Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions.
• Key Ideas
• Lab

Preliminaries

Admin

• Continue lab partners.
• Prof. Weinman is running class today.
  
  • Extra credit for sending me notes to post on the eboard.
• Mentor sessions tonight at 8:00 p.m. and tomorrow night at 8:00 p.m.
• Office hours: Thu/Fri 1:45-3:15; Also walking hours Thu/Fri 1:15-1:45.
• Don't forget the review session Thursday at 10 a.m.!

Quiz Topics

• Integer-encoded RGB colors and the basic operations on those colors.
• Standard color transformations.
• Image and pixel operations, including image-variant and image-transform!.
• compose and o.
• (Possibly): lambda expressions, as used with the image transformations.
• (Not): map and the other subjects we are doing today.

Upcoming Work

• Lab writeup: Exercise 5 http://bit.ly/151-2014F-w16 Due Friday.
• Printed copies of lab due at the start of class.
• Homework 4 due next Tuesday.
  • Groups distributed via email.
• Quiz Friday!
• Reading for Friday:
  • Boolean Values and Predicate Procedures

Extra Credit Opportunities

Academic

• Convocation TODAY: Tara Zahra on Emigration from Eastern Europe
  • Please tweet interesting points with tag #GCConvo
• CS Extras Thursday at 4:30: Mathematical Image Synthesis Toolkit (MIST)
• CS Table Friday at noon: ???
• Campus Town Hall September 30

Peer Support

• Noteworthy, Sat., Sept. 27, 3:30 p.m. Herrick
• Science poster session, Sat., Sept. 27, morningish, science elbow
• Football Games (Saturday, Sept. 27, at 1pm)
• Men's Tennis (???)
• Women's Tennis (???)
• Swimming (???)
• Anna Christie, Oct. 9-12 (SB plays Marthy)
• Evan's radio show 5pm Friday nights on KDIC
• Donna's radio show Sunday midnight on KDIC

Miscellaneous

• Participate in #GrinWell. http://www.grinnell.edu/forms/sign-grinwell-presidents-wellness-challenge
• Friends of Drake Library needs help setting up for their annual booksale on Thursday, October 2 (conveniently, the same night as Grinnell High School's homecoming parade). You can help a good cause and probably get a few free books, too.
  • Update: They can also use help on Wednesday, October 1.

Questions

Key Ideas

• A list is a collection of values, in an order.
• You can build lists using list (specific values), iota (values from 0 to n-1), and make-list (multiple copies of the same value)
• You can build a new list by using map to apply a function to each element of a list.
  
  • map is much like image-variant, except for lists rather than images. (That is, both apply a function to each element in a collection and return a newly computed collection. In one case, it's an image. In the other, it's a list.)
  • map can also take multiple lists, and applies the function to corresponding elements of each list.

Lab

• Have fun!
• Ask questions!