begin

;
; Create some data for the contour plot.
;
  M=25
  N=25
 
  T = new((/N,M/),float)
 
  jspn = ispan(-M/2,M/2,1)^2
  ispn = ispan(-N/2,N/2,1)^2
  do i = 0, dimsizes(ispn)-1
      T(i,:) = ispn(i) + jspn
  end do
  T = 100.0 - sqrt(8^2 * T)

;
; Create an X workstation.
;
  wid = create "wks" xWorkstationClass defaultapp end create

;
; Create a data object.
;
  dataid = create "data" scalarFieldClass defaultapp
    "sfDataArray" : T
  end create

;
; Create and draw a MapPlot object.
;
  mpid = create "MapPlot" mapPlotClass wid end create

  draw(mpid)         ; Draw map plot.

;
; Retrieve the viewport coordinates used in the map plot so they
; can be used in the contour plot.
;
  getvalues mpid
    "vpXF"       : xpos
    "vpYF"       : ypos
    "vpWidthF"   : width
    "vpHeightF"  : height
  end getvalues

;
; Create a ContourPlot object using the same viewport coordinates as
; the map plot.
;
  cnid = create "ContourPlot" contourPlotClass wid
    "vpXF"       : xpos
    "vpYF"       : ypos
    "vpWidthF"   : width
    "vpHeightF"  : height

    "cnScalarFieldData" : dataid
  end create

  draw(cnid)   ; Draw the contour plot.

  frame(wid)   ; Advance frame.
end