CSC 151.01, Class 09: Writing Your Own Procedures, Continued

Overview

• Preliminaries
  • Notes and news
  • Upcoming work
  • Extra credit
  • Questions
• Lab
• Questions and reflection.

News / Etc.

• New partners!
• Quiz 1 returned.
  • Note that (irgb-lighter c1) does not modify c1. Instead, it returns a new color.
  • That should not be surprising. You would not expect (square x) to change x.
  • Some of you missed that since the result of compose is a procedure, it implicitly has a parameter. For example, we would describe the result of (define irgbll (compose irgb-lighter irgb-lighter)) as “A procedure, (irgbll color), that computes (irgb-lighter (irgb-lighter color)).
  • That means that the solution to problem 1 should have been something of the form (define myfun (compose ....)).
  • Your number at the top of the page looks like 8 + 1 = (9)
• Our graders’ account got locked last night. (Even I don’t have access right now.) I’m not sure where we stand in grading.
• Exam 1 will be distributed on Wednesday.

Reminders

• I’m always happy to (try to) answer questions via email. There is no need to apologize when sending me questions. If I take too long to answer, send another email (or even text, if it’s a reasonable hour).
• We have tutors available Sunday through Thursday evening from 7-10 p.m. in Science 3813/15.
• We have mentor sessions on Wednesday and Thursday evenings from 8:00-9:00 p.m. in the CS Commons. Wednesdays will be more Q&A, Thursdays will include sample quizzes.
• I run review sessions on Thursdays at 9am in this room.
• We have individual tutors available for those who take advantage of the above and find that it’s not enough.
• I’m happy to add anyone in this class to the csstudents mailing list.

Upcoming Work

• Assignment 3. Due Tuesday!
• Reading: Output in Scheme.
• Reading: Simple input in Scheme.
• Lab writeup: Exercise ???. Due Wednesday before class.

Extra credit (Academic/Artistic)

• CS Table, Tuesday, 7 Feb 2017. Something on privacy. See email.
• Thursday extras, Thursday, 9 Feb 2017, 4:15 p.m., Science 3821: Something on computer graphics (visitor from UMN). Let me know if you want the email.
• Scholars Convocation, Thursday, 9 Feb 2017, 11:00 a.m., JRC 101.

Extra credit (Peer)

Good things to do

Questions

How do we cancel appointments?

• Option 1: Click the cancel appointment link.
• Option 2: Email Sam and say “I’d like to cancel my appointment.”

How firm is the two-day limit on extra credit?

• Not very. Just write it up soon.

Lab

• Please say “we” rather than “I”
• Writeup: Exercises 4, 5, and 6.
• Please make sure to do the preliminaries! (Particularly when it says to download code.)
• How do we know when the page was last updated? It appears that Firefox has removed that option. You can just use the copyright date and the date you visited it.

Writeup

Write up exercises 4, 5, and 6 from the lab on procedures.

Send your solution to csc151-01-grader@grinnell.edu.

Title your email CSC 151.01 Writeup for Class 9 (YOUR NAMES).

Questions and reflection