1. EECS 110: Lec 2: What is Programming?
Aleksandar Kuzmanovic
Northwestern University

2. elif perc >= .80: grade = ‘B'
Grading
Grades
if perc >= .90: grade = 'A'
elif perc >= .80: grade = ‘B'
elif perc >= .70: grade = 'C'
Based on points percentage
~ 75% Assignments
~ 25% Exams
Extra ~ 5% Participation
Midterm Wed April 26
Exams
Final Wed May 31
To pass EECS 110, you must have a passing grade on both the exams and HW. I will also give quizzes in the class, but they will not be graded.
Note!

3. Getting help!
Labs
You should attend the labs because they will have you solve about 50% of your homework
Recitations
There will be a recitation class each Friday (10-10:50 am): help with the rest 50% of the homework
Office Hours
TA1: Friday 1-3 pm (Wilkinson).
TA2: Sunday 3-5 pm (Wilkinson)
Professor: Tuesday: 9-11:30 (Wilkinson).

4. Communication Professor: akuzma@northwestern.edu TAs:
Annie Akbar,
Melissa Perez,
Yousef Issa,
Kevin Wilde,
Group
via Canvas

5. Homework Assignments Collaboration Honor Code
~ 4-5 problems/week ~ 100 points % extra credit available
Due Sunday evening - by 11:59 pm. You can submit 3 homeworks 1 day later
"Late Days"
Some problems are specified “individual-only.”
Others offer the option of working in a pair.
Collaboration
You must share the work equally - typing and coaching
Each of you should make ONE submission (2 per team)
Be sure to indicate who your partner was at the submission site!
Honor Code

6. Honor Code
You may not share written, electronic or verbal solutions with other students (present or past):
You are encouraged to discuss problems with other students, TAs, or instructors.
Copying of files except those provided by the course material.
You will have the option of working in pairs for MANY of each week’s problems: the same guidelines apply for each pair.

7. Book
CS for Scientists and Engineers, by C. Alvarado, Z. Dodds, G. Kuenning, and R. Libeskind-Hadas (Note: this is a preliminary draft!)
 Available at:
(there is a direct link from the documentation page)
 The book is recommended, but NOT required

8. Software and Web site Web page: Programs: Python and Idle
Programs: Python and Idle
open source, free from
installation instructions on the Web site
MAKE SURE TO DOWNLOAD
python-3.5.1

9. Submission site https://canvas.northwestern.edu Problems/issues:

10. Goal: whole-environment coverage with only local sensing…
Homework problems 3 and 4
walls
Picobot
Picobot
area not covered (yet!)
area already covered
Goal: whole-environment coverage with only local sensing…
inspiration?

11. Goal: whole-environment coverage with only local sensing…
Picobot
walls
Picobot
area not covered (yet!)
area already covered
Goal: whole-environment coverage with only local sensing…
iRobot's Roomba vacuum
inspiration!

12. NxWx Surroundings N E W S
Picobot can only sense things directly to the N, E, W, and S N W E S
For example, here its surroundings are
NxWx
Surroundings are always in NEWS order.
N E W S

13. How many distinct surroundings are there?24
== 16 possible …
xxxx
Nxxx
xExx
xxWx
xxxS
NExx
NxWx
NxxS
xEWx
xExS
xxWS
NEWx
NExS
NxWS
xEWS
NEWS
(won’t happen)

14. State
I am in state 0.
My surroundings
are xxWS.
Picobot's memory is a single number, called its state.
State is the internal context of computation.
Picobot always starts in state 0.
State and surroundings represent everything the robot knows about the world

15. Rules Aha! I should move N. I should enter state 0.
I am in state 0.
My surroundings
are xxWS.
Aha!
I should move N.
I should enter state 0.
Picobot moves according to a set of rules:
state
surroundings
direction
new state
xxWS N
If I'm in state 0 seeing xxWS,
Then I move North, and change to state 0.

