Introduction to Computer Science

Lecture 3 / PS1 Start

2010-03-08T23:22:39Z

In order to keep this straight in my head, I've collated a calendar with the start/due dates of the problem sets and the time spans of the lectures. The calendar has links to the major resources (PDFs, PY templates, lecture videos). As we complete the problem sets, I'll add links to the solutions. Of course, I'll also post the links here on the key dates.

Links:

Lecture 3 (spans March 8–21, 2010):
- Common code patterns: iterative programs (video)
- Handout (PDF)
PS1 (due March 21): Computing prime numbers, product of primes (PDF)

Update on reset

2010-03-04T23:25:02Z

From the responses, I think we might be safe to start at lecture 3 and do 1 lecture every 2 weeks. If everyone is cool with that, I'll create a schedule that begins on Monday, March 8, and we'll start from there.

If there are only four of us...

2010-02-28T18:40:13Z

...I think we'd be safe making our own rules and setting our own pace. If you've read the comments to the last post, you know where each of the others stands. I've watched and read through the lecture 8 material and finished PS4, but I don't mind back-tracking if that's beneficial to everyone.

So...what say you all? Would you like to back up to an earlier lesson and take it at a more relaxed pace? If so, where would you like to start? From the beginning, or pick up at lecture 2, as everyone seems to have watched the first one? If you'd rather not back up, would you be willing to wait until everyone can catch up?

Re: pacing, how would you like to proceed? The current schedule is based on one lecture per week. We could do one every two weeks, which would work out to approximately one problem set per month. Would that be better?

One last thing: We might be able to help each other better if it's clear what each person hopes to get out of the course and if/where you may need specific help.

To alleviate the shyness factor, I'll begin: I wanted to follow this for three reasons: to pick up Python; to get a feel for the MIT OpenCourseware (because I want to take some others); and to see what sort of topics I might want or need to include—and exclude—from a programming concepts course I'm developing for non-programmers. As for help, I'm okay so far, though I've had to dredge up some math I haven't used in a while.

How 'bout you?

Question re: Class Calendar/Schedule, Check-in

2010-02-24T15:21:47Z

As winterthunder mentioned, I've agreed to take over the admin duties. However, as I'm in the middle of two major projects, I really need to relax the schedule a bit. Does anyone have any objection to this?

Also, I'd like to get an idea of how many are still following the class and your status—whether you're up-to-date, and if not, where you are in terms of the lectures, readings and problem sets.

Hope to hear from everyone who's still following!

Lecture 8 and Quiz 1

2010-02-23T01:20:59Z

My apologies, I didn't get to posting this yesterday. This will be my last post. aranthe will be posting shortly to get your opinions on tweaking the schedule a bit, so he/she can make the class work with her schedule.

Several weeks ago, we also opted to do the quizzes (of which there are three), and the first one is supposed to go up today. It appears that they've been nice enough to give us solutions as well as problems, so I'll put them both here and you may do with them what you see fit. :D

Quiz 1 and Answers to Quiz 1

( Lecture video below the cut. )

Lecture handout is here

Enjoy the rest of the course! Hopefully someday I'll be able to get back and finish it. In the meantime, look out for my new shop, Written Insight, which will launch on Etsy in the next couple of weeks, and will hopefully pay my rent when I go back to grad school in August.

Readings and PS4

2010-02-19T23:40:11Z

As per my last post, I have not read these nor done the problem set. Any more volunteers to take over or possibly tag team with aranthe? Doing these posts doesn't require comprehension of the material (as some of my discussion questions have indicated, I'm sure), it just requires that you do the readings and watch the lectures on schedule.

Readings:
Analysis of Algorithms
Wikipedia Binary Search Algorithm with the focus on the Implementations section.
Asymptomatic Notation (PDF)

Problem Set 4 (PDF)
Supporting File

Call for Volunteers

2010-02-17T03:37:35Z

At last count, we had about 10 people still following along. I need to pass off the group leader position to one of you.

