CSC151.02 2016S, Class 26: Recursion Basics, Continued ====================================================== * 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](../readings/preconditions-reading.html) * 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 * Due before class on Friday. ### Extra Credit * Send your reports to 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.