Okay! the extension I wanna talk about

today is the network extension.

We already played around

with a little bit in unit 4.

But I mentioned a little bit

about how you could add

a calculation that would be much

harder to calculate in

that logo but putting

then into extensions.And

this model really exemplifies that.

That's why I wanna this talk about it

So, this is another viral

marking model of... you know...

it's ..in neuro we cal it diffusion

information. This is taking into the

the point - "I wanna find who is

the best person to see... what particular

messages if I want that message

to diffuse quickly thorugh .. the system.

and I have a budget, so, I can determine

how many different people

I can see.. I have a different

types of networks named in

preferential attachment like we saw

before. But now,I am also gonna have

a setting that isn't random or based upon

betweenness and betweenness is exactly

what I am talking about when

I am saying sometime it's better

to have a particular calculation

umm.. be written in another language

and then just have netlogo

use an extension to call it.

And that's because betweenness is a

really complex calculation.

What betweenness is calculating ..

is it's calculating how often a

node appears on the shortest path between

any of the other two nodes in

the entire network.right..

that involves comparing every node

in the network, finding each shortest

path to every other node in

the network and then figuring out. which

..how many ...and what nodes are on

those paths. As you might imagine

as we increase the size of the

network this calculation absolutely

explodes and in many cases

we don't waana put code like that

directly into a net logo model.right...

Instead, it's better to, spend some

time, develop a Java vesrion of

that.. another language version of that

particular code and then have net logo

simply call that version on the particula

err.. umm.. dataset that we are looking

at. That's exactly what the model

does.So, what it does is set up network