pro rdvfile,filename
@pltdat.h
;
; Open and read new vectors file:
;
if luvec ge 0 then free_lun,luvec
on_ioerror,bad
openr,luvec,filename,/get_lun
print,' '
print,'Opened file ',filename
;
;function gotoframe, lu,icur,iwant,flnm,frame
;   istat = gotoframe(ludat,ifileframe,iwant,flnm,frame) 
;
istat = gotoframe(luvec,0,vec.uvframes(0),filename,uframe)
if istat ne 0 then begin
  print,'>>> Error reading U-dat from file ',filename,' (frame number ',$
    vec.uvframes(0),')'
  return
endif
istat = gotoframe(luvec,vec.uvframes(0),vec.uvframes(1),filename,vframe)
if istat ne 0 then begin
  print,'>>> Error reading V-dat from file ',filename,' (frame number ',$
    vec.uvframes(1),')'
  return
endif
if uframe.nx ne vframe.nx or uframe.ny ne vframe.ny then begin
  print,' '
  print,'>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>'
  print,'WARNING: NX or NY dimensions of vector data are not equal:'
  print,'nx(U)=',uframe.nx,' ny(U)=',uframe.ny,' nx(V)=',vframe.nx,$
    ' ny(V)=',vframe.ny
  print,'This will cause problems very soon...
  print,'>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>'
  print,' '
endif
return
bad: print,'Error opening file ',filename
luvec = -1
return
end