IT1005

Lab session on week 5

About your Lab TA

• Name: Steven Halim (Indonesian)• Occupation:

– Full time teaching assistant– Part time PhD student

• Not yet professor, so just call me by name!• Want to graduate soon >.<

• My problem:– I am handling 5 lab groups this semester

• That means 5*~20 = ~100 students• 100 emails/lab submissions per week

To make life easier for me

• E-mail answers to: stevenhalim at gmail.com• With subject header:

– “IT1005-LabGroupID” “FullName”,• e.g. IT1005-7A StevenHalim

– I will ask Mr Gmail to sort your emails for me =)

• Try to submit your answers ONCE only– Do not submit again to fix some minor mistakes!

• Shorter (but correct) answers ~ better marks =)• Remember, I have ~100 emails/week !

IT1005 Lab Policies

Applies to Lab 2 onwards

Just some highlights on the rules posted by Colin

Lab Location

• Lab sessions begin Monday 11 Feb 2008.• All A groups are at SOC1/815 PC Lab 2.• All B groups are at COM1/114 Embedded Systems

Teaching Lab 1.• You can use your own computer/laptop• You can use the MATLAB clusters in FOE

– ChBE Clusters at E5-03-24 (24 hour access)– Check this link for other clusters that you can also use:http://www.eng.nus.edu.sg/eitu/about_us/aboutus6.htm

Lab Policies

• Lab attendance:– You are free to do the labs in FoE (or at home) instead of

going down to SoC1/COM1.– However if you have a question to ask, you can only do it

during the lab session.• Your tutor will be waiting for you during the session.• This means that you should at least look through the lab ahead of the

official session in case you need to see him/her.• Exception for me: you can email me, but the best way to explain is

hands on during the lab session.• Also with subject header “IT1005 – your question bla bla”• Try to post questions in IT1005 IVLE Forum first, especially if your

question is generic.

Lab Policies

• Lab Submission– Electronic submission via email to your respective tutors. – Your tutors will contact you via email ahead of time so you

know whom to submit to.– Your grades will be returned to you electronically as well.– For this, use my gmail subject labeling scheme explained

previously, ok!

You do not need to attend labs!

• MATLABs are available in FoE labs.• I was told that some of you also have MATLAB in

your very own laptop.• But…

But it is better to attend labs, why?

• I will review past lectures (~15m).– I will help you to keep pace with the lectures.

• I will discuss past lab questions (~15m).– Not just the answers, but also common mistakes, and side

topics around lab questions.

• I will discuss current lab questions (~15m).– Not the answers, but how to tackle them.

• I will ask stimulating MATLAB questions (~15m).• 2 hour lab: 1 hour interaction, 1 hour free & easy.

Review of Past Lectures

• http://www.comp.nus.edu.sg/~stevenha/myteaching

• Click “supplemental materials” for lecture.

Discussion about Lab 0/1

• You can now check your submissions in my website – Everyone can see each other’s marks/comments >.<– Sorry for that…– Special case for lab 0/1 only

• Next time, marks/comments will be sent privately– You send your report via email– I will read and reply your email, only you know the marks

Discussion about Lab 0/1-Part A

• Common mistakes– Changing the story >.<, strong penalty– Not really answering the question

• e.g. “arrive at lecture”, what lecture? what time?

– Too long winded, fine as long as logical enough• e.g. 10 large steps vs 3! (Note about human temporary memory)

– Funny story, just make me laugh, no penalty– Flat answer, no indentation, minor penalty

• You are all different =)

Discussion about Lab 0/1-Part B

• Common mistakes– Too long winded

Discussion about Lab 0/1-Part C

• Common mistakes or ‘mistakes’– Average ‘age’? We never say ‘age’ here!– Part i, ii, iii, and iv again! Too long winded– Indentation issue, variable naming issue– Matlab functions vs functions in the problem description!

– disp/sprintf vs say, ~= vs !=, ./ vs /, clear all? (not described)

– Stopping criteria must be -1, not <0 or anything else!– Excessive usage of comments >.<– Division by zero for extreme case :p (-1 at the start)– Slight error, how to correct the effect of -1?

Quick Test

• Simple test to roughly gauge your initial skills:– Convert this Decimals to Binaries: 10, 20, 32.– Convert this Binaries to Decimals: 101, 1001, 1005.– Tell me the actual value of: 1e2, 2e-1.– Write “Hello <yourname>” in MATLAB.– Compute: 234 / (80 + 2) * 72 – 189 \ 5 + 2 in < 10 seconds.– What is sin(pi)?– Create an array of size 4*5, containing all ‘1’.– [1 2] .* [2 1] =[3 4] [2 1]

Lab 2 – Starting Matlab

• Let’s follow the instructions!

Top Down Design

• A hands on…• Let’s solve this simple problem:

– Steven is a young schoolboy.– His mother gives him 25$ pocket money per week.– Steven spends his money wisely.

• By the end of each week, he usually has some money to be saved.• A random value between 0.0$ to 25.0$

– Steven wants to know his savings over one year.

Extra Materials

• How can you help yourself with MATLAB?– Visit MathWorks website

• Go to support documentation.• e.g. disp versus say, input, sprintf