function?[sector_num]?=?whichsector（index）
%?Modiofied?by?Luigi?Rosa
%?index?is?the?index?of?current?pixel?of?cropped?image?（?cropped?image?is
%?175?x?175?）;?sector_num?is?the?output?and?represents?what?is?the
%?corresponding?sector.
global?immagine?n_bands?h_bands?n_arcs?h_radius?h_lato?n_sectors?matrice

length?=?h_lato;
x?=?rem（?index??length?）;
y?=?floor（index?/?length）;

x?=?x?-?floor（length?/?2）;
y?=?y?-?floor（length?/?2）;

rad?=?（x*x）?+?（y*y）;
if?rad?????sector_num?=?（n_sectors-1）+1;
????sector_nu