EBoard 27: Vectors, continued again

Warning This class is being recorded (and transcribed), provided Sam remembered to hit the “Record” button.

Approximate overview

• Administrivia
• Activity
• Questions
• Lab

Administrivia

• Happy November!
• Happy NaNoWriMo, if any of you celebrate!
• Our graders say that MP4 is finished. If you don’t seem to have a grade, please let me know.
• Please grab a sheet of paper from the back of the room.

Upcoming Token activities

Academic

• Mediating Polarizing Debates, TODAY at 4pm in the HSSC Kernel (aka “Multipurpose Room”, A1231).
• Scholars Convocation, Thursday at 11am in JRC 101. Jarvis Givens on “Black Reconstructions: Archival Assembly and the History of African American Education”
• CS Extras, Thursday at 4pm: Side-Channel Attacks

Cultural

• Shift, the Documentary about RAGBRAI, 4:15 pm, Thursday, in the HSSC Auditorium.
• An evening of Ukranian Poetry and Music, Thursday, November 2, at 7:30 pm.

Peer

• Awesome physics talk TODAY at noon on making pretty pictures of galaxies. Noyce 1023.
• Women’s Volleyball vs. Cornell, TODAY at 7pm. Wear pink! Show up early for a pink t-shirt.
• Swimming vs. Iowa Central CC, Friday, November 3, at 6pm.
• Football vs. UofC, Saturday, November 4, at noon

Wellness

Misc

Other good things (no tokens)

Upcoming work

• Today: SoLA 2 (due Thursday at 10:30 pm)
• Thursday night: Reading on randomness
• Friday: Pre-class quizzes (7:30am; finish by 8:30am)
  • Diagramming structures
  • Vectors and vector recursion
  • Tracing (if you ask in advance)
• Sunday: Various MP redos (posted to Gradescope)

Comments on Pre-Assessments

I looked at the first dozen or so pre-assessments. I’d like to see deeper brain dumps. I also think it would help you. (Evidence suggests that brain dumps help in every class.)

• What procedures are relevant?
• What are common program structures (e.g., for list recursion or numeric recursion)
• What procedures have you written or read? What do they look like?

Let’s practice: Brain dump on vectors. Spend five minutes writing down what you can remember (focusing on things like the above).

Questions

Registration

What are the odds that CSC-161 will be available after priority registration.

I’ll tell you Friday at 11:59 pm, when I see the waiting list numbers.

29 + 24 + 24 = 77 students who might want to take 161. If our class is representative, there are 80-90% of students who want to take 161. .8 * 77 ~= 62.

There are 48 slots available. Damn. Maybe the other sections don’t like CS as much as you do.

I’m guessing most people will put it in round 1, and it will be full.

Will I get into CSC-161?

I certainly hope so. That’s the department’s goal. But we can’t work magic.

Is it bad to priority register for two classes?

No. The two should not affect each other.

Can I hack the computer system to increase my priority?

Please don’t.

Is prioritizing two sections of the same class a good idea?

Yes, if you can. They count as one class (or are supposed to) and it increases your odds.

Should I learn game theory to optimize my chances and then look at what things look like Friday at 11:50 p.m.?

Sure.

Vectors

Administrative

If we don’t get into CSC-161 and we want to be CS majors, what should we do?

Remember that you can start a CS major as late as your third semester; it will be fine if you take CSC-161 in the fall. (And third-semester students will be prioritized for CSC-161 in the fall.)

Take one of the hundreds of other awesome courses Grinnell offers.

SoLA 2

How will we know if we should take the quizzes on vectors or diagramming structures on Friday?

I will do my best to grade any of those that come in by 7pm on Thursday.

Other

Lab

Finally, we get to do a lab on vectors.

IF YOU FINISH EARLY, PLEASE WRITE

;;; (ivec-closest-to-zero vec) -> integer?
;;;   vec : vector-of integer? (nonempty)
;;; Find an element of vec whose absolute value is less than or
;;; equal to all the other elements of vec.

(test-equal? "singleton, positive"
             (ivec-closest-to-zero (vector 10))
             10)
(test-equal? "singleton, negative"
             (ivec-closest-to-zero (vector -5))
             10)
(test-equal? "a bunch of values, positive closest to zero at end"
             (ivec-closest-to-zero (vector 9 -3 22 -11 -2 5 1))
             1)
(test-equal? "a bunch of values, negative closest to zero at front"
             (ivec-closest-to-zero (vector -2 44 -7 -8 -4 11 3 15))
             -2)
(test-equal? "a bunch of values, positive closest to zero in middle"
             (ivec-closest-to-zero (vector -2 44 -7 -8 1 -4 11 3 15))
             1)