COLE@USC-ISIB@sri-unix.UUCP (10/13/83)
From: Randy Cole <COLE@USC-ISIB> I recently spent some time with the TK! Solver program from Software Arts (the people who originally developed Visicalc), and thought I'd pass along my impressions. TK! Solver is a program which solves equations or sets of equations. For example, given a+b=c*d, it can solve for any one of the variables given the other three. It also has an iterative capability, to find things like the zeros of polynomials. It is supposed to be for people like engineers, who want to deal with problems in their own terms and not worry about array indices and loops and other nasty computerish things. The program does what it claims to do. If you can set up the equations that describe what you know it will solve them if you have given it enough information. It does, however, solve them VERRRRRRY SLOOOOOWLY (more about that later). The commands are Visicalc-like (/this and /that), and so is the way commands are typed in and edited and shown at the top of the screen. When a list of available commands is shown, one-letter abbreviations are uses, like "/A S L F", and you have to remember what each is, unlike 123, which spells them out for you. The documentation is very nice. It starts out with a short introduction that leads you through a sample problem. After that there is a tutorial manual and a reference manual. The manual assumes no knowledge of the machine. The program is copy protected. A duplicate disk is supplied. Some of the supporting programs can be copied to a hard disk, but you're still going to have to put the original disk in the drive every time you run the program. There does seem to be one major problem with this program -- FOR THE LIFE OF ME, I CAN'T FIGURE OUT WHAT THE HECK IT IS GOOD FOR. The hard part of solving any engineering problem is figuring out how to describe the problem mathematically. Once you have that done the rest is generally pretty simple. Most people who solve large sets of simultaneous equations probably are using computers to do that already. As for speed, I used TK! Solver to solve the equation x^3 - 6*x^2 = 0 (yes, I know you can figure that one out in your head in about 2 seconds). TK! Solver took 32 seconds to get answer, which was correct. I pulled out my HP calculator and asked it to solve the same equation. It took 17 seconds to get the same answer. TK! Solver must be a beautifully written program. I'm not an AI type, so I couldn't even start to write a program which does what it does, and I have a lot of respect for whoever wrote it. But it sure leaves me asking why they bothered. Randy Cole