ABM Basics 3 & 2 (2)

Question 1

Which loop structure in Netlogo should you use if you want a set of commands to run a specific number of times?

Answer 1

Repeat loop structure

Question 2

Which loop structure should you use in Netlogo to run commands for each element in a list or agent-set?

Answer 2

Foreach

Question 3

How can we use the while command to create a list of 5 random numbers between 0 and 100?

Answer 3

let the_list []

while [ length the_list < 5 ]
[
set the_list lput (random 101)
the_list
]

Question 4

What is the main purpose of a .nls file in Netlogo?

Answer 4

To make the main file easier to read. This organises your code and it’s better for testing/structure

Question 5

How do you import a .nls file into your main Netlogo code?

Answer 5

__includes [“filename.nls”]

Question 6

Where should the .nls file be located in relation to the main .nlogo file?

Answer 6

Must be in the same directory

Question 7

What is the primary delimiter used to separate data in a .csv file?

Answer 7

Comma (,)

Question 8

Which extension must be added at the top your code to use .csv functionalities in NetLogo?

Answer 8

‘extensions [csv]’

Question 9

With the CSV extension in Netlogo, which command is used to convert a row of data from a .csv file into a list?

Answer 9

csv: from-row

Question 10

How would you load data from a .csv file named boroughs.csv into a list called borough_data using the Netlogo ‘csv’ extension?

Answer 10

let borough_data csv: from-file “boroughs.csv”

Question 11

What is the purpose of setting the coordinates of the bottom-left corner of the supermarket to (0,0)?

Answer 11

To establish the origin of the coordinate system

Question 12

How is the colour of each patch determined in the supermarket layout?

Answer 12

Assigned automatically based on keywords in a CSV file

Question 13

Where should the CRAVED vectors be stored for each patch?

Answer 13

In a patch attribute called CRAVED

Question 14

Explain the purpose of the set_colour_patches procedure in terrain .nls

Answer 14

It assigns global variables for the colours of each type of patch available.

By using global vars, we can easily adjust the colours in one central location rather than changing the colour in each individual patch’s code

Question 15

What is the purpose of the add_products procedure in relation to CRAVED attributes?

Answer 15

Created to assign CRAVED values to each shelves patch, showing how likely items on those shelves are to be stolen.

This procedure reads CRAVED values from the .csv file and assigns them as a list of numbers to the CRAVED attribute of each patch

Question 16

Write the procedure that checks if a given patch is an intersection patch and, if so, changes its colour to pink.

Answer 16

to check_intersection
ask patches
[
if category = “intersection”
[
set pcolor colour_intersection
]
]
end

Question 17

What are the elements in an ABM?

Answer 17

Elements in an ABM:
Agents - turtles
Environment - patches/terrain
Actions and interactions

Question 18

What does the environment do?

Answer 18

Environment defines the grid which the agents can go to

Question 19

What is a primitive command?

Answer 19

Primitive commands describe an action for the programme to do (i.e., ask turtles [set color yellow])

Question 20

What is a primitive reporter?

Answer 20

Primitive reporters carry out operations and report the result (i.e., report patches with [pcolor = green])

Question 21

What is a variable?

Answer 21

Variables are used to label information that we want the prpgram to store.

Question 22

What is a primitive variable?

Answer 22

Primitive variables in NetLogo are variables that are already named and stored in a NetLogo model (i.e., colour of a turtle - color; colour of a patch - pcolor)

Question 23

Write the code when you want the color of the patches to be set in the value of green

Answer 23

ask patches [set pcolor green]

Question 24

How could we assign random colours to the sheep?

We could use set to assign or change the value of a variable. Colors in NetLogo range from 0 to 140

Answer 24

ask sheep [ set color random 141 ]

Why 141? The random command is 141 because you want to include all colours in the shade provided

Question 25

how can we tell turtles to move forward 1 patch if their colour is red using the if command?

Answer 25

Ask turtles [If color = red [ forward 1]]

Question 26

how can we tell turtles to move forward 2 patches if their colour is red and forward 1 patch otherwise?

Answer 26

Ask turtles [ ifelse color = red [forward 2] [forward 1]]

Why? Follows this: Ifelse boolean 1 [commands1][elsecommands]

Question 27

Turtles have now an energy attribute, a numeric value ranging from 0 to 100. How can we tell turtles to:

1. Move forward 1 patch if their energy is less than or equal to 25,
2. Move forward 2 patches if their energy is less than or equal to 50 but more than 25,
3. Move forward 3 patches if their energy is less than or equal to 75 but more than 50,
4. Move forward 4 patches if their energy is less than or equal to 100 but more than 75

Answer 27

ask turtles
[(
ifelse energy <= 25 [ forward 1 ]
( energy <= 50 AND energy > 25 ) [forward 2]
( energy <= 75 AND energy > 50) [forward 3]
[forward 4]
)]

Question 28

What are lists

Answer 28

Lists are a collection of variables and elements are separated by spaces

Question 29

How can you add items into a list?

Answer 29

Add value to the end of the list you do ‘lput’
Add item to the beginning you do ‘fput’

Question 30

We want to add a random number between 0 and 100 to the end of the_list (a list that has been previously created) How do we do it?

Answer 30

set the_list lput (random 101) the_list

Question 31

Remember that within a list, each element is an item and is numbered according to its position (starting at 0).

1. Which is item 3
2. What is the position of 4
3. What is the length of the list

list = [ 2 4 6 8 10 ]

Answer 31

1. 8
2. 1
3. 5

Question 32

Reports a list containing the given items, the items can be any type, produced by any kind of reporter

If the list is made by reporters (i.e., random 100) use the “list” command

Answer 32

Set name_of_list list (random 100) (random 100)

Question 33

What is the greater than less than sign

Answer 33

> = <
greater than; equal to; less than