pro zonalwvnall,un,nx,ny,nz,nwvn,uspc,uphs,uwv
;; zonal wavenumber analyzer at a given altitude and latitude base on zonalwvn.
;; Hanli Liu, 2/00

uspc = fltarr(nx,ny,nz)
uphs = uspc
;Mean flow and wave number nwvn components.  Add 1 to last dimension to get wavenumber to match index number
uwv = fltarr(nx,ny,nz,nwvn+1)

;Mask array

wvmask = fltarr(nx)

for j = 0,ny-1 do begin
    for k = 0,nz-1 do begin
        fftmp = fft(un(*,j,k))
        uspc(*,j,k) = abs(fftmp)*2
        uphs(*,j,k) = -atan(fftmp,/phase)/!DTOR
        fftmp1 = complexarr(nx)
        uwv(*,j,k,0) = float(fftmp1(0))
	
        FOR iwvn = 1, nwvn DO BEGIN

          wvmask[iwvn] = 1.
          wvmask[nx-iwvn] = 1.
; wave number iwvn
;print, 'j,k,iwvn,nx-iwvn,wvmask ',j,k,iwvn,nx-iwvn,wvmask
          fftmp1 = fftmp*wvmask
          uwv(*,j,k,iwvn) = float(fft(fftmp1,1))

          wvmask[iwvn] = 0.
          wvmask[nx-iwvn] = 0.
	  
        ENDFOR

     endfor
endfor
uspc(0,*,*)=uspc(0,*,*)/2.

return
end