My hours at work increased two weeks ago. That's all well and good, since I need the money, but I'm also launching a small business on the side and something's got to give. I can't keep up with even the 4-5 hours a week I'm spending on readings, lectures and problem sets.

I'll be happy to send the posting schedule to whoever wants to take this over. I'll also continue to post reading links and lectures until someone volunteers, but there will be no discussion questions from me because I won't be reading or watching.

I've enjoyed the parts of the class I've managed to complete, and I wish you all the best of luck in finishing up.

So... any volunteers?

Lecture 7

2010-02-15T03:27:46Z

Another slightly shorter lecture today, and we switch professors in the middle. \0/

( Video under the cut )

Readings

2010-02-13T03:24:20Z

So, this set of readings is for Lectures 7 and 8. Therefore, for a medley of reasons but mostly because the Opening Ceremony is on TV, I'm planning to do the readings over the next few days. I'll re-post the links again next Friday, along with any discussion questions I can come up with.

For your reading pleasure:

Asymptomatic Notation (Note: PDF)

Recursive Implementation (Note: links to middle of page, as per reading instructions)

Analysis of Algorithms

Enjoy!

Lecture 6

2010-02-08T02:38:40Z

So, who thinks the other professor was better? I'm finding this guy harder to follow, though I did catch that computers can be wrong and paranoia is good.

Paranoia, paranoia everybody's coming to get me...

Er. ( Lecture video under the cut. )

I have to say, I understand the whole lists, appending lists, concatenating lists idea, but I'm not following the code. For the universities bit, what are all the raw_inputs there for? Is the for loop just there to show that appending lists is messy? And which line is the concatenate? Is it "Univs = Techs + Ivys"?

(Class handout is here, and I've pasted the relevant code section under the cut.)

( Click for the code! )

Solution to ps3

2010-02-08T00:44:45Z

As always, please feel free to critique my code, ask questions, or post your own code in the comments. I did problems 2-4 using iterative solutions, so I'd be especially interested in seeing recursive solutions for those problems. Also note that several of these functions call each other, so they need to be placed in the same file.

( Solution to ps3 )

Readings and PS3

2010-02-06T04:32:19Z

As of this week's readings, we're over halfway done with all the readings for the course! \0/ It gets a lot lighter, reading wise, from here on out, and I have to admit to being a bit relieved. Maybe now I'll actually manage to do the problem sets before I put up this post...

Anyway, for Lecture 6 we're supposed to read through Chapters Eight and Ten, using part of the Python Tutorial as a reference. I have one question to toss out for discussion. I know the long form came up in lecture last week, but I didn't realize until I did today's readings that you could force Python into the long form. I just thought it was something that Python switched into when the numbers got too long. Why would you want to start your calculations in long form? Wouldn't it be easier to let Python do it on its own?

View Poll: #2228

Now, I'm still working on PS3 myself, and given that I'm fast approaching the point of garbled language exhaustion, it ain't happening tonight. Any volunteers to put up their code?

Lecture 5

2010-01-31T23:28:09Z

Hello hello hello!

Lecture five was a short one, and we did not find out about the mysteries of the Newton method. Based on the handout, it looks like they planned to go over it, so I guess that comes next week.

( Lecture video under the cut )

Anyway, without the Newton method, this lecture was mostly stuff I understood from the readings. What about the rest of you? Anyone guess the bug in the squareRootBi code?

Readings

2010-01-30T02:45:04Z

No problem set this week! \0/

Instead, we get two readings to mull over: Floating Point Arithmetic and Newton's Method. Now, the first one I was all right with. I can't envision a situation in which I could possibly care that Python rounds to only seventeen significant digits, but hey, I guess it's good to know these things. But what does Newton's method have to do with programming?

On a side note (and out of curiosity on my part), we started out with 30 something people following along. How many are still with us as we go into the fifth lecture? Stand up and be counted!

