subroutine dat_2t
c	-----------------

	external dat_2t_desc
!	external dat_2t_high ! this line for raw data files only
	external dat_2t_read

	integer dtype/0/

	call dat_init_desc(dtype, dat_2t_desc)
	call dat_init_read(dtype, dat_2t_read)
	end


	subroutine dat_2t_desc(text)
!	----------------------------
	character*(*) text  ! (out) description

!             type    description
!             ----------------------------------
	text='2T      2T format (LLB Saclay)'
	end


	subroutine dat_2t_opts
!	----------------------
	print '(x,a)'
	1,'x: x-axis, y: y-axis'
	end


	subroutine dat_2t_read
	1 (lun, forced, nread, putval, nmax, xx, yy, ss, ww)
!	----------------------------------------------------
	implicit none

	integer lun	! (in) logical unit number (file will be closed if successful)
	integer forced	! 0: read only if type is sure; 1: forced read
	integer nread	! (out) >=0: = number of points read, file closed
	                !       -1: not correct type, file rewinded
	                !       -2: correct type, but unreadable, file rewinded
	external putval ! (in) subroutine to put name/value pairs.
	                ! for numeric data:     call putval('name', value)   ! value must be real
			! for character data:   call putval('name=text', 0.0)
	integer nmax    ! max. number of points
	real xx(*)	! x-values
	real yy(*)	! y-values
	real ss(*)	! sigma
	real ww(*)	! weights  (original monitor)

! local
	integer mcol
	parameter (mcol=32)

	character header*1024
	character line*1024, xaxis*8, yaxis*8, name*8, col1*8
	real values(32), s, y, ymon
	real tt, tm, ts, td
	integer i,j,l,ncol,ccol,xcol,tcol


	nread=0
	read(lun,'(a)',err=98,end=98) header
	if (forced .le. 0) then
	  if (header(1:11) .ne. '#  qh') goto 100
	endif
	header(1:1)=' '
	read(lun,'(a)',err=98,end=98) line
	if (line(1:1) .ne. '#') goto 100
	line(1:1)=' '

        xaxis=' '
        yaxis=' '

        call dat_start_options
        call dat_str_option('x', xaxis)
        call dat_str_option('y', yaxis)

        call str_upcase(xaxis, xaxis)
        call str_upcase(yaxis, yaxis)

	call putval('Instrument=2T',0.0)

	call dat_group(2, putval)
	do i=1,mcol
	  values(i)=0.0
	enddo
	ncol=0
	i=1
	read(line, *, err=15,end=15) values
15	call str_get_elem(header, i, name)
	if (name .ne. ' ') then
	  ncol=ncol+1
	  if (name .eq. 'm') then
	    name='Monitor'
	    ymon=values(ncol)
	    call putval('Preset=m', 0.0)
	  else if (name .eq. 't') then
	    name='Monitor'
	    ymon=values(ncol)
	    call putval('Preset=t', 0.0)
	  endif
	  call putval(name, values(ncol))
	  goto 15
	endif

	read(lun, '(a)') line
	if (line(1:1) .ne. '#') goto 100
	read(lun, '(a)') line
	if (line(1:1) .ne. '#') goto 100
	line(1:1)=' '

12	i=1
	line(len(line):len(line))=' '
	ncol=0
	ccol=0
	xcol=0
	tcol=0
	col1=' '
31	do while (line(i:i) .eq. ' ')
	  i=i+1
	  if (i .gt. len(line)) goto 39
	enddo
	l=i
	do while (line(i:i) .ne. ' ')
	  i=i+1
	enddo
	ncol=ncol+1
	if (ncol .eq. 1) col1=line(l:i)
	if (line(l:i) .eq. yaxis .or. yaxis .eq. ' '
	1    .and. line(l:i) .eq. 'comptage') ccol=ncol
	if (line(l:i) .eq. xaxis) xcol=ncol
        if (line(l:i) .eq. 'K') tcol=ncol
	goto 31

39	if (yaxis .eq. ' ') yaxis='comptage'
	if (ccol .eq. 0) then
	  print *,'no values found for ',yaxis
	  goto 99
	endif
	if (xcol .eq. 0) then
	  if (xaxis .ne. ' ') then
	    print *,'no values found for ',xaxis,', take ',col1
	  endif
	  xcol=1
	  xaxis=col1
	endif

	call dat_group(2, putval)
	call putval('XAxis='//xaxis, 0.0)
	call putval('YAxis='//yaxis, 0.0)
	call dat_group(1, putval)

	l=min(mcol,max(xcol,ccol,tcol))
	tm=0
	ts=0

4	read(lun,*,err=19,end=9) (values(j),j=1,l)
	if (nread .ge. nmax) goto 29
	y=values(ccol)
	if (y .gt. 0) then
	  s=sqrt(y)				! statistical error of detector
	else
	  s=1
	endif
	nread=nread+1
	xx(nread)=values(xcol)
	yy(nread)=y
	ss(nread)=s
	ww(nread)=ymon
	if (tcol .ne. 0) then
	  tt=values(tcol)
	  td=(tt-tm)/nread
	  tm=tm+td                             ! mean temp.
	  ts=ts+(tt-tm)**2+td*td*(nread-1)        ! sum of (temp(i)-mean)**2
	endif
	goto 4

9	close(lun)
	call putval('Monitor', ymon)
	if (tcol .ne. 0) then
	  call putval('Temp', tm)
	  if (nread .gt. 1) call putval('dTemp', sqrt(ts/(nread-1)))
	endif
	return

19	print *,'DAT_2T: error at point ',nread
	goto 4
29	print *,'DAT_2T: too many points'
	goto 100
98	if (forced .le. 0) goto 100
99	print *,'DAT_2T: error during read'
	rewind lun
	nread=-2
	return
100	nread=-1
	rewind lun
	end