|Re: NORM's CORRECT! (long)|
Message #2 Posted by Vieira, Luiz C. (Brazil) on 22 July 2003, 12:12 a.m.,
in response to message #1 by Trent Moseley
Hi Trent, folks;
I've been wondering sometime ago about programming and usage. As you may have noticed, I think working calculators should be used. I mentioned this fact in an isolated post where Valentin agreed with me, but also showed me (and others as well) that reasons are for storing an working calculator. O.K., not only convincing but also correct points.
After that I thought about Valentin's teasing challenges and I remembered some people here, me included, tried their (our) own challenges. Most of them, if not all of them, were answered by others. I also copied and saved a post by someone that's not a regular contributor (to be honest, I remember this only post by him) explaining the way he used RPN to solve electrical problems. A very "literate" description, you bet.
I still develop and translate programs from one "calculator" (system) to another, mostly for fun. I do not give up doing this, I go as far as I can to accomplish the task. To be honest, there are about fifteen programs I want (and need) to translate from RPN (HP41) to RPL (HP48) and I cannot find the "large and spare" time to do it. The fact is that the first of these programs uses loops that constantly update registers contents in order to achieve an expected result. The truth is that these loops are custom root-finders, and I did not take the time to "depict" them so I can "see" the original expression and use local RPL resources to find roots. It's teasing and fun to do, also keeps some parts of our brains working and alive, if you understand me. If it is not fun doing, I see no reason to do so. Maybe plenty bux in my pocket...
Well, I use about all of the models I have for my own delightful moments, but as a teacher, I must be close to the students and their own resources. So far, only two of the many students I had brought HP calculators to my classes: one HP32S (I tried the harder I could to trade it, but the owner did not want to :( for "personal reasons") and one HP48G. The HP32S' owner gave up studying and the HP48G's owner gave up using it and bought a CASIO...
What to do? Teaching them how to use their own calculators. I get each available model in the classroom and I figure out the fastest, easiest way to convert from DEGress to RADians, compute trigs (direct and inverses) in DEGrees and RADians mode (I only explain what GRAD stands for, but I do not use it in class), convert from polar to rectangular and vice-versa in each of them. Then I show how to use it all to perform complex arithmetic and apply it to vectors and impedances. I think this helps them finding useful applications to their small, key-filled magic boxes. If they understand how to use them, they will not try to make them give answers everytime their keys are pressed. Instead, when the problem is solved, calculators are good to help with numbers since the correct operations are performed. I do not say stuffs like: "Press this and that keys and you'll find the answer". Instead, I say "How do you compute this value? Use sine of the angle times the amplitude, right? How do you compute sine of this angle in your calculator? How much is it?" Then each one gives the answer, and when there are different answers, I tease them to find where they were wrong. In most cases, they are able to find their own errors and they exchange their calculators with the others till they find their own errors. It's amazing to see some of them going from one desk to another and showing their classmates how did they find their answer. Everyone learns a bit with each other. Too bad they do not find RPN calculators easily... In fact, most of them are worried in learning the subject, and as a teacher I must accept it as good thing because it IS actually what teachers want.
Here, at MoHPC forum (thanks Dave and all of you, guys) is the place I find people to talk about RPN, RPL, stack manipulation, programming and the like. I'd like very much to discuss programming techniques, daily use, etc. I prefer not restricting to this or that fact, instead I'd like to see what others are doing. If what I'm doing is not the best way, let me see another, better way. When I was teaching programming basics, I used to say: "If your program gives the correct results for a given set of parameters, it is already the best program. If you want to reduce its size and enhance it's performance, it's a matter of goals and needs." I also always emphasized the fact that programming and using a language are related subjects, but should never be taught at the same time. Programming is a matter of recognizing a problem, finding its solution and teaching someone else how to do this. A programming language is the tool to teach a programmable machine how to do this in its own way, and it's sometimes not too close to the way you understand it. As I have students that naturally speak Portuguese, their understanding of "printf", "scanf", "if...else", "for" and "while" is not as natural as for English speakers. And most of them do not relate their understanding of English with those "keywords".
Sorry; I'm getting out of focus.
I know some will disagree with me, but I take programming as the best part a computing device may offer. Mostly a portable, continuous memory, resourceful computing device as a calculator can be.
Wow! All of this to express my own wishes to participate in any thread where usage, programming calculators and the like is the main subject. I like to use and program them as much as I like to understand how they work and to repair them. If it's worth accepting me as handy, count on me. Actually, I support.
Edited: 22 July 2003, 12:16 a.m.