Lecture 4

2010-01-25T02:56:30Z

( Video behind the cut )

This lecture is pretty code heavy, so make sure you have the PDF available for reference. Also, jetamors has graciously put up the solutions to PS2 here. I am being a good student and ignoring them until I've finished my own code. :D

Solution to ps2

2010-01-25T01:23:08Z

Putting my code for ps2 behind the cut. Please feel free to critique it, ask questions, or post your own code in the comments.

( Solution to ps2 )

(Also a question: when I have a really long print statement like this, how do I break it up so it doesn't stretch the screen? I looked through some of the documentation, but I couldn't find anything on it.) ETA: Figured it out and updated my code :)

Readings and PS2

2010-01-24T01:31:00Z

Hello everyone!

The readings weren't too bad this week, I thought. What about you guys? I'll need to go back and re-read some parts of Chapter 3, but my notes this week didn't look like I'd upset red ink over them. :)

Any questions, feel free to toss them out in the comments, as usual.

And about that problem set...

View Poll: Problem Set Two

Now, I'll admit that I still haven't gotten to the problem set, so I'll be tackling that along with the lecture tomorrow. In the meantime, does anyone want to volunteer to post their code under a cut?

Delay in your regularly scheduled reading post

2010-01-23T02:28:10Z

I'm sorry, but the reading/PS2 post is going to have to go up sometime tomorrow, unless someone who's finished it wants to put it up for me. It's been a hellish week, and even if I can finish this health insurance application tonight, I'm not going to be in any mental condition to read, code and comment. Better all around if I come at it with a full night's sleep.

Lecture 3

2010-01-18T00:23:07Z

Well now, PS1 would have been a lot easier if I had watched this lecture first. I even went and checked the schedule again after I watched it, thinking that I must have misses something and gotten the due date wrong on the problem set. But no, it appears the problem sets are due the day of the lecture, and then the lecture hammers home the info in the problem set. Methinks, since I control when I "go" to lecture, that I'll be watching prior to doing my homework in the future. :D

Anyway, thanks to the very helpful explanations of jetamors and aranthe, I had no trouble understanding this lecture. What about the rest of you?

( The video is under the cut, as is a link to the class handout. )

If you haven't had a chance, go and vote in the poll from the PS1 post and have your say about whether and when we do the quizzes. Also, if you're confused, there is a *lot* of information in the comments on the last two posts! Read through that, and feel free to ask if you have more questions. :)

Solution to ps1

2010-01-16T07:09:25Z

The solution I wrote is behind the cut. Please let me know if you have any questions about the math or the code itself, or feel free to share your own solution in the comments.

( ps1.py )

Readings and PS1

2010-01-16T03:01:41Z

Hi everyone!

First, class business... I went poking around the website, and I found a suggested schedule for the problem sets. They actually correspond to the lectures, imagine that! Anyway, armed with this new info, I've made some tweaks to the problem set schedule.

( They're below the cut, if anyone's interested. )

I also discovered that there are three quizzes associated with this course. So I'm putting the question to you all - do you want to do them?

View Poll: Quiz? What Quiz?

Okay, that's out of the way, on to the readings.

I gotta say, this week kicked my ass, and these readings were right there with work and family issues, putting their prints on my bum. The wikibook chapters in particular just are not working for me. Is anyone else having that issue? My notes on those chapters are scattered with big red question marks and underlines with "What does this mean??" written off to the side. Part of this, I think, is that I really don't do numbers. I had to go look up the definition of a prime for the problem set...

Anyway, I've got some questions to toss out for discussion.

1- From the Data Structures reading, what are stacks and queues and why do we care about them? The reading just goes, 'This makes it easy to use lists in stacks and queues, whee!' (Or at least, that was my impression...)
2- From the same reading, why is it useful to be able to unpack a tuple?

Anyone else have questions for the class? This set of readings certainly provides fertile ground for questions. All of section 5.8 of the Data Structures had me going, "Bzuh?" And I just gave up on the wikibook...

View Poll: Who rocked problem set one?

