[ncl-talk] problem with specx_anal (ntim x nlat x nlon)

[Lyndz]

Dear NCL-experts,

I would like to do a spectral analysis on a *ntim x nlat x lon* data as
indicated in example 3 from this page:
https://www.ncl.ucar.edu/Document/Functions/Built-in/specx_anal.shtml

*Specifically, I would like to get the mean spectra so that the final
output will have meanspectra x lat x lon*


*So far, I have the following:*

  ufile  = addfile("anom_rain_sm_1951-2007_jjas.nc","r")       ; open
netcdf file
  rain = ufile->rAnom_sm(:,:,:)

  printVarSummary(rain)            ;[time | 6954] x [latitude | 220] x
[longitude | 220]

  d   = 0
  sm  = 1         ; periodogram
  pct = 0.10


;************************************************
; calculate mean spectrum spectrum and lag1 auto cor
;************************************************

ntim = 6954
nlat = 220
nlon = 220

nseg = 49
nlen  = ntim/nseg

spcavg = new (ntim/141, typeof(rain))
printVarSummary(spcavg)
spcavg = new ( ntim/2, typeof(rain))
spcavg = 0.0
r1zsum = 0.0

     do n=0,nseg-1
      dof    =
specx_anal(rain(latitude|nl:nl,longitude|ml:ml,time|:),d,sm,pct)      ;
current segment spc
      spcavg = spcavg + dof at spcx                ; sum spc of each segment
      r1     = dof at xlag1                        ; extract segment lag-1
      r1zsum = r1zsum  + 0.5*(log((1+r1)/(1-r1)) ; sum the Fischer Z
    end do
   r1z  = r1zsum/nseg                           ; average r1z
   r1   = (exp(2*r1z)-1)/(exp(2*r1z)+1)            ; transform back
                                                                        ;
this is the mean r1
   spcavg  = spcavg/nseg                                ; average spectrum

*Questions:*
 (1) How do I loop this across all the gridpoints? I am having a problem
with the looping and saving the spectra in spcavg(ntim,nlat,nlon). Any
suggestions on how to do this in NCL? The example in the page is incomplete.


I'll appreciate any help on this.


-Lyndz
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