Held: Friday, 8 April 2016

Back to Outline 35 - Iteration. On to Outline 37 - Pairs and Pair Structures.

Summary

We consider Scheme's random procedure, how one might use that procedure in writing simple simulations, and how the procedure can be used to generate "unpredictable" images.

Related Pages

• Reading: Random Drawing
• Lab: Random Drawing
• EBoard 36 (Source 36)

Overview

• Random art.
• Why use randomness.
• The random procedure.
• Simulation.

Administrivia

• Continue partners.
• I will continue to bring you food (or food-like substances) until I am caught up on grading.
• Yay! The College got money.
• Friday PSA.

Reminders

• Office hours this week
  • See http://rebelsky.youcanbook.me.
  • Ask me about other available times.
• Tutor hours
  • Sunday, 3-5 p.m.
  • Sunday-Thursday, 7-10 p.m.

Upcoming Work:

• Reading for Monday:
  • ...
• Lab Writeup:
  • Send email titled CSC 151 Lab Writeup 36 (Your Names)
  • Do not include the underscores.
  • Send to CSC151-02-grader@grinnell.edu
  • Due before class on Tuesday.

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

• BAX TODAY, 4pm, Bucksbaum.

Peer

• Fun Japanese Spring Festival TONIGHT at 7pm. Origami and food!
• Game Dev Class Demos, Monday, 2-3 pm, DLab.
• Is anyone presenting in next week's celebration of student scholarship?

Miscellaneous

• Pioneer weekend. THIS WEEKEND.
• Host a prospective student.

Regular Peer

• Social Dance Workshop Tuesdays 7:00-8:00 in Bucksbaum Dance Studio
• Post-break ExCo on British Politics Wednesdays at 8:00 in JRC 203.
  Just show up; you don't need to sign up.
• Pun club Saturdays at 4pm in Younker
• Electronic Potpourri on KDIC Fridays at Five
• Space Odyssey KDIC Fridays at Six
• Bollywood, Fridays, 7:30-8:30, Younker
• Effective Altruism club, 2:30-3:30 Sundays in JRC 226.

Misc

Far in the Future

• Lords of the Flies, April (maybe the 22nd).
• Adaptation of Rushdie's East West. Early May.

Other Cool Stuff

• Mission Creek Festival in Iowa City has some cool talks about technology and the arts, http://missionfreak.com.

Questions

I really want to take the awesome-sounding one-credit course entitled "Social Justice Issues Influencing American Business". But it overlaps with 151. Can I miss four sessions without penalty?

Yes, provided you make up the labs on your own.

I'd really like to take CSC 207 in the fall. Is it possible to do 161 over the summer?

We provide two alternate tracks for 161 over the summer. Neither counts toward the 32 credits in the major, but they do allow you to go on to 207.

You can take the Harvard CS 50 course on EdX. https://www.edx.org/course/introduction-computer-science-harvardx-cs50x

You can use the pre-robots version of CSC 161 and have me give you a test at the end of the summer.
< http://www.cs.grinnell.edu/~walker/courses/161.sp10/>

I'll do my best to answer questions in either context.

We have about a 50% success rate for either option.

Is grading done yet?

No. It appears that all the signs that Minna posts about sleep are correct.

Monday?

I certainly hope so.

Have people started asking good questions about the exam?

Yes.

Can you go over some of them?

Maybe.

I need more than one consequent in an if statement. What do I do?

Use cond or when.

I don't need an alternate in an if statement. What do I do?

Use when.

Can I use list-drop or list-take in solving rdc or rac?

No.

Randomized Images - The Theory

• Non-mainstream art philosophy: The images that come from random processes (or from nature) can be as interesting as the images that come from artists who intentionally plan the canvas.
• One important movement: Dada. (Early 20th century; also a reaction to facism and industrialization and ...)
  • An example: Tristan Tzara's "How to make a Dadaist Poem"
• Disclaimer: After creation by random processes, some filtering of good from bad often happens.
• Disclaimer: Many of the random processes still include some artistic intention.
  • Jackson Pollock's painting style provides an interesting combination of intent and randomness.
• Modernized/computational suggestion:
  • Randomized processes can provide inspiration
  • The ability to constrain some aspects of the process can provide a new mechanism for creation.

The random Procedure

• Scheme helps us by providing a (random n) procedure.
• n must be a positive integer.
• random returns an integer between 0 and n-1, inclusive.

Randomized Images - Practice

• Many of the procedures we've written or used have numeric parameters.
• Those parameters can be generated "randomly".
• Many of the procedures we've written take one of a restricted number of inputs (e.g., there are only so many brushes).
• Those inputs can also be selected "randomly".
• Demo: Randomizing the brush

Other Uses of Randomness

• We often use randomness in simulating unpredictable events, such as the rolling of an unbiased die.
• More requently, such randomness is used in larger-scale simulations.
• We'll stick with images, though.

Lab

• Do the lab