Test 2 Review Questions- Spring 2008


	Welcome to CS1315. Click on the python to add comments. Looking for the book? They have it at the Engineer's Bookstore at 748 Marietta St NW. Here is there website: http://www.engrbookstore.com/ - Monica

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Test 2 Review Questions- Spring 2008

Questions?

In reference to the fist question on the review, increasing the threshold would copy less color values from weathermap.jpg to the Colbert.jpg in place of the pixels with color values designated in BGcolor?
David Phillips

Is this a question? Thanks! Brittany Duncan

Will the layout of this test be similar to Test #1?
Here is the layout for Test 2 as of Wednesday morning. (This may change, as we are still discussing the fine details):

A question about a function that should by now be familiar to you from your experience with pictures and movies. The code for this function is given containing a bunch of gaps that you have to fill in with either variable names that are consistent with the rest of the function, reserved words that make the function syntactically valid, or function invocations that make the function work correctly. To answer this question, you will need to know how functions like copyPicture, blend, chromakey, posterizeMe, etc. work so that if the question in the test is about one of these, you will be familiar with the function and how it works. Don't attempt to memorize any code, though, because the naming details used will be different. We are interested in your understanding of how to make a partially defined function like one of these work properly.
Three questions that require you to mentally execute a program.
- Two of these ask you to work out what they produce and describe or sketch it. To prepare for these, you need to know the general skeleton of picture manipulation and movie production functions and be able to trace through a program text carefully without getting sidetracked by what you think ought to happen. You need to be familiar with all the basic programming concepts that we have described in class: functions, for loops, if/else conditions, assignment of values to variables, etc. and to be able to apply this knowledge to the understanding of an actual program. There is a good example of this in the review questions.
- The other one asks you to say which lines get executed in which circumstances and how often. For this one, you will need to understand for loops, if statements, and the remainder (%) operator.
A multiple choice series of questions about the fundamentals of movie and sound encoding. To prepare for this, you need to review the introduction to the book chapters on movies and sound and how these media are digitized, how they differ from and are similar to the digitization of pictures, how the physical properties of the medium relate to the subjective dimension of perceived movement, loudness and pitch, etc. and the choices we make when encoding movies and sound (e.g choosing a frame rate or sampling rate, respectively). In the case of sound, we have discussed no programming examples in any detail. The questions will just be about the theory.

Colin Potts

Will there be any extra credit points?

Not planned at the moment. Colin Potts

Two quick questions:
In the notes you said that a double in amplitude is about 3 dB but in the book it says 6.

I don't know what notes you're talking about. Thanks! Brittany Duncan

It's approximately 3dB. I wasn't aware of the error in the book. Another way of thinking about decibels is that a tenfold increase in amplitude corresponds exactly to an extra 10dB (i.e. multiply the physical quantity by ten and you add ten to the perceived loudness.) Colin Potts

Also, in the review, the code on the last page about the orange square: I can't seem to figure out what the x = x + rate does. I'm pretty sure that it is moving the square to the right by a rate of 20 pixels per frame, but I just want to be sure. Thanks!

Correct. Thanks! Brittany Duncan

Since the profs are making different test does that format apply to Monica's class too?

Yes. - Monica

Does this review correspond with Monica's test? Or are there things on the review that won't be covered on her test?

See above. Thanks! Brittany Duncan

in question 4 about the mystery function, why does the else statement (lines 14-15) get executed 11 times?

You are the one who came up with the number 11. However, the answer is because frame 9 is when the square will get to the far right side of the screen. So then you will spend 11 frames bringing it back across. Thanks! Brittany Duncan

Just to clarify this, Do the math!

if (frameNumber * rate + 10) < getWidth(canvas)

Buck Scharfnorth

Monica said the section about sound is not going to be on the test. However, the review says that it will. Should we study the sound chapter for this test?

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Test 2 Review- Spring 2008 last edited on 26 February 2008 at 3:52 pm by ic117.ats.gatech.edu