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resolveWavesHayashi

Reorder the complex coefficients returned by cfftf to resolve the progressive and retrogressive waves.

Available in version 5.1.0 and later.

Prototype

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/diagnostics_cam.ncl"

	function resolveWavesHayashi (
		x [2][*][*] : numeric,  
		window  [1] : integer,  
		spd     [1] : integer   
	)

	return_val  :  

Arguments

x

A three-dimensionsl array. The leftmost dimension contain the real and imaginary coefficients; the middle dimension refers to 'longitude'; and , the rightmost dimension refers to 'time'.

window

Number of days per season/segment.

spd

Samples per day: spd=1 for daily data; spd=2 for 12-hourly data; etc.

Return value

The return array will be two-dimensional. If the two rightmost dimensions of x are of sizes M and N, then the returned array will be of size (M+1,N+1). The '+1' comes from the 0-th wave and frequency.

Description

The input x is partitioned as follows:

  Create return array POWER(M+1,N+1) which contains the power spectrum.
  all the following assume indexing starting with 0
  In this array, the negative wavenumbers will be from pn=0 to M/2-1;
  The positive wavenumbers will be for pn=M/2+1 to M.
  Negative frequencies will be from pt=0 to N/2-1
  Positive frequencies will be from pt=N/2+1 to N  .
  Information about zonal mean will be for pn=M/2  .
  Information about time mean will be for pt=N/2  .
  Information about the Nyquist Frequency is at pt=0 and pt=N

See Also

wkSpaceTime, wkSpaceTime_cam

Examples

See Example 10 of the Madden-Julian Oscillation web page.