CSC151.01 2014F, Class 22: Images as Functions from Position to Colors

Overview

Preliminaries

Maintain partners!
Happy (belated) birthday LG!
I've been asked to check if anyone is planning on taking TEC 154 in the spring.
On Wednesday, I spent about twenty minutes going over the material. On Friday, I spent no time. What's the right amount of time for you? (I will close my eyes while you answer.)
- 5 minutes, or less
- Around 10 minutes. The consensus result.
- Around 20 minutes.
- Whatever.
If you'd like to see a very different approach to today's material (not in Scheme, but some similar ideas), head over to the beta of my summer students' software at http://glimmer.grinnell.edu
Office hours
- Normal (MThF 1:45-3:15; walking 1:15-1:45)
- In the Grill 8:00-9:30 Wed and Fri (no signup)
- In my office 8:00-9:30 Tue and Thu

Grinnell Prize events this week (particularly events related to the prize winners whose project involves Web tools)

Football (Saturday at 1pm)
Men's Tennis (???)
Women's Tennis (???)
Swimming (???)
Karan's radio show 11pm Thursday nights on KDIC
Evan's radio show 5pm Friday nights on KDIC
Donna's radio show Sunday midnight on KDIC
The College's version of Anna Christie, Oct. 9-12 (SB plays Marthy) Thursday night, Saturday night, Sunday afternoon

What should I do when hsv->rgb complains about rational numbers?

You need an integer for the angle.

What about angles of 360 degrees?

It fails miserably. And for once, it's not my fault.

Spend two minutes discussing the reading and self checks with your partner.
Let me know what questions you have.
Reminder: You are supposed to do (or at least reflect on) the self-checks before class.

Yes, you can check colors using image-get-pixel if you are unsure as to whether you've achieved goals.

Here's the pattern I'd expect you to use for problem 3

(define whatever
  (lambda (width height)
    (image-compute!
     (lambda (col row)
      (FORMULA))
     width height)))