Exam 2 Topics
CS145: Images and Imagination, Spring 2014

This exam will be closed book.

Suggestions:

• Practice (among other things) problems on earlier exams
• Review class notes and exercises.
• Review lab work.

Topics

• Functions:

  • This builds on our earlier work
  • Modularizing code using functions.
  • Functions make it simple to use the concept of "Stepwise Refinement" where you solve a problem by breaking it into subproblems and solve the subproblems, one at a time.
  • Review Lab 3: Frieze Patterns. Stepwise refinement was used to implement the different frieze patterns.
  • Scope of function parameters - see Example

• Transformations

  • Review the use of transformation in Lab 3: Frieze Patterns
  • Translation, scale, rotate - order of operations matters!
  • What is a stack (LIFO - Last-in, First-out)
  • The Matrix stack. See Basic Example and Example with looping.
  • Controlling the pivot (fixed point)
  • Commutivity of transformations - when does the order matter and does it not.

• Trigonometry

  • Review coding exercises in Lab 4: Making Waves and Circles.
  • Review Lab 4 written exercises. See solutions here.
  • See Online: Trigonometry
  • How are sin and cos defined? How do they relate to the unit circle? See Greenberg demo.
  • What is the graph of y = shift + amplitude*sin(frequency*x + phase).
  • What is the relationship between sin, cos and tan?

• 1D Arrays

  • Review Lab 5: Bouncing Balls
  • Declaring arrays
  • Initializing arrays
  • Working with arrays
  • Arrays and loops
  • Accessing arrays

• The material is cumulative! The focus of the exam will not be loops or if-else statements, however, you may encounter these on the exam as they relate to the topics above.

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