
	index1 = 0
	ifile = 0
	while(ifile lt nfile) and (float(strmid(fileSet(ifile), FileNumPos, 8)) lt FileRange[0]) do begin
		index1 = ifile
		ifile = ifile + 1
	endwhile
	if (ifile eq nfile) and (float(strmid(fileSet(index1), FileNumPos, 8)) lt FileRange[0]) then begin
 		print, 'Invalid subset'
	endif else begin
		while(ifile lt nfile) and (float(strmid(fileSet(ifile), FileNumPos, 8)) lt FileRange[1]) do begin
			index2 = ifile
			print, fileSet[ifile]
			ifile = ifile  + 1
		endwhile
	endelse

	fileSet = extrac(fileSet, index1, index2 - index1) 

endif else	$
	fileSet = fileSet(sort(fileSet))

nfile = n_elements(fileSet)
file = fileSet[nfile-1]


dd_tomo = fltarr(nfile, 4)
tt_tomo = replicate(!TheTime,nfile)

for ifile=0, nfile-1 do begin
	stat = flt_read(fileSet[ifile],data,/silent)

	tt_data = TimeSet(yr=reform(data[0, *]), doy=reform(data[1, *]), hour=reform(data[2, *]))
	tt_tomo[ifile] = tt_data[dn]
	dd_tomo[ifile, 0] = data[7, dn]		; Velocity
	dd_tomo[ifile, 1] = data[6, dn]		; Density
	dd_tomo[ifile, 2] = data[8, dn]
	dd_tomo[ifile, 3] = data[9, dn]
endfor

message, /info, 'processed'+strcompress(nfile)+' ea*.* files in '+directory

for i=0,n_elements(bad)-1 do begin
	tmp = where(dd_tomo[*,i] eq bad[i])
	if tmp[0] ne -1 then dd_tomo[tmp,i] = BadValue(bad[i])
endfor

;good = where(dd_tomo gt 0)
;if good[0] eq -1 then message, 'no data'
;tt_tomo = tt_tomo[good]

;dd_tomo = dd_tomo[good, *]

return,  1  &  end