Welcome to Introduction to Complexity.

This is a tutorial video for homework
number 1, the beginner's option.

Go ahead and open the NetLogo model
labelled 'multiple ants.nlogo',

which is available on the course materials
section of the website.

once it comes up, the interface
should look like this:

and you can go to also the 'info' tab
to read about the model,

as well as the code tab, to see how
the code is written and to change the code.

So first, let's just walk through the model,
see how it works.

Start by pressing 'setup'
and then press 'go', and wow,

we see that the model is running
very quickly,

so the first thing we should do is
slow it down.

Go up to the 'speed' slider at the top
of the screen, and we'll move it over

to the left, just a little bit.

Run the model again. Press 'setup' again,
and the first question in the homework

is to change the size of the ants.
So in NetLogo, all the agents are referred

to as 'turtles'. In this particular model,
the 'turtles' are ants.

So 'turtles' and 'ants' are synonomous.
Don't get confused by that.

So we'll go to the setup procedure, which
is the first procedure in the code.

And, find where it finds set size.

And, we are going to change that from 1 to 2.

It's as simple as that.

We can check the code to make sure

it is error free.

It is.

We'll go back to the interphase and click setup again.

And now you can see the ants are a little bigger.

So, I can press Go to Stop.

And the next question is to eliminate the labels.

We can go back to the interphase.

And we can see each ant has a little numeric label

which refers to how many patches it has eaten.

So we are going to eliminate this label.

We are going to go to the code

and scroll down.

To the go procedure

and find where it has set food eaten

and we will just comment this out.

To comment something out

simple type semi-colon (;) before the line

and that grays out the line

and it is no longer part of the code.

You can still see it

and you can always bring it back by deleting that

semi-colon

So we will go back to the interphase.

Setup, press Go.

and you can see the labels are now disappeared

So the next question is to change the color of the ants.

depending on how much food they have eaten.

So, go back to the code.

and just below that last line.

We will add another line

We will insert the cursor here.

And we will write a true-false statement.

Then, a command statement

So first let's say if food eaten is greater than 2.

That is either true or false.

then the command, which requires

it be in brackets.

Be to set the color blue.

Close bracket.

let's check that.

It looks ok.

We will go to the interphase.

And now we scan see some of the ants turn blue.

After they have eaten more than two patches.

So now we are asked again to change

the color of the ant when it has eaten

four green patches

this is basically the same code

if food eaten is greater than four

bracket, set color yellow, close bracket.

That's a bracket.

Check.

Back to the interphase.

Setup. Go.

and you can see now that there are some yellow

ants as well,

So we have red, yellow, and blue ants.

A variety of different fed ants.

And that includes the beginner section of homework one.