;-----------------------------------------------------------------
; entalpani.pro
;
; written by Andreas Reigber
;------------------------------------------------------------------
; Calculates the entropy, the anisotropy and alpha maps. As input
; it takes the array of coherency matrices.
; Attention: Coherency matrix means Pauli-base. If this is not the
; case, the results will be wrong.
; 
; Usage:
; res = entalpani(cov)
;     cov : Complex array containing the coherence matrices of the 
;           whole polarimetric image, interlaced in the 3rd and 4th
;           dimension, i.e. array size (xdim,ydim,3,3).
;
;     res : Output array (float) containing entropy,anisotropy and
;           alpha maps interlaced over the third dimension.  
;------------------------------------------------------------------
; This software has been released under the terms of the GNU Public
; license. See http://www.gnu.org/copyleft/gpl.html for details.
;------------------------------------------------------------------
function entalpani,arr
	siz    = size(arr)	
	anz_rg = siz[1]
	anz_az = siz[2]
   
   out = fltarr(anz_rg,anz_az,3)
	for i=0,anz_rg-1 do begin
		for j=0,anz_az-1 do begin
			cov = reform(arr[i,j,*,*],3,3)
			pol_eigen,cov,ew,ev
         res = pol_eaa(ev,ew)
         out[i,j,*] = res
		endfor
	endfor
	return,out
end