IMPGRAPH v0.1 ************* This is a very simple TI-83 BASIC program designed to graph functions which the calculator would not be able to graph "normally," such as implicitly-defined functions. It does this by testing every X and Y value in the current viewing window to see if it satisfies your implicitly-defined equation and graphing all appropriate points as a stat plot function. _____ Usage Launch prgmIMPGRAPH from your calculator's "PRGM -> EXEC" menu, and enter an equation you would like graphed. For example: X^2+XY+Y^2=27 The calculator will begin searching for points which satisfy the equation. While it searches for points, it will display whatever point it is currently testing, so that you can get at least a vague idea of its progress. Once it has finished testing every point in your current viewing window, it will display the "finished" graph. ___________ Limitations So far, IMPGRAPH only operates on the current viewing window - you'll probably want to calcuate an appropriate window beforehand so that you can get all the important points, but not have to sit and wait for it to finish all day! From what I've seen IMPGRAPH generally only shows a few "key points" on the graph, and due to the way it's programmed (horribly), it probably won't put them in the proper order to form a single continuous line - you just have to imply that stuff for now until I can make it work better, or even better, force someone else to do all the work for me. Muahaha. IMPGRAPH is extremely slow... _____ To-Do Get IMPGRAPH to plot functions as a nice, continous line, in as much detail as possible. This will probably mean considerable re-writes and hours of work - in other words, lots more than the 30 minutes or so I put into actually coding anything - and probably will be excruciatingly slow until it's rewritten in assembler language (see below). Convert IMPGRAPH to assembly so it can run at an actually tolerable rate. Because of the type of calculations IMPGRAPH performs, it's almost impossible to run it at a reasonable speed in BASIC. If anyone can get that BASIC -> assembler converter to work, please let me know... _____ Notes IMPGRAPH was designed and tested on my personal TI-83 Plus graphing calculator; it should work on any compatible model, such as the TI-84 Plus and TI-84 Plus Silver Edition. Please, do yourself a favor and don't get a cheap piece of junk like I did, get one that can actually run this program at a reasonable speed... (plus it's better for playing Tetris during class!) And remember, don't trust IMPGRAPH to screw up an assignment that you can make a mess of perfectly well on your own. In other words, if you don't know how to do the math by hand, you really shouldn't trust IMPGRAPH to do it for you. In fact, you probably shouldn't trust IMPGRAPH anyway. _______ License Do whatever the hell you want with this program, I really don't care. If you have any really good ideas - or even better, any really good code - it would be nice if you sent me a copy, but until I can figure out how to hold someone at gunpoint over the Internet I'm probably not going to force you ;-) _______ Contact Questions, comments, death threats, etc. go to .