CSC151.02 2016S, Class 14: Drawings as Values
=============================================

_Overview_

* Preliminaries.
    * Admin.
    * Upcoming Work.
    * Extra Credit.
    * Questions.
* Lab.

Preliminaries
-------------

### Admin

* New partners!  
* New lab.
* I think I've responded to every email question I've received.
* Sam's evening: Class. Talk. Dinner. Senior Showcase. Sleep.

### Reminders

* Office hours: MTWF 10-11, Tu 1-2.
    * Sign up at <http://rebelsky.youcanbook.me>.
    * Also feel free to stop by when my door is open.
    * Or to email me for an appointment.
* Tutor hours
    * Sunday, 3-5 p.m.
    * Sunday-Thursday, 7-10 p.m.
* Weekly review sessions:
    * Wednesday at 8pm in the CS Commons with Evan.
    * Thursday at 10am in this room with SamR!
    * Thursday at 8pm in the CS Commons with Kumar.

### Upcoming Work:

* Reading for Wednesday:
    * [Making and Manipulating Homogeneous Lists](../readings/homogeneous-lists-reading.html)
* [Exam 1](../assignments/exam.01.html) 
    * Exam due TONIGHT at 10:30 p.m.
    * [Epilogue](http://bit.ly/151-2016S-exam1epi) due Tuesday at 11:00 p.m.
    * Cover sheet due Wednesday at the start of class.
* Quiz Friday: Pictures!
* Lab Writeup: Exercises 4ab
    * Send email titled __CSC 151 Lab Writeup 14 (Your Names)__
    * Do not include the underscores.
    * Send to <CSC151-02-grader@grinnell.edu>
    * Due before class on Friday.

### Extra Credit

* Send your reports to <rebelsky@grinnell.edu> with subject 
  "CSC 151 Extra Credit".
* Send opportunities to me before class with subject
  "CSC 151 EXTRA CREDIT OPPORTUNITY!"

#### Academic

* Convocation: Hilary Mason '00 on Data Science and Social Good.
  (11 a.m., Thursday, JRC 101)
* CS Extras: Hilary Mason on Fast Forward Labs.
  (4:30 p.m., Thursday, Science 3821)
* Talk on diversity in education Irma McClaurin '73 at 6pm in ARH 302 
  with dinner.

#### Peer

* Swim Meet, Friday, Saturday, and Sunday, Osgood Pool.  (30 min.)
* Sign up to time!
* Lunar New Year Festival, 5:40 pm until 7:30 pm in Harris.
* Pun Club Tournament Friday the 26th in the evening.
* Contra Dance Friday the 26th in the evening.
* Improv Show the 27th in the evening in Loose Lounge.

#### Miscellaneous

* Important networking event in Des Moines.

#### Regular Peer

* Social Dance Workshop Tuesdays 7:00-8:00 in Bucksbaum Dance Studio
* Pun club Saturdays at 4pm in Younker (max 2)
* Electronic Potpourri on KDIC Fridays at Five (TONIGHT)
* Space Odyssey KDIC Fridays at Six

### No Extra Credit, But Still Good

### Exam Questions

_Do you really mean `(- 1 color)` on problem 6?_

> Yes.  Think about using 3/4 for `color`.

_Do you have recommendations for values to try for the first parameter
 in problem 6?_

> I'd try 0, 1/4, 1/3, 1/2, 2/3, and 1.

_I've written a computation that gives me 0 for one set of numbers and
 1 for another set of numbers.   I really want to get 1 for the first set
 of numbers and 0 for the second set.  Do you have any tips?_

> `(- 1 x)`

_Does that have anything to do with the `(- 1 color)` above?_

> I don't think so.

_What is a unique song?_

> Don't count the second (or third, or fourth, or forty-second) instance
  of a song.  

> Two versions of the song are considered different.  E.g., Venus in Furs
  on The Velvet Underground and Nico sounds very different than Venus in
  Furs on Live at End Cole Avenue.

_In what format should we write helper procedures?_

> Preferred

        ;;; Procedure:
        ;;;   helper
        ;;; Parameters:
        ;;;   x, a number
        ;;; Purpose:
        ;;;   Add 1 to x
        ;;; Produces:
        ;;;   whatever, a number
        (define helper
          (lambda (x)
            (+ 1 x)))

> Acceptable

        ; Add 1 to x
        (define helper
          (lambda (x)
            (+ 1 x)))

_Do we have to run formal tests?_

> No.  Just try it out. [Citation: "Just try it out." is a phrase used
  by ZG in class.]

_What do you want for citations to class readings and such?_

> Rebelsky, Samuel (2016). Academic Honesty. Grinnell College Department of Computer Science. Available at http://www.cs.grinnell.edu/~rebelsky/Courses/CSC151/2016S//handouts/academic-honesty.html (Last modified 14 January 2016; Visited 10 January 2016). 

> But I will accept

> Web page at  http://www.cs.grinnell.edu/~rebelsky/Courses/CSC151/2016S//handouts/academic-honesty.html 

_On problem 6, can our code crash and burn if the three are not all
 different._

> Yes.  You can crash.  You can return 3.  You can return 1.  You can
  return 42.  You can return a different number.  The three numbers
  being different is an important precondition.

_Can I use `irgb-add` with `compose`_?

> Yes, provided you also use it with section.

Lab
---

Writeup: 4a and 4b