• 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
• Exam 1
  • Electronic due Tuesday at 10:30: http://bit.ly/151-2015F-exam1
  • Printed version due Wednesday at start of class.
  • Epilogue due Wednesday at 10:30: http://bit.ly/151-2015F-exam1epi
• Today's Lab writeup (due before class Wednesday)
  • Email to grader-151-01@cs.grinnell.edu
  • 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