pro pltlin
;
; Read ascii data file made by ../tigcmdif/pltutlin.f
;
;def_file = '/d/foster/tigcmdif/lunar.days6-12.dat'
;def_file = 'lunar.days6-12.fof2.dat'
def_file = 'lunar.days0-17.fof2.dat'
;
; Open data file:
;
nfiles = 0
nframes = 0
iframe = 0
nextfile:
print,' '
print,format="('Enter file name (stop to quit) [default=',a,']',$)",$
  def_file
flnm = ''
read,flnm
if flnm eq 'stop' then begin
  print,'bye'
  return
endif
if strlen(flnm) eq 0 then begin
  flnm = def_file
  print,'Using default file ',flnm
endif
if nfiles gt 0 then close,lu
openr,lu,flnm,/get_lun,error=err
if err ne 0 then begin
  print,'Error opening file ',flnm
  goto,nextfile
endif else print,'Opened file=',flnm,' (unit=',lu,')'
def_file = flnm
;
; Determine how many frames to plot from this file:
;
print,' '
print,format="('Enter number of frames for this file',$)"
nfr = ''
read,nfr
if strlen(nfr) eq 0 then begin
  print,'Will plot all frames in file'
  nframes = 999 
endif else begin
  reads,nfr,nframes
  print,'Will plot ',nframes,' frames from file'
endelse
iframe = 0
;
; Ask about making postscript:
;
print,' '
print,format="('Make postscript files? [n]',$)"
ps = '' & ips = 0
read,ps
if ps eq 'y' then begin
  ips = 1
  print,'Will make postscript files for each frame'
endif else print,'Will NOT make postscript files'
;
; Read and echo header info:
;
nextframe:
while (not eof(lu)) do begin
print,' '
histlab = ''
readf,lu,histlab
histlab = strtrim(histlab,2)
print,histlab
;
fieldlab = ''
readf,lu,fieldlab
fieldlab = strtrim(fieldlab,2)
print,fieldlab
;
framelab = ''
readf,lu,framelab
framelab = strtrim(framelab,2)
print,framelab
;
loclab = ''
readf,lu,loclab
loclab = strtrim(loclab,2)
print,loclab
;
xdatlab = ''
readf,lu,xdatlab
xdatlab = strtrim(xdatlab,2)
print,xdatlab
ydatlab = ''
readf,lu,ydatlab
ydatlab = strtrim(ydatlab,2)
print,ydatlab
;
; ntms = number of times (x-axis)
; ut(ntms) will be converted to days
;
ntms = 0
reads,ydatlab,ntms,format="(3x,i4)"
ut = fltarr(ntms)
readf,lu,ut
ut = ut/24.
dat = fltarr(ntms)
readf,lu,dat
rmin = min(dat,max=rmax)
title='DIFFERENCE FIELD:  ' + loclab + $
  string(rmin,rmax,format="('  MIN,MAX = ',g8.2,', ',g8.2)")
;plot,ut,dat,xtitle='MODEL DAY',ytitle='DIFF '+ fieldlab,title=title,/xstyle,$
;  xminor=12,xtick_get=xtics,ytick_get=ytics
plot,ut,dat,xtitle='MODEL DAY',ytitle='DIFF '+ fieldlab,title=title,/xstyle,$
  xminor=10,xtick_get=xtics,ytick_get=ytics
nytics = n_elements(ytics) & nxtics = n_elements(xtics)
for i=0,nxtics-1 do plots,[xtics(i),xtics(i)],[ytics(0),ytics(nytics-1)],$
  /linestyle
if rmin lt 0. and rmax gt 0. then plots,[ut(0),ut(ntms-1)],[0.,0.],$
  /linestyle
iframe = iframe+1
print,' '
if ips gt 0 then begin
  psfile = string(iframe,format="('fr',i3.3,'.ps')")
  print,'Making postscript file ',psfile,'...'
  save_dev = !d.name
  set_plot,'ps'
  device,filename=psfile,xsize=7.,ysize=6.,yoffset=4.,/inches,/portrait
; plot,ut,dat,xtitle='MODEL DAY',ytitle=fieldlab,title=title,/xstyle,$
;   xminor=12,xtick_get=xtics,ytick_get=ytics,charsize=.9
  plot,ut,dat,xtitle='MODEL DAY',ytitle=fieldlab,title=title,/xstyle,$
    xminor=10,xtick_get=xtics,ytick_get=ytics,charsize=.9
  for i=0,nxtics-1 do plots,[xtics(i),xtics(i)],[ytics(0),ytics(nytics-1)],$
    /linestyle
  if rmin lt 0. and rmax gt 0. then plots,[xtics(0),xtics(nxtics-1)],[0.,0.],$
    /linestyle
  device,/close
  set_plot,save_dev
endif 
print,iframe,format=$
  "('Completed frame ',i3,' (hit return to continue or stop to quit)',$)"
ans = ''
read,ans
if ans eq 'stop' then goto,nextfile
if nframes lt 999 then begin
  if iframe lt nframes then goto,nextframe else goto,nextfile
endif
goto,nextframe
endwhile
goto,nextfile
return
end