***** To join INSNA, visit http://www.insna.org ***** Hi I made a few experiments myself. I created in Pajek 5 Random Erdos-Renyi Undirected General Graphs with n=100, and avg. degree=3, and calclulated their avg. geodesic distance with Pajek>Net>Paths between 2 vertices->Distribution of Distances->from all vertices. Results range from 3.69 to 4.62, i.e. they hover around the predicted 4.191 with quite some variability. Then I did the same for the network parameters I am interested in, i.e. n=418 avg. degree=87. For all 5 networks I get an avg. geodesic of 1.79etc, which is consistently different from the predicted 1.35. Could it be that the ln(n)/ln(avg.degree) formula applies only to sparse networks? Thanks, Gianluca > Did you make a Random Erdos-Renyi Undirected General Graph? > > The approximation you gave may be applied to only random ER graph. (there > are more general approxiations that can be applied more general graph). > > And you get the average distance of graph using Net->Paths between 2 > vertices->Distribution of Distances->from all vertices menu. > > I did two experiments. > > 1. 100 nodes, average degree 3. > approximation : ln(100)/ln(3)=4.191, real : 4.41981 > 2. 1000 nodes, average degree 5. > approximation : ln(1000)/ln(5)=4.292, real : 4.48113 > > Is it almost same? > > Best. > > ----- Original Message ----- > From: "[log in to unmask]" <[log in to unmask]> > To: <[log in to unmask]> > Sent: Tuesday, December 07, 2004 9:07 PM > > > > ***** To join INSNA, visit http://www.insna.org ***** > > > > Hi everybody, > > > > The avg. geodesic distance in a (connected) random network is approximated > by ln(n)/ln(k), where n=number_of_nodes , and k=avg._ties_per_node. However, > if I create a random network with parameters n and k in Pajek and calcluate > its avg. geodesic distance, I get sizeably different results (regardless of > how large I set n). Any idea what I could be doing wrong? > > > > > > Thanks, > > > > Gianluca > > > > > > PS: To calculate the avg. geodesic distance I've been using > > Ucinet/network/cohesion/distance -->adjacency > > > > > > > > > > > > ____________________________________________________________ > > Libero ADSL: 3 mesi gratis e navighi a 1.2 Mega, senza costi di > attivazione. > > Abbonati subito su http://www.libero.it > > > > _____________________________________________________________________ > > SOCNET is a service of INSNA, the professional association for social > > network researchers (http://www.insna.org). To unsubscribe, send > > an email message to [log in to unmask] containing the line > > UNSUBSCRIBE SOCNET in the body of the message. > > > > Gianluca Carnabuci PhD candidate University of Twente P.O. Box 217 Enschede The Netherlands Ph: 0031 53 4892352 ____________________________________________________________ Libero ADSL: 3 mesi gratis e navighi a 1.2 Mega, senza costi di attivazione. Abbonati subito su http://www.libero.it _____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.