EECS 110: Lec 2: What is Programming? Aleksandar Kuzmanovic Northwestern University http://networks.cs.northwestern.edu/EECS110-s17/

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!

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).

Communication Professor: akuzma@northwestern.edu TAs: Annie Akbar, QuratUlAnnAkbar2015@u.northwestern.edu Melissa Perez, MelissaPerez2019@u.northwestern.edu Yousef Issa, yousef@u.northwestern.edu Kevin Wilde, KevinWilde2018@u.northwestern.edu Group e-mail: via Canvas

Homework Assignments Collaboration Honor Code ~ 4-5 problems/week ~ 100 points 20-25% 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

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.

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: http://networks.cs.northwestern.edu/EECS110-s17/cs5book.pdf (there is a direct link from the documentation page)  The book is recommended, but NOT required

Software and Web site Web page: Programs: Python and Idle http://networks.cs.northwestern.edu/EECS110-s17/ Programs: Python and Idle open source, free from www.python.org installation instructions on the Web site MAKE SURE TO DOWNLOAD python-3.5.1

Submission site https://canvas.northwestern.edu Problems/issues: QuratUlAnnAkbar2015@u.northwestern.edu

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?

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!

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

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)

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

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.

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

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.

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

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

Ideas for the maze? the maze

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 >>>

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

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

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

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

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

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.

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"

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

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

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

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

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

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, '!')

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, '!')

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 …

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…