; =================================================;
; stream_2.ncl
; =================================================;
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"   
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"   
; =================================================;
begin
  f = addfile("uvt.nc","r")
  u    = f->U(0,0,:,:)    ; read in example data [2D only here]
  v    = f->V(0,0,:,:)
; =================================================;
; create plots
; =================================================;
  wks  = gsn_open_wks("ps","stream")               ; open a Graphic wkStation
  res  = True                                       ; plot mods desired
  res@tiMainString       = "Streamlines"            ; title

  res@stArrowLengthF     = 0.004                    ; size of the arrows.
  res@stMinArrowSpacingF = 0.004                    ; arrow spacing.
  res@stArrowStride      = 3                        ; arrows start every third

  plot = gsn_csm_streamline_map_ce(wks,u,v,res)
end