The next step is for you to try out Net Logo and to do an exercise and a quiz.
The exercises and the quizzes in this course are optional and don't count
for your grade, but I highly recommend doing them to helping your learning
the course material and also to test your understanding of what we've done so far.
This exercise is going to use a slightly modified version of the ants model
from the models library, the modified version is called "AntsNew.nlogo".
You can download this modified version by clicking on the "AntsNew.nlogo" link
below the video window, or by going to the course materials page.
So let me show you how to do that: here I am on the page with the video window,
under this video, you should see "AntsNew.nlogo".
I click on it, it asks me if I want to save it, so I do,
it's a binary file, [click] "save". And here we...it shows up on my desktop
because I saved it to my desktop, and I double-click on it to open it up.
And it should open up with ants"AntsNew", the new ants model, loaded into NetLogo.
Let's go back to look at the exercise.
It asks us to set the population to 200 and the diffusion rate to 20,
and then test three different evaporation rates to see which one makes the ants
eat all the food the fastest.
Well, each one of these is going to have a variety of times it takes for the ants
to eat all of the food, because there is randomness in the program.
What you are going to do is run the model 5 times for each of these values,
and for each run, record the number of ticks it takes
until all the food is eaten.
Now, remember to click "Set up" before each run.
At the end, you average those five numbers
for each of these settings of evaporation rate,
and then see which average time is the fastest.
So let's try that.
The population is 200, we set the diffusion rate to 20 by sliding it,
and let's start with evaporation rate with zero, so I do "Set up" and then "Go"
And again I can increase the speed by sliding this speed bar.
And now I see that it took on this run, 613 ticks for the ants
to eat all of the food.
I do it again,
"Go".
And that time it took 758 ticks for the ants to eat all the food.
So you would do that 5 times, average those 5 numbers,
and then you would set the evaporation rate to 5
for the next set of experiments and then to 20.
And remember to do "Set up" each time you start a run.
And after you do this exercise, there will be a quiz to ask you to think about
why you see the behaviour that you see.