Overview

• Preliminaries
  • Admin.
  • About Exam 1.
  • About Six+ P's
• Questions on Raster Graphics and RGB Colors.
• Lab
• Things in the outline.
  • Representing images, revisited.
  • Pixels and colors: The basics.
  • RGB colors.
  • Those weird numbers.

Admin

• We seem to have a misunderstanding about workload. If you're spending more than five hours on a homework assignment, something has gone wrong and we should talk.
  
  • Preferably, you would realize that you were going to spend that much time before, say, 8pm on Tuesday night.
  • If you hit more than five hours, it's making sense, and you really want to do the last bit, that's fine.
  • But if you're stuck, you should come to see me.
• Lab writeup: Extra 1 from today's lab, due Friday before class.
• Reading for Friday: Transforming RGB colors.
• It sounds like there may be room for one more person in Dr. Davis's 11:00 a.m. section of 151. So, if you'd like to switch sections, let her know asap.
• Yes, if you take CSC 161 you get to play with the red robots.
• I plan to email you your current grade info by Friday.
• SACNAS Ice Cream Social Thursday, September 19th at 8:00PM in the Biology Commons
• EC Opportunities:
  • CS Extras Thursday @ 4:30: Kim Spasaro on Linguistics Programming See http://www.cs.grinnell.edu for more info
  • CS Table Friday (Pair programming) See http://www.cs.grinnell.edu for readings
  • Other?
• I also encourage you to attend any of the other Title IX talks/events.
• We're going to try an experiment today. Instead of giving my start-of-class lecture and clicker questions, I'm going to let you ask about five questions on the readings.

Exam 1

• Exam 1 is ready. You can find it under the current assignment, the schedule, and the list of assignments.
• We'll quickly visit
  • Policies
  • Questions
• What if you have questions?
  • There will be time at the start of class for questions on Friday, Monday, and Tuesday.
  • I'll also add some Q&A to the exam itself. Please check it regularly.
  • I'll be available on Friday, Monday, and Tuesday.
  • I'll try to check email over the weekend. (However, I'm traveling this weekend.)

Six Ps

For future reference, I like a very careful presentation of the Six+ P's

• Line 1:
  • Three semicolons
  • A space
  • The keyword "Procedure"
  • A colon
• Line 2:
  • Three semicolons
  • Three spaces
  • The name of the procedure
• Line 3:
  • Three semicolons
  • One space
  • The keyword "Parameters"
  • A colon
• Next few lines
  • Three semicolons
  • Three spaces
  • The name of a parameter
  • A comma
  • The type of the parameter
• Next line
  • Three semicolons
  • One space
  • The keyword "Purpose"
  • A colon
• Next few lines
  • Each begins with three semicolons and three spaces.

For example

;;; Procedure:
;;;   whatever
;;; Parameters:
;;;   what, a string
;;;   ever, an integer
;;; Purpose:
;;;   etc.

• Why be so precise?
  • It's easier to read (or so experience suggests)
  • It's easier to write programs to process it (and yes, I've written such programs)

Questions on Raster Graphics and RGB Colors

No questions

Lab