Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions on the exam.
  • Other questions.
• Quick reading review.
• Quiz.
• Lab.

Preliminaries

Admin

• Continue partners. (Those who weren't here on Wednesday can partner.)
• Extended/modified office hours continue next week.
• Welcome to any class visitors!

Upcoming Work

• Lab writeup: Exercise 5: http://bit.ly/151-2014F-w37
• Readings for Monday:
  • Design Elements
  • About the Project
• Exam 3 due Tuesday
  • Required prologue due tonight! http://bit.ly/151-2014F-exam3pro
  • Required epilogue due next Wednesday night. http://bit.ly/151-2014F-exam3epi

Cool Upcoming Events on Campus

• Peace studies talk Monday Nov. 10 at 4:15 p.m. in JRC 101 "With All the World’s Violence, Where is Peace?"

Extra Credit Opportunities

Academic

• CS Table TODAY: Open Data.
  12:10-12:50, Day PDR. (Readings available in the back of the room.)
• Jonathan Kozol talk tonight (7:30, probably Herrick)
• Scholars' Convocation, noon, Nov. 12: Dean Latham. In fall 2015, Convo returns to its proper time of 11 a.m. Thursday.

Peer Support

• Karan's radio show 11pm Thursday nights on KDIC
• Evan's radio show 5pm Friday nights on KDIC
• Donna's radio show Sunday midnight on KDIC
• The gaming club is hosting a Smash Brothers tournament on Saturday (Loose at 11am ...)
• Swimming on Saturday (1pm) against Luther.
• Drag Show Saturday

Exam Notes and Questions

Are there some questions and answers in yesterday's eboard?

Yes. I've also copied some of them into the exam.

What interesting questions have you seen in the prologue?

Amazingly, most of the people who have responded to the prologue included "start early" in their list of approaches.

Someone asked how many different tests I wrote for problem 2. My "first pass" set of tests explored eleven different issues, including two kinds of preconditions that might be checked.

Many of you seem overly enamored of append, particularly for problem 1. If you are only adding one element to the front of a list, you should probably use cons.

I'm trying to figure out what char-drypot is. Maybe auto-correct.

I appreciate that at least one of you noted that for both problems 5 and problem 6, you were likely to lose a lot of points if you failed to get the turtle back to the original position and orientation.

Can you try explaining repeat again?

(repeat N FUNCTION VAL) is a way to say "Do (FUNCTION VAL) N times."

(repeat N FUNCTION VAL) is conceptually equivalent to (for-each FUNCTION (make-list N VAL)), but without the extra work of making the list.

Should I use direct or helper recursion for problem 1?

It strikes me that direct recursion is better. I forgot to mention it on Wednesday, but if you're building a new list, and you want the elements mostly in the same order, direct recursion is often the way to go.

Can we see pictures for problem 8?

Done.

Should the procedures in problem 3 check their preconditions?

They need not do so in exams submitted for my section of the course.

_Should the string-rot13 procedure in problem 4 check its preconditions?

Yes.

Can I assume that capital A has collating sequence number 65?

No. The problem is fairly specific that you should not assume any particular collating sequence.

I hear rumors that some students have finished the exam already. Is that really the case?

"This is among the hardest exams I have ever taken. If you don't start it early, you will have no chance of finishing."

Other Questions

The Reading: Geometric Art

Two minutes with your partner

• What was the point?
  • You can draw complex repetitious things that still vary some aspects by using numeric recursion.
  • We might vary color or brush size or ...
• What was murky?
  • The closeness thing in the spacing.

Quiz

Lab

Use (context-set-brush! "2. Hardness 100" 2) and make sure that you have the brush tool selected.