CSC151.01 2015F, Class 14: Boolean Values and Predicate Procedures ================================================================== * New partners! * Grab a card from the stack. * Identify the location of the new computer. * Drop the card in the jar. * When both of you are at the computer, introduce yourselves. * Welcome prospective students (if there are any) _Overview_ * Preliminaries. * Admin. * Upcoming Work. * Extra Credit. * Questions. * Lab. Preliminaries ------------- ### Admin * Review sessions: * Wednesday, 8pm (Zachary) * Thursday, 10am (Sam) * Thursday, 8pm (Caleb) * I graded all of the lab 12 and lab 13 writeups I had received by 8pm on Sunday night. The rest will be graded significantly later. * If you find that you are struggling, we do have individual tutors available. * Let me know if you have questions on the quiz (other than my stupid answer to problem 1) ### Upcoming Work * Reading for Tuesday [Drawings as Values](../readings/drawings-late-reading.html) * [Exam 1](../assignments/exam.01.html) * Electronic due Tuesday at 10:30: * Printed version due Wednesday at start of class. * Epilogue due Wednesday at 10:30: * Today's Lab writeup (due before class Wednesday) * Email to * Subject: _CSC 151 Lab Writeup Class 14 (Your Names)_ * Exercise: 1c, implement `greyish?` ### Extra Credit Opportunities * I remain a little behind in responding to these. Sorry! #### Academic * Any visit to the current show in the Faulconer gallery * John Gerrard talk, "Corn Bomb", tonight at 8pm. Bucksbaum 152, we think. * No CS Table this week - It's advising week! * Wednesday CS Extra this week, 4:15 in 3821: Ursula Woltz on Building Coding Communities * Thursday CS Extra this Week, 4:15 in 3821: SamR on The Architecture of Mediascript #### Peer Support * Pals of PALS, pals@grinnell.edu, normally Saturday at 7:45 am (breakfast included), Sunday at 4:45, and Mondays at 4:45. Requires sign up in advance. Fundraiser thing coming soon. * Pun Club, Saturdays, 4pm, Way over Younker. * Singers concert on Family weekend! Sept. 26, 2pm., Sebring-Lewis * Orchestra concert on Family weekend! Sept. 26, 2pm., Sebring-Lewis ### Exam Questions _I'm stuck on Problem 2. Any hints?_ > Tell me what problem from HW3 you think it's closest to. > Although it was not intentional that things worked out this way, use ideas from today's extras. (I'd prefer that you not use this approach, but it's legal.) _I'm stuck on Problem 5. Any hints?_ > Try an `n` of `736145` and various values of `i`. > (fun 418265 1) 6 > (fun 418265 2) 2 > (fun 418265 3) 8 _On question 4, do we have to take into account negative times?_ > I was trying to say the following in more polite terms: `add-times` is not defined with negative times, so it is wickedly stupid to try to write tests with negative times. _On question 2, what do we do when two numbers are largest?_ > Whatever you'd like. You can always give the same answer. You can give different answers. You can make the computer explode in a shower of sparks. You can give back 1, 2, or 3. You can give back 0. _On question 3, do we have to use the procedures you gave us?_ > CC and I spent literally days (or fractions thereof) writing those procedures. Of course you have to use them. _On question 5, how do I figure out the numerator and denominator?_ > Follow the parens! _How do you grade the exam?_ > I grade each problem on a ten point scale. > I add the seven scores together. > I multiply by 10/7. > I add the designated extra points (e.g., for recording times). > If the grade is lower than 70 and the "there's more to life" requirements are met, I set the grade to 70. > I subtract the designated penalty points (e.g., for failing to do the prologue or epilogue) Lab --- Writeup: 1c, `greyish?` We are now hitting points in which Scheme thinks differently than humans. > (>= 8 1 5) #f > (>= 8 (and 10 200 2)) #t > (>= 8 (and 10 2 200)) #f