I found the data we're meant to locate on the Internet pretty quick, but had a merry old time of it (actually "grumpy old time" would be more accurate.)
For any latecomers arriving here and finding themselves faced with either a blank screen or an ugly blob, here is the basic path to follow:
1. The data is all right. You'll find a set I haven't succeeded with on myUnisa (but you know that already), and you'll find two sets on the Internet, one on top of the other. If you find that one, you'll want to know that with some modifications I got the set full of floats to work for me.
Academically the first thing should be to say what the data mean (as far as I can tell), but if you're where I was this morning all you really want to know is "what modifications"? Naturally I can't tell directly, but follow the indirect hint and you'll be all right: Go through pages 193, 194 nice and slowly. Look at what is being talked about in each paragraph nice and closely, and observe closely the format of the data there. That's your model. Now go and look at the jumble of data you have from the Intenet, and modify it to fit the pattern. It'll work. You may not see it at work right away, but it'll work.
If you're unhappy with the data you find, ask, and I'll ensure that there are even more sets of data available on this, the Internet.
2. Now if you work stepwise you could end up cursing me after following step 1, and finding that all you get is either a blank screen or an ugly "blob" in the middle of the screen.
I'm afraid that if that happens to you, you might have to say "Oh well, I've failed the rendering part of the question for the time being; so let me salvage what I can out of the further parts". That may sound like a suggestion that you just give up, but you never know: You might just get lucky. It might turn out to be a rather backhanded kind of tip.
3. OK, so you have either a blob or a blank (but a possibly untrustworthy reassurance that your job is done there), and you've moved deeper into the question, trying to make that blob or blank viewable from different places, and still it's a mess?
A few questions might help:
Have you looked at the code in the Appendix as well?
How sure are you that your "eye" is in the right place? (Consider where the book would say you'd be viewing from).
I can probably come up with more tips, but these should do for now. Too direct is either cheating for you, or spoiling your fun (it feels like a pretty horrible kind of "fun" right now, if you're stuck - and the bad news is this could last for days on end if you're like me - but when it all starts to come together the miserable aspects of fun will make the usual fun even better).
Oh. And hey ho, Phyz. You reckon this is vague enough, but not misleading? It's a bit of a difficult balancing act.
On myUnisa they're saying the keyboard solution is different from the book, but I've not found that.
Found a nice practical explanation of why things behave the way they do when you walk through, there, so probably for the first time ever "go and look at the myUnisa discussion" is a good tip, too.