Overview

• Preliminaries
  • Admin.
  • About HW2
  • Questions on HW3
  • Clicker Questions.
• A new model of images making.
• Coding algorithms for drawing.
• Other useful techniques.
• Lab.

Admin

• I was in Pella, so brought you Dutch letters (enough for 1/2 each). Sorry to those of you who are gluten or almond intolerant. (I don't know about ingredients, but my peanut-allergic son and my treenut-allergic self are okay with them.)
• Study break, tonight at 8pm.
• Grading stuff
  • I finally finished grading HW1. Sorry for the delay.
  • Our grader has graded HW2 and I'll be returning it and commenting on it.
  • I'll be returning Friday's quizzes. Some of you may want to chat with me.
  • I'll distribute the exam tomorrow.
• Many things went wrong today - broken code, broken lab, etc. Sorry. It also means that I'm even more discombobulated than normal.
• Not quite lab writeup (due Wednesday):
  • Document using the six P's the rectangle procedure from the first lab on drawings.
  • Email to rebelsky@grinnell.edu, subject "CSC 151.02 Lab Writeup: Documentation"
• Reading for Tuesday: Design and Color
• EC Opportunities:
  • Convocation this Wednesday at noon in JRC 101 (see Sam's rant on the importance of convo in the outline for more details)
  • CS Extras Thursday @ 4:30: Kim Spasaro on Linguistics Programming
  • CS Table Friday (Pair programming)
  • Humans vs. Zombies
  • Other?
• I also encourage you to attend any of the other Title IX talks/events.

Comments on HW2

• I'll be returning them at the end of class.
• It would be nice to see you try more non-working or strange values
  • What happens if you use a negative number? A complex number?
  • What happens if you try a different number of parameters.
• Things like "least common multiple" and "greatest common divisor"
• Many of you left out examples / "tests"

Questions on HW3

• Who is my audience?
  • Your peers in this class, one week earlier

• When our code generates images, should we include the images?

  • Generally, no. We can regenerate them.
  • For the yellow rectangle

  (rectangle "yellow" ....) (drawing rectangle 43512315 0 0 20 20)

Clicker Questions

• NO CLICKER QUESTIONS TODAY

A new model of images making

• ON computers, we often draw with an application
• New model: Tell the application what to do "Select this brush" "Drag from here to here" "Fill the selected region" ...

Coding algorithms for drawing

• What we can do by hand, we can do "by code"
  • It's more precise. We can be more perfect than we can by hand.
  • It's easier to replicate (we can copy/paste instructions instead of images)
    • We can rerun the instructions
  • We can decompose how the image is created
  • We can change the code and generate a related image (without affecting the original).
    • Easy to fix errors!
  • We can do long, repetitious tasks more easily
  • In some deranged circles you get geek cred for writing programs to make images

Other useful techniques

Lab