Old (06-07) TIK Computer Science at Jarvis C.I., Toronto

Week of May 14: Program Tracing / Arrays

2007-05-16T10:47:00.000-04:00

This weeek we finish our little unit on program tracing. There will be a test, requiring you to trace and give the output for 5 programs.

From the Turing textbook, we introduce the concept of arrays. Arrays enable you to create large numbers of related variables and to process them as a group.

Week of May 14: - Program Tracing / Arrays

2007-05-16T10:39:00.000-04:00

This week we finish program tracing, ending with a test.

From the Turing textbook, we begin Chapter 14, Arrays. Arrays are a special data type that enables you to create large numbers of variables and to process them as a group.

POSTPONED TO NEXT WEEK - Test on Turing, Ch.11 will be first class next week

2007-04-30T09:33:00.000-04:00

Because of conflicts with a music field trip, the programming test on Chapter 11 (Handling Strings) is re-scheduled to the first class of next week.

As usual, the questions will be modeled on the questions at the end of the chapter (excluding those we've labeled as "Optional. For students wanting a challenge") and the questions in the "Extra Exercises" file.

Next week we will continue into Chapter 12 of the Turing textbook.

Practise string handling with real text

2007-04-29T08:57:00.000-04:00

As you practise handling strings in Turing, it's more fun to use "real" text. One great source of full-length books in ASCII format is www.gutenberg.org.
Now that you know how to access external files with your programs (Ch. 10), you can write programs to analyze a famous book and calculate what percentage is vowels, find the average length of a sentence, find the longest word, encrypt the text by replacing characters - all kinds of interesting things.

(Amaze your English teacher by announcing you know the exact number of times the words "love" and "hate" appear in Romeo and Juliet. Yowzah! Replace every other word in the whole book with your name and see if it is still readable. Change all the i's to 1s, the b's to 6s, the e's to 3s, the s's to 5s. Go crazy.)

Remember that the text should not contain any quotation marks, since Turing will interpret them as signs for tokens. Before you use the text, do a quick Search and Replace in Notepad to replace all the quotation marks (") with apostrophes (').

Substituting One Pattern for Another (Ch. 11)

2007-04-19T07:56:00.000-04:00

Let's say you want to change the string "music" to "muzic".

The method Turing uses is to separate the first part, to just before the "s" for which you want to substitute a "z", add the "z", then add the rest of the string that followed the "s". In other words, like this:

You get the first part, "mu", by taking the string from postion 1 until index (string, pattern) minus 1. Again, as we did in the previous exercise, let's simplify by creating the variable pos : int := index (string, pattern). So separating the "mu" of "music" looks like this:

word (1 .. pos - 1

We add the "z" like this:

+ "z"

and we finish by adding the part of the string AFTER the "s" like this:

pos + 1 .. *

In summary, the complete line to substitute the "s" in "music" for a "z" is

word: = word ((1 .. pos -1) + "z" + (pos +1 .. *))

What do you do with the pieces of string!

Counting patterns in a string (Ch. 11)

2007-04-18T11:25:00.000-04:00

Once you are quite familiar with the basic string-handling tools of this chapter (see previous blog entry, and try "Extra Exercises"), you can expand your abilities.

Study carefully the section on Counting Patterns in a Word (p. 182), since it introduces a technique that you will apply in other, related situations. The idea is that, after you search for and find one pattern in a string, before searching again you REDEFINE THE WORD.

