Added function spatial_diversity which calculate the geographical distribution of ties
Added function spatial_diversity which calculate the geographical distribution of ties

yvesalexandre/bandicoot,econandrew/bandicoot,ulfaslak/bandicoot,yvesalexandre/bandicoot,ulfaslak/bandicoot,econandrew/bandicoot,econandrew/bandicoot,ulfaslak/bandicoot,yvesalexandre/bandicoot