hw01
intro; scheme warm-up

Due Sep.~~07 (Mon)~~09 (Wed) (hardcopy, and on WebCT). Your name and the assignment-number must be in a comment at the start of the file. Update: In class Monday we'll talk about test-cases (and, we'll emphasize not-repeating-code). However, I encourage you to finish as much as you can by Monday's class. Hw02 will still be due next week on Monday. Also, if any test-cases don't pass, say as much in a comment at the start of that problem.

Note that some of the reading questions originally included here have been deferred for a week or two, for those who are still awaiting their textbook.

The exercises below are from the (free, online) book How to Design Programs. In DrScheme, set your language to “Beginning Student”: Language > Choose Language… > How to Design Programs > Beginning Student.

(5pts) 2.2.1. (Three test-cases required; we'll discuss Monday.)
(3pts) 2.4.1 [Just report the error message, explain in a few words, and give a fixed version.]
(15pts)
- 3.3.2. (Copy helper functions from the book's §2.2)
- 3.3.3. (Cylinders have tops and bottoms.)
- 3.3.4. (Don't forget about the top/bottom of the pipe.)
Do not repeat any code; call an existing function instead. (For example, there should only be one function in your entire code which multiplies pi by a radius.) If you create the right helper-method for 3.3.3, then 3.3.4 will be pretty easy to implement.

At least two test cases required for each (at least one non-trivial). For inexact (floating-point) calculations, check-expect isn't quite what we want; instead use check-within with a delta of 0.0001 or so.

To experiment with functions-which-create-and-handle-images in drscheme, select Language > Add Teachpack…, and select the teachpack “universe.ss”. Then you should be be able to evaluate each of the following:

(rectangle 80 20 'solid 'blue)
(circle 20 'solid 'red)
(ellipse 80 20 'outline 'orange)

(overlay (rectangle 80 20 'outline 'blue)
         (circle 20 'solid 'red))
; Think of 'overlay' as being "addition for images"

; overlay with an offset:
(overlay/xy (rectangle 80 20 'outline 'blue)
            30
            10
            (circle 20 'solid 'red))


; If you want to explore documentation:
;   In drscheme, position the caret on a function-name
;   like 'overlay/xy', and hit F1.

Write a method which takes in a size, and returns an image of a donut. (Mmmm, doughnut.)
Write a method eye which takes a size, and returns an image of an eye.

Examples:

You don't need check-expects for these.

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hw01 intro; scheme warm-up

hw01
intro; scheme warm-up