You redefine it so that the new word begins somewhere after the position where the first pattern started. For example, if the word was "mississippi" and the pattern was "iss," we would want the word to be redefined as "issippi." How do we do that? The new word will begin somewhere after position 2, where we found the first "iss," using index (word, pattern). But you don't want it to begin exactly AT position 2. You want it to begin at position 2 plus the length of the pattern, in our example the length of "iss." In otyher words, the redefined word begins at

word (index(word, pattern)) + length(pattern)

and it includes the remaining part of the word, namely,

..*)

Putting it all together we redefine the word as follows:

word := word (index(word, pattern) + length(pattern) .. *)

It's easier to understand if you follow the textbook and use a variable pos for the position of the pattern - in our example, iss - and a variable size for the length of the pattern. Your code looks much simpler if you use two variable like these:

pos : int := index (word, pattern)
size : int := length (pattern)

Thus the long, confusing line to redefine the word is much easier to understand when it's simplified to

word := word (pos + size ..*)

Turing, Ch. 10 and 11

2007-04-14T11:49:00.000-04:00

Chapter 10

how to get input from a text file (rather than from the keyboard) using Run With Args on the menu bar
how to output to a text file (rather than to the screen)
how to use the end-of-file (eof) marker when getting input from a file
how to get an entire line of input at once (rather than one word at a time)

Don't spend too much time on Chapter 10. Try the programs in the textbook, learn how to use files, then move on to Chapter 11. There will NOT be a test on Chapter 10. You need to know it for later chapters.

Chapter 11 (Handling Strings) gets quite interesting. There will be a couple of small sections that require you to concentrate, but if you get the basic tools down at the beginning, it will not be a problem.

finding the length of a string with length()
joining (catenating) strings with the + operator
selecting part of a string, e.g. word (4..6)
searching for a pattern in a string e.g. index ("dandelion", "lion")

Week of March 26 - Tests on Turing, Ch. 9

2007-03-22T08:40:00.000-04:00

During next week (March 26 - 30) there will be a programming test on Turing, Ch. 9 (Selection). Since the chapter is simpler than most, this test will be shorter than usual.

Be sure you know how to program
- simple selection (if - then - else - end if)

- multichoice selection (if - then - elsif - then - else - end if)

- the case construct

We will also return to the Norton textbook.

Have a great March Break!

2007-03-09T11:37:00.000-05:00

Test next week on Turing, Ch.8 (PixelGraphics)

2007-03-01T08:52:00.000-05:00

The test at the beginning of next week will, as usual, consist of questions very similar to those at the end of the chapter (but not the most difficult of them)and the "Extra Practice" questions.

STUDY! PRACTISE! Then you will not find the test difficult.

Change of plan -- After the test, we will continue with the next chapter of Turing (not the Nrton textbook).

Nearing the end of Turing, Ch. 8: Pixel Graphics

2007-02-24T15:58:00.000-05:00

Wow! People are doing some amazing things in class! It's more than I expected. I hate to leave this chapter because I love seeing everybody trying things, experimenting and exploring and going beyond what's in the book -- AND HAVING A GOOD TIME!!

But gee, we do have more topics to cover (like IF and text editing and other things), so we'll have a programming test pretty soon and then move back to the Norton textbook first.

The Pickup Folder has answers to the questions at the end of Chapter 8. We'll look at them in class, too, of course.

It's almost time to say goodbye to Chapter 8.

Back to Turing (Ch. 8: Pixel Graphics)

2007-02-09T09:41:00.000-05:00

Despite what I said in the previous blog entry, we did have another test on the Norton textbook, Lesson 28, and it will go into the coming report card.

Now it's back to Turing and the best, most fun part of the course - pixel graphics. This is where you let your creativity loose and make beautiful, colourful, exciting programs.

And it's not even very hard to do (drawdot, drawline, drawbox, etc.).

Norton 27 - Test late next week

2007-01-25T09:34:00.000-05:00

On the last class of next week (Jan.29 - Feb.2) there will be a test on Norton, Lesson 27. That will be the last mark for the coming report card.

We return to the Norton textbook next week (week of Monday, Jan. 22)

2007-01-17T11:54:00.000-05:00

Next week we return to the Norton textbook. Please remember to bring your copy to class.

Test on Ch. 7 of Turing (Character Graphics)

2007-01-12T11:09:00.000-05:00

We will finsh Ch. 7 this week and have a programming test on Ch. 7 next week.

