begin

  a = addfile("may_hgt-hgt_1979-1995_850hPa.nc","r")
  b = addfile("../../winds/uwnd/1979-1995/regpval_uwnd_1979-1995.nc","r")  
  c = addfile("../../winds/vwnd/1979-1995/regpval_vwnd_1979-1995.nc","r")
;************************************************
; read in data
;************************************************
  printVarSummary(a)
  printVarSummary(b)
  printVarSummary(c)
  t = a->regslope(:,:)
  u = b->regpval(:,:)
  v = c->regpval(:,:)   
                               
;************************************************
; create plot
;************************************************
  wks = gsn_open_wks("png","proj")                ; send graphics to PNG file
       
  res                   = True      
  res@gsnFrame          = False                   ;-- don't advance the frame
        
  res@cnLevelSelectionMode = "ManualLevels"      
  res@cnMinLevelValF    = -5.00      
  res@cnMaxLevelValF    = 5.00      
  res@cnLevelSpacingF   = 0.5      
      
  res@mpProjection      = "Orthographic"          ; choose projection
  res@mpCenterLonF      = 122.                    ; choose center lon
  res@mpCenterLatF      = 45.                     ; choose center lat
  res@mpPerimOn         = False                   ; turn off box around plo
  res@mpDataBaseVersion = "MediumRes"      
  res@mpOutlineOn       = True      
      
  res@cnFillOn          = True                    ; color plot desired
  res@cnFillPalette     = "BlueDarkRed18"           ; select color map
  res@cnLineLabelsOn    = False                   ; turn off contour line labels
  res@cnLinesOn         = False                   ; turn off contour lines
  res@cnFillDrawOrder   = "PreDraw" 
  res@mpGridAndLimbOn   = True               ; turn on lat/lon grid lines
  res@mpGridMaskMode    = "MaskNotOcean"     ; don't draw over land or
  res@mpFillOn = False                                                ; inland water bodies

;  res@lbLabelFontHeightF  = 0.015                 ; label bar font height
  res@gsnLeftString = ""
  res@gsnRightString = ""
  res@tiMainString       = "Regressed Rainfall-HGT(850hPa)"   ; add a title
;  res@tiMainFontHeightF  = .018                   ; font height

  plot = gsn_csm_contour_map(wks,t,res)

;;************************************************************
;;Add shapefiles
;;************************************************************ 
    res@vcGlyphStyle               = "LineArrow"
    res@vcLineArrowThicknessF      = 1.0
    res@vcLineArrowColor           = "black"

    res@vcMinDistanceF             = 0.01
    res@vcLineArrowHeadMaxSizeF    = 0.025
    res@vcRefLengthF               = 0.0250
    res@vcRefAnnoOrthogonalPosF   = -1.0 
    res@vcRefAnnoArrowLineColor   = "black"
    res@vcRefMagnitudeF           = 1.5  
    res@vcVectorDrawOrder = "PostDraw" 
  res@gsnDraw = False
  res@gsnFrame = False
  vector=gsn_csm_vector_scalar(wks,u,v,t,res)  
  overlay(plot,vector)
  draw(plot)
  frame(wks)
end