Now, aranthe has generously posted answers to some of the exercises in the readings. Anyone want to volunteer to do that for PS1?

if Exercises in Programming Python, "Conditional Statements"

2010-01-15T20:39:05Z

I've annotated the code fairly liberally, but if you have any questions, just ask. I'll be happy to explain anything that seems confusing.

I just realized that in an effort to make Exercise 1 less boring, I included some extra print statements that weren't required. To avoid confusion, I've replaced my first solution with a simplified one. For those who are interested, I'll post the embroidered one in a reply to this thread.

( Exercise 1 sample solution (edited, simplified). )
( Exercise 2 sample solution. )
( Exercise 3 sample solution. )

Lecture 2

2010-01-10T21:54:16Z

All right! Hopefully we've all successfully completed Problem Set 0 and are ready to tackle Lecture 2. Note that there is a handout associated with this lecture, and having it printed out before starting is a really helpful thing. Not that I had to stop and print it in the middle of lecture or anything...

Also, since our problem set numbers started with 0, I'm going to put up a post for PS1 this Friday. From that point on, problem sets will go up every other week.

( The lecture video is embedded under the cut )

I had one problem with this lecture, and I'm hoping you all can facilitate a light bulb moment. The code example with x, y and z, the fourth one down the page... I can't figure out what the bug was. Is it just because the statements aren't indented, or is there something else?

Readings and PS0

2010-01-09T01:26:58Z

All right! Looking at my schedule for the coming weeks, I think I'm going to add a readings and problem set post on Fridays, just to keep them separate from the lectures and to give everyone time to digest and discuss the information before we dive into the next lecture. (This will also give me an extra kick in the rear mid-week to get everything done!)

Thusfar, I've read through chapter 1 and chapter 2 of How to Think Like a Computer Scientist, the variables and strings and input and output sections of Python Programming, and the variables tutorial on Pythonista. They're a bit repetitive, but repetition is good for my brain! If you're a visual learner, do the tutorial on Pythonista first, because there's a really nice series of images there.

Out of the readings, the only thing that gave me pause was the minutes since midnight program in Chapter 2. I'm not sure exactly why... I didn't define hours and minutes when I first ran the example, and then after defining them it seemed a bit useless to write a program that only gave the correct answer at that exact moment. (Anyone watch Alice in Wonderland as a kid? That scene where they're cleaning the attic - "This old clock; it tells the right time twice a day. As for the rest? While, maybe not...") Regardless, I ought to go back to that when I'm not tired and trying to do all the readings in one chunk. Did anyone else have trouble with that one, or with anything else in the readings?

And then, PS0! As smc1225 graciously pointed out, you have to open a new window to write your code and then run it. This link, which she (guessing gender from the list of feeds on your profile, smc1225; my most humble apologies if I'm wrong) found when the November group went through PS0, is massively helpful.

So, who's finished PS0? I can't create polls, apparently, but let's report in on our successes and mistakes before we plunge onward into lecture 2!

Edit: Oh, wow, someone gave me paid time! Thanks, oh anonymous benefactor!

Edit 2: Ok, it appears I'm not allowed to insert polls into pre-paid time posts. But, in the future, there will be fun with polls! :D

Lecture 1

2010-01-03T20:42:19Z

All right! Computer science skillz, here we come!

If you haven't already, take a look over at this page and make sure you have the correct version of Python installed on your computer. Remember, if you install 3.0 the code you write in this course will not be compatible.

Lecture 1 video is here, and covers definitions and other introductory things. In an ideal world, I would have watched it already, but it's currently playing in another window while I multi-task, and I didn't want to wait any longer to put this post up. It seems basic thus far, but I shall edit this post if I come up with any questions. Also, feel free to comment with anything that doesn't make sense to you. We have over 25 people following along and we're all beginners, so we should be helping each other out. :)

Edit 1:

Ok, I've watched the lecture, and aside from not being able to see what he's typing on the computer screen, I'm feeling pretty good. I'm going to take some time over the next few days to dig into the readings and see if I can't get an idea of what was on the screen.