1. CS123 Engineering Computation Lab Lab 4
Bruce Char
Department of Computer Science
Drexel University
Spring 2010

2. Administrative Notes
Please contact your instructor immediately if you are eligible for extended time for the Proficiency Exam
Please also review your bbVista Lab and Quiz grades and report any discrepancies to your instructor
As with cs121 and cs122, there will be an opportunity to earn a 2% bonus for submitting a student evaluation. Details to follow!

3. Proficiency Exam Preview
Same logistics as in cs121 and cs122
Proctored format
Two quizzes (about 25 and 70 minutes)
Sign-in and score verification
No access to bbVista – will have access to all course site materials
To be conducted during week of May 30 (week 10) in class for your regularly scheduled lab session
Note – Monday labs will be held on 6/6 (last day of classes) as opposed to 5/30 (Memorial Day)
Practice – week of May 23 (week 9)
All 4 quizzes taken throughout the term will be re-posted on Tuesday, 5/24 – note that quiz 4 will take place during week 9
A special quiz containing some problems not included in regular quizzes will also be issued – these questions are candidates for inclusion
Lab solutions will be posted on bbVista
Full quiz week (9) CLC coverage – Monday through Friday
Graduating seniors are NOT exempt from the proficiency exam!!

4. Lab 4 Overview Based on materials from Chapters 21 and 22 readings
Chapter 21 – Calculations that return true or false
Use of boolean expressions with a programming API
Chapter 22 – Review of course goals and objectives

5. Lab 4 Overview Lab 4 outline – 5 parts
Part 0 – introduction to software mechanics and features
Part 1 - move car in a square
Part 2 – bump car back and forth between 2 walls
Part 3 – find gap in a wall and proceed to target
Part 4 – find the nth gap in a wall and proceed to target

6. Lab 4 Maple Concepts Discussion and Demo
Application Programming Interfaces (APIs)
An industry standard term for a package of procedures that simplifies the process of writing code for a particular purpose
An API usually provides a set of functions (user interfaces) to create applications
Maple provides an API for many common mathematical and computation tasks
Plotting, calculus, trigonometric functions
Why they are important
Entire courses on software design and reusability
Bottom line – give programmers a way of easily writing code for a particular platform
Encourages rapid development, saves work

7. Lab 4 Maple Concepts: Discussion and Demo
Car Simulator API
An API written by the course staff that enables you to animate and simulate car movement in conjunctions with walls, barriers, etc.
This simulator ignores forces of friction, focusing on the logic of controlling the (directional) movement of a car

8. Lab 4 Maple Concepts: Discussion
Car Simulator API – 4 key functions available
move(x)
Moves the car forward (in the direction it is currently pointed) x squares
Turn(d)
Turns the car d radians to the left
Turn (Pi/2) makes the car turn directly to the left
Turn (-Pi/2) makes the car turn directly to the right
The turn is always relative to the current direction of the car
isTouching(d,’stateOfCar’)
Returns “true” if the car is touching some object in the direction d radians above (PI/2), left(Pi), below(-PI/2) or right (0)
Direction d is always absolute in terms of the X-Y axis
It is OK to use ‘bt’ for ‘stateOfCar’

9. Lab 4 Maple Concepts: Discussion
Car Simulator API – 4 key functions available
getCURRENTLOCATION()
Get the current state of the car, which is a list with:
[x, y, dir, state]
[2, 0, 0, CarSimulation:-CARNORMAL]

10. Lab 4 Maple Concepts: Discussion and Demo
Car Simulator API – flow of lab
There are 4 sections to Part 0 (each contained in it’s own work sheet) and 4 problem work sheets associated with Parts 1, 2, 3 and 4
You must open and perform the tasks for each of these work sheets in the order presented in the lab description
It is especially critical to 1st open and run the Part 0 tutorials. It loads the Car Simulator API software that is needed throughout these exercises

11. Lab 4 Maple Concepts: Discussion
Part 0 exercises
1st copy the zipped file from the course site and then unzip (MAC may automatically unzip for you)
Open the Maple worksheets from the unzipped files as per the lab description instructions
Follow the directions in each work sheet - study the logic in each code edit region, run the code and review the output
Note that some regions produce an animation of the car’s movement

12. Quiz Week (9) Activities
Quiz 4 will be released on Friday (5/20) at 6 PM
Deadline: Wednesday (5/25) at 4:30 PM)
Makeup quiz – from Thursday (5/26) at 9 AM through Sunday (5/29) at 11:00 PM
30% penalty
No Pre-lab quizlet
Be sure to visit the CLC for quiz assistance
Practice week for Proficiency Exam
Will be posting practice quizzes on Tuesday, 5/24
Exam to be conducted during week of May 39 (final week of regular classes)