procedure writespec
#  Write a disk file containing 
#   [channel number]  [frequency offset]  [velocity]  [temperature]
#  for each channel of a spectrum.  
#  Usage notes:
#  1.  The spectrum is assumed to be in Array 0, i.e., the spectrum
#      displayed on the screen.
#  2.  The user is prompted for the output file name.  
#  3.  To drop channels from the beginning or end of the spectrum,
#      set values for BDROP or EDROP before executing the procedure.
#  4.  The velocity scale is assumed to be nonrelativistic.
#  PRJ  26 Jan 94
#
scalar unit, npts, cenchan, delfreq, start, stop, i
scalar ncount, freq, vel0, vel, delv, tr
string*16 filnam
#
print 'Enter the name of the output file: '
read filnam
unit = fopen(filnam, rw+rew+unk)
npts = h0(noint)
cenchan = h0(refpt)
delfreq = h0(freqres)
vel0 = h0(velocity)
delv = h0(deltax)
#
ncount = 0
start = bdrop + 1
stop = npts - edrop
for i = start to stop 
   freq = delfreq * (i - cenchan)
   vel = vel0 + delv * (i - cenchan)
   tr = d0(i)
   fprint (unit, '(1x, i5, 2x, f10.4, 1x, f11.4, 1x, f9.5)') i, freq, vel, tr
   ncount = ncount + 1
end
fclose(unit)
#
print ' '
print ncount ' data channels have been written to file: ', filnam
print ' '
return
finish