A new flower blooms! - "TIK Source" discussion board and more

2007-01-09T08:54:00.000-05:00

Brian L. has moved the TIK site I mentioned in an earlier posting so that he can offer lots more features, not just blog-type postings but a full discussion board. Check it out.
http://tiksource.ca.tt/

Sorry to add this, but if you tend to be, um, "playful," remember that inappropriate use could cause its decease.

It's 2007!

2007-01-07T09:27:00.000-05:00

Week of Dec. 18

2006-12-20T20:22:00.000-05:00

After the test on Norton 9 and 10, we work on Turing, Computer Graphics.

Most students find the two chapters on graphics to be the most fun part of the course. In this first chapter, you learn some of the basics of graphics and animation. In the next chapter, Pixel Graphics, you go a few steps further and can begin to make some beautiful and fascinating graphics and animations.

Brian's Alternative TIK Blog

2006-12-12T21:33:00.000-05:00

Brian of Period H is keeping an "Alternative" blog for our TIK course at
http://tikjci.blogspot.com/

Hopefully it's all good stuff, interesting and fun and useful and so on.

Brian thinks the design, colours, etc. of my blog are boring, so he's done something different.

One improvement over my blog is that you can leave comments on Brian's blog.

NOTE: You have to talk to Brian to get the username and password, because logging in is required to enter the blog. (Ask Brian about it, not me.)

Week of Dec. 11 - Norton 9 and 10. Test next week.

2006-12-10T09:18:00.000-05:00

At the beginning of this week, we go over the answers to Lesson 9 (it was assigned for homework over the weekend). Afterwards, we continue on to Lesson 10.

Because Lesson 10 is a very short lesson, which we will finish before the end of the week, we will return to the Turing textbook in the last class this week.

TEST NEXT WEEK, LESSONS 9 AND 10
The test will be at the start of next week, so that you have the weekend to study. It will cover lessons 9 and 10 (not Lesson 8).

Week of Dec. 4, Norton textbook

2006-12-04T08:28:00.000-05:00

This week we will finish Ch. 8 (CPUs) and go on to Ch. 9 (Storage).

Lesson 8 worksheet - links to websites now corrected

2006-11-30T06:22:00.000-05:00

The question sheet for Lesson 8 (CPUs) has been updated so that the links to websites now work correctly. The corrected file is in the Pickup Folder.

The corrections in the updated file are:

For more information on the history of Intel chips, including photos, see
http://www.intel.com/museum/online/hist_micro/hof/index.htm
(For a less Intel-centric view of microprocessors, see Great Microprocessors of the Past at http://www.sasktelwebsite.net/jbayko/cpu.html
or the “Microprocessor” article at Wikipedia http://en.wikipedia.org/wiki/Microprocessors )

Norton textbook, week of Nov. 27

2006-11-24T12:10:00.000-05:00

Starting the week of Nov. 27 we return to the Norton textbook.

We also move temporarily to Room 267 while the windows are being replaced in our regular classroom.

Two tests this week (Nov. 20-24)

2006-11-19T22:06:00.000-05:00

This week we will have two tests: (1) a short, 15-20 minute multiple choice test for you to show your understanding and (2) in the final class of the week, a test in which you will have the entire class to show how well you can write programs.

The programming test will have questions very similar to the questions at the end of the chapter or in the "extra practice" exercises you have been working on. No questions on the test will be as difficult as the questions in the textbook we've called "challenging." In other words, if you can solve the standard questions, you can do very well on the test.

The programming test may have as many as seven questions. This may seem like a lot but, in fact, some of them are quite easy so that everyone has a chance to do well.

Week of Nov. 20

2006-11-18T19:06:00.000-05:00

The Pickup Folder has solutions for Questions 1-12. At the beginning of the week in class, we will discuss solutions for Questions 13-16.

The Pickup Folder also has a file entitled "Hints" which points out the easier questions in the textbook and gives hints for the questions that contain difficulties.