16. here, EWS may be wall or empty space
Wildcards
I am in state 0.
My surroundings
are xxWS.
Aha! This matches x***
Asterisks * are wild cards They match walls or empty space:
state
surroundings
direction
new state
x*** N
here, EWS may be wall or empty space

17. x*** -> N*** -> ***x -> ***S ->
What will this set of rules do to Picobot?
state
surroundings
direction
new state
x***
-> N
N***
-> X 1 1
***x
-> S 1 1
***S
-> X
Picobot checks its rules from the top each time.
When it finds a matching rule, that rule runs.
Only one rule is allowed per state and surroundings.

18. To do hw0, Problem #3 hw0, Problem #4 (Extra)
Write rules that will always cover these two rooms.
(separate sets of rules are encouraged…)
hw0, Problem #3
hw0, Problem #4 (Extra)
but your rules should work regardless of Picobot's starting location

19. Alter these "up & down" rules so that Picobot will traverse the empty room…

20. Ideas for the maze?
the maze

21. Python and Idle Editor window: code Shell window: running code
Here, you can save and change programs. Hitting F5 runs your program over in the shell
Here, you can try things out at the command prompt >>>

22. If statements (1) hw0pr1.py Homework 0, problem 1
name = input('Hi... what is your name? ')
if name == ’Ning': # is it Ning?
print('x1’)
else: # in all other cases...
print('x2’)
print('x3’)
hw0pr1.py
Homework 0, problem 1

23. If statements (2) name = input('Hi... what is your name? ')
if name == ’Ning‘:
print('x1’)
else:
print('x2’)
print('x3’)

24. What is computer science (CS)?
CS != programming
What is computer science (CS)?
Take EECS 101

25. What is computer science (CS)?
CS != programming
What is computer science (CS)?
Take EECS 101
"not equal to"

26. a vehicle, not a destination
CS != programming
programming : CS ::
machining : engineering
grammar : literature
Programming
equations : mathematics CS
a vehicle, not a destination

27. CS == computing science
Study of complexity (or complex things?)
How can it be done?
How well can it be done?
Can it be done at all?
Suppose we have a large group of students that we need
to pair up to work on projects. We know which students
are compatible with each other and we want to put them
in compatible groups of two. We could search all possible
pairings but even for 40 students we would have more than
three hundred billion trillion possible pairings.

28. CS == computing science
Study of complexity (or complex things?)
How can it be done?
How well can it be done?
Can it be done at all?
"equal to"

29. Information What information does Google work with?
What technical problems does Google face?

30. Information What information does Facebook work with?
What technical problems does Facebook face?

31. Information What information does the iPhone work with?
What technical problems does the iPhone face?

32. Computer Science and Information
Information is life’s fundamental building block
CS is a set of fundamental techniques for understanding and leveraging this information

33. Programming as learning a foreign language
What is programming?
Programming as learning a foreign language
1) Expect it to be different!
2) Don’t feel you need to memorize it
3) Immersion == Experimentation

34. The foreign language of Python…
syntax?
semantics?
intent?
How it looks
What it does
What it should do
name = input('Hi... what is your name? ')
print # prints a blank line
if name == ’Ning': # is it Ning?
print( name, '??’)
print(‘You must be a TA!')
elif name == ‘Aleksandar’: # is it Aleksandar?
print( ‘You must be an instructor!')
else: # in all other cases...
print( 'Welcome to Python,', name, '!')

35. The foreign language of Python…
syntax?
semantics?
intent?
How it looks
What it does
What it should do
name = input('Hi... what is your name? ')
print # prints a blank line
if name == ’Ning': # is it Ning?
print( name, '??’)
print(‘You must be a TA!')
elif name == ‘Aleksandar’: # is it Aleksandar?
print( ‘You must be an instructor!')
else: # in all other cases...
print( 'Welcome to Python,', name, '!')

36. The foreign language of Python
syntax?
semantics?
intent?
How it looks
What it does
What it should do
how punctuation is used
the language keywords that are used
use of whitespace
peculiarities of formatting
how behavior is affected …

37. HW 0, Problem 2 syntax? semantics? intent?
How it looks
What it does
What it should do
Save hw0pr1.py under a new name, hw0pr2.py
Change hw0pr2.py to play rock-paper-scissors.
It does not have to play fair!
Feel free to add to the dialog, if you wish…
Submit your hw0pr2.py in the usual way.
Stepping back from Python for a moment…