CSC151.01 2014F, Class 37: Geometric Art Through Numeric Recursion ================================================================== _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: * Readings for Monday: * [Design Elements](../readings/design-elements.html) * [About the Project](../assignments.project.html) * [Exam 3](../assignments/exam.03.html) due Tuesday * *Required* prologue due **tonight**! * *Required* epilogue due next Wednesday night. ### 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](../eboards/extra.09.html)?_ > 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.