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ShadeCOI

Adds the cone of influence as a shaded polygon.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"      ; These four libraries are automatically
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"       ; loaded from NCL V6.4.0 onward.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"   ; No need for user to explicitly load.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"

	function ShadeCOI (
		wks   : graphic,  
		plot  : graphic,  
		w     : numeric,  
		time  : numeric,  
		res   : logical   
	)

	return_val [1] :  graphic

Arguments

wks

A Workstation identifier. The identifier is one returned either from calling gsn_open_wks or calling create to create a Workstation object.

plot

A plot to add the cone of influence polygon to. It can be an identifier created by using one of the many gsn functions, or by calling create to create a View object.

w

The data array (returned from the wavelet function); it must contain a "coi" attribute.

time

The time values corresponding with the coi values.

res

Optional list of GraphicStyle resources (for polygon fill).

Return value

plot will be returned with the cone of influence shaded.

Description

This function adds the cone of influence (returned from the wavelet function) as a shaded polygon. To control how the polygon is shaded, you can set res to True and set res@gsFillIndex resource to the desired fill pattern.

Examples

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" 
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" 
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"

begin
  f      = addfile ("/fs/cgd/home0/shea/ncld/test/sst_nino3.nc", "r")
  x      = f->SST
  N      = dimsizes(x)   ; number of elements [here 504]

  mother = 0             ; Morlet wavelet
  param  = 6.0           ; common for Morlet
  dt     = 0.25          
  s0     = 0.25
  dj     = 0.25          ; 4 sub-octaves per octave
  jtot   = 44            ; =subScale*11
  npad   = 1024          ; pad with extra zeros
  nadof  = new( 2,float) ; ignored

  noise  = 1             ; test vs red noise
  siglvl = 0.05
  isigtest= 0           

  w      = wavelet (x,mother,dt,param,s0,dj,jtot,npad \
                     ,noise,isigtest,siglvl,nadof)

                           ; create coordinate arrays for plot
  power            = onedtond( w@power, (/jtot,N/) )
  power!0          = "period"                        ; Y axis
  power&period     = w@period
  power!1          = "time"                          ; X axis
  power&time       = x&time
  power@long_name  = "Power Spectrum"
  power@units      = "C^2/unit-freq"

  wks = gsn_open_wks("ps","wavelet")
  res                     = True
  res@cnFillOn            = True
  res@trYReverse          = True
  res@gsnSpreadColors     = True
  res@gsnDraw = False
  res@gsnFrame = False
  plot = gsn_csm_contour(wks,power({0:64},:),res)    
  plot = ShadeCOI(wks,plot,w,x&time,False)
  draw(plot)
  frame(wks)
end