• Continue partners!

Overview

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

Preliminaries

Admin

• Please remind me when I have not posted the eboard.
• We'll spend some time today on exam questions.

Reminders

• Office hours this week
  • See http://rebelsky.youcanbook.me.
  • I'm working on adding more.
  • I'll soon respond to requests for special times.
  • I should be gone next Monday and Tuesday :-(
• Tutor hours
  • Sunday, 3-5 p.m.
  • Sunday-Thursday, 7-10 p.m.
• Weekly review sessions:
  • Wednesday at 8pm in the CS Commons with
  • Thursday review session this week with Sam.
  • Thursday at 8pm in the CS Commons with

Upcoming Work:

• Reading for Wednesday
  • Verifying Preconditions
• Exam 2 due NEXT TUESDAY.
• Quiz Friday: Recursion basics.
• Lab Writeup: Exercise _
  • Send email titled CSC 151 Lab Writeup 26 (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". (Do not include the quotation marks.)
• Send opportunities to me before class with subject "CSC 151 EXTRA CREDIT OPPORTUNITY!"

Academic / Artistic

• TONIGHT at 7:30 p.m. in Herick: Six Appeal
• Friday at 4:00 pm. in Burling: Decolonizing Digital Humanities

Peer

• 4:00 p.m. TODAY, ISO Travel Fair.
• The Tempest. This weekend. 7:30 Friday and Saturday, 2:00 Sunday. Tickets in Bucksbaum box office.
• Salseros Friday at 8:30 pm in Garnder. Food! The JS non-brothers, sighing deeply.
• 8:00-10:00 show with various cool jazz-funk folk. No free food.
• Sunday, 6:00-8:00 AAA Potluck in JRC 209. Free ingredients!

Regular Peer

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

Misc

Far in the Future

• Lords of the Flies, April.

No Extra Credit, But Still Good

• Indoor track nationals.

Questions

How do we do a blue blend? (We want to do something similar on the exam, so I thought I should ask.)

Suppose we have an image of a specified width, and we want to know how far along, a point (x,y) is. What do we do? Divide by the width, or the width-1.

If you are p of the way along, and the blue component ranges from 0 to b, use p*b to compute the blue component.

(define horiz-blue-blend
  (lambda (width height initial final)
    (image-compute (lambda (x y)
                     (irgb 0 0 (+ initial
                                  (* (- final initial) (/ x (- width 1))))))
                   width
                   height)))

(define horiz-green-blend
  (lambda (width height initial final)
    (image-compute (lambda (x y)
                     (irgb 0 
                           (+ initial
                              (* (- final initial) (/ x (- width 1))))
                           0))
                   width
                   height)))

Works dark-to-light and light-to-dark.

For Problem 2, Can we use supplied code?

Yes

For problem 2, mine looks kinda like a cat, but not as good as yours.

As long as it makes reasonable sense, it's fine.

Sam used something like (let ([p1 (+ 1 (- (max d1 d2 d3 d4) d1))])

Can you really have a distance of 500?

No

About how many different tests should we plan on for problem 4?

A dozen or so distinct tests.

Do we have to document supplied procedures?

No. If I take off later, remind me that I said this.

Even though we've identified approximately 1,289,131 mistakes on the exam ...

Yes, I will take more corrections.

Lab

• No writeup today.
• Yes, we will continue today's lab tomorrow.
• Yes, we will also start the "verifying preconditions" lab tomorrow.