Last 400 metres!

November 25, 2014

Last week, I did not submit a sLog. To be honest, I did not do anything for the course, besides starting on the assignment, so there was nothing to new to note.

To start, Larry gave the class some hints for Assignment 3. These were very helpful, and it alleviated a lot of doubt in my work, and also gave me some hints that I did not occur to me before. With this new knowledge, I will be re-tackling the questions, and hopefully will go a lot smoother than the first run.

I did not as well on Assignment 2. I focused too much on one question, which caused me to miss out on what should have been obvious mistakes. Had I took the time to thoroughly review them, the mistakes could have been easily avoided. Assignment 3 is my time to redeem myself!

Today’s lecture covered countability. The first example was a strange one, and seemed to go against what seems natural to us; size of the set of natural numbers equals the size of the set of even natural number. He explained that because we can map a natural number to a unique even natural number, the two set sizes must be the same (n to 2n). It makes sense, but it is still a foreign thought because we were talking about subsets earlier in the term, and the even numbers are clearly a subset of the natural numbers.

Larry also introduced the idea of countability. However,  I want to know decided that Natural and Integer numbers is “countable”? For every natural or integer number, there is always a higher natural number…so how can you conclude that it is ever “countable”?

And this new material is not in exam. Great. I was not hungry enough to stay awake as well!

And that is the end of the lectures for the term--

Maya.

O

November 11, 2014.

Lest we forget.

This week we received our term test 2 back. Although there were small mistakes, it was generally a good mark. I am glad I put in some effort to learn the proofs for the assignment. A small mention of the Assignment 3 was made. It is going to be like last time. “Just” need to find the trick.

Lecture continued on about proofs. It started with straightforward questions, but as it progressed, I got lost around the time where he wanted to disprove a statement about Big-O and Omega. He did not quite thoroughly go through each of the last two harder proofs, so I will have to go back and review those. I know when I go to do similar questions, although I have a vague idea now, like everything in this course, I will be scratching my head. I am not quite sure how and why he can arbitrarily let some function equal a certain function, but I will review that in due time….

When I thought lecture was soon to be a wrap, Larry introduced Computability. It is hard to see why it is important. Especially with my mind wandering since the the latter half of the proofs section, I was easily distracted. The individual sentences made sense, but I did not absorbed anything, and I have no idea what the purpose is and the idea behind halting, and non-computability. I will go over it slowly, like every other thing in this course.

Next lecture is final one?

Oh dear.

Toodles,

Maya.

Boo boos

November 4, 2014

During this past week, most of the my attention was concentrated on Assignment 2. Deciding whether Claim 1.2, and 1.3 was correct or incorrect was a long battle fought., I was constantly flipping between True and False all week. At the beginning, after working it out logically, I was very very sure that Claim 1.2 was False, although I did not know how to prove it on paper. However, as I was working through the problem to see if I can use math to solve it, it dawned on me that it was probably CORRECT. I started worked on that conclusion, but then I thought about it again, and I decided it had to be INCORRECT. This loop went back and forth many many times.

Looking at the Assignment 2 answers, I was relieved to know that my answer of Claim 1.2 being false, and 1.3 being true. However, because I focused so much on these two parts of the assignment, I did not really think the last 2.1, 2.2 through. The converse should have been false, but I had put as true. Thus is life. I need to make sure the “easier” questions are absolutely correct before I move on…

Today’s lecture was more or less a step by step approach to proving Omega. The steps were fairly structured, so it was easy to follow along. There were stark differences between the examples, which give a general standardized approach depending on the type of equation. Hopefully there will be a decently clear path on future questions.

Maya.

Note: It helps to be not sleepy in class

Double note: My apologies, I forgot that I did not post my sLog for last week until today.

Omega

September 28, 2014

I am starting to wonder what I will do for Assignment 2. Between trying to figure out how to indent in ShareLaTeX (unsuccessful), and trying to figure out the details to the proofs, I have some doubts. I had an opportunity to talk to the professor about the assignment and proofs in general, so I have a better idea of what to do; hopefully it’ll be sufficient to pull me through.

All that aside, this week in lecture, the big O and Omega was covered. Like most materials for the past weeks, although I understand it, but do not understand it. When choosing c/B, the inaccuracy makes me anxious as well: As long as it’s aaaany number greater than X, or annnny natural number greater than Y, etc.. And is O(n^2) Omega(n^2) always going to be compared to (n^2)? I do not know. I was particularly hungry tonight, so my attention span and effort levels are diminishing quite quickly.

As a side note, we watched a slow animation of insertion sort. Twice. WHY!? And as a bonus, the slide had a mini version of the animation on the side.

Soon afterwards, the class participated in an activity: Penniless stacks. I was too tired and hungry so I did not actively try to solve the problem.

No, I will not discontinue to be paranoid.

Maya.

Forgotten

October 21, 2014

Larry opened the lecture with an announcement that the assignment has been posted, but to manage our time, because Test 2 will take place the day after. I am glad he mentioned that, because I definitely forgot about it. Earlier, I took a peek at the assignment; it is all proofs (not that I was expecting anything else). I hope I can get comfortable with proofs before the assignment and test comes due…

As the lecture moved on to the next material (more proofs), I still am not sure, how much proof is enough? In PHL245, the tools to prove is limited, making the options limited and straightforward (if you can find the correct path). So far, the proofs in CSC165 could be endless, and less structured. Larry also mentioned there is a lot of practice questions that have been posted. I am planning to attempt those.

The second half of class was about Algorithms. Although the material was straightforward, it was interesting to see all the thoughts that is put into code I passively write for class.

Off to find time to practice,

Maya.

Proofs

October 14th, 2014

There’s no tutorial this week! I will be able to go home earlier to feed my dog!

In lecture, it was a continuation of proofs. Started with a simple example, which was very easy, and helped me understand the structure of a proof.

However, the professor re-introduced a formula:

>0, >0, x R, | x -2 |<, | x2-4 | <

I had a hard time coming to understand this, and only after the explanation was given, did I have any comprehension of it. Larry said to disregard the complicated-looking formula, and not be intimidated by the greek letters. But this is not about the greek letters! I may have mentioned in a previous sLog, but I am not confident I can solve this proof if something other than this question were to come up.

As we worked through this proof, I may or may not have understood. I can only hope that many many proofs will be done throughout this course, so I can finally say “I GET IT”.

As a side note, I am very impressed with the amount of people who received 100% on their first term test! Too bad I was not one of those, but still very impressed!!

Until next time,

Maya.

I PASSED

I PASSED
WOHOO