so before we get into the actual code in

too much depth I want to talk a little

bit about how we control netlogo code

so we've talked a lot about the agents

and their structure and everything along

those lines but we haven't talked too

much about actually controlling the flow

so one thing that's fundamental to the

notion of an agent-based model is and is

really embedded within that logo but not

required is this notion of an initiation

phase and then in an iteration phase

write an initialization iteration phase

right

and in that logo the way that it's

suggested that you do that is by

creating a set up procedure and a go

procedure and now as you noticed in the

past right we have all these set up and

build buttons right and we've talked a

little bit about the set up and go code

right and those are kind of a great

example of how you might do this

initialization phase in this iteration

so we're gonna show you we're going to

divide down this model and split up this

model into a setup phase and it go phase

but there are a bunch of other commands

that also control and are related to

kind of be set up and go these initial

Asian initialization and iteration

phases so first of all it's the tick and

tick is a command that basically just

says this is the end of one of the

iteration phases it's tiny glance in

next one it just lets net logo know when

to change for instance the graphs right

and when to iterate the little tick

counter that we saw at the top of the

net logo world view right and then

there's if an if Allison if is

essentially conditional right it says if

this is true then do this right and if

else says if this is true then do this

else do this other thing right there's a

command called repeat that we may have

seen that we've seen a little bit of

before which says repeat something a

certain number of times and then there's

finally there's a command called wael

that says while something is true do the

following data loop so these are going

to come into play as we look through the

net logo code but given that kind of

context let me now pause for a second

and just

you what the setup and go code looked

like in the simply economy model and how

they contain some of these elements that

we've just discussed so here I pulled

open the Sybil economy model and the

smile is available under IBM textbook

chapter two in the net logo models

library so if you go up and you go up to

file a file Milo's library and you go

down to chaplain to IBM textbook and

then go down to chapter two it's simply

economy right so you can hit okay open

it up and it will show up in your net

logo application right and what we're

gonna do over the course of the next

couple of videos just go over this model

in detail and show you how it was

constructed right so just to give you an

example right as we mentioned the there

is a set up code and there is some go

code in this procedure and one of the go

codes uses the ask Turtles command that

we've talked about a little bit before

right to execute and it uses the width

right to do a collection of those

turtles right and have them carry out

some actions and here's that if command

that I talked about so if the wealth is

less than or equal to the max px core in

other words if they're about to move off

the screen set their export wealth and

won't get into the details about what

this exactly means and then there's

another one of these control variables

called tick right which control you see

tick usually at the end of every go loop

it tells the model that the time it

wants the next tick right if you'll

notice at the end of the setup procedure

there is a reset ticks command that also

controls when to reset the ticks and

that almost always happens at the end of

every reset danrage setup command right

and at the top of every set of man

there's almost always a clear off

command so the first thing I ever I do

almost inevitably when creating a new

model is type to set up clear all reset

ticks

and right and that kind of starts to

create the model that I need and then

all this type to go tick and and now I

have a basic framework that works for

almost every single got a little go

model right so let's take a second and

we're going to go back and we're going

to look at some of the setup procedure

for this particular model