Thursday 2-21-91  8:08:11pm EST

Intro
HÝnon is a demo program that plots maps according to the specifications described by Michel HÝnon. The plotting algorithm is based on an MS-DOS program (originally written in Pascal) that plots these maps. The source code and an article describing it can be found in BYTE, December 1986 (on page 161).
The source code for the NeXT app was written in Objective C, and uses PostScript operations to draw. Other than the algorithm and a few words about HÝnon maps that appear in the Help window, this program is entirely my work. The original Pascal source code was written by Gordon Hughes, a professor of mathematics at California State University.

How To
To build the application, type make when you're in the directory the tar file has been untar'ed into. Then type make install to put the app into your local Apps directory.
To use the application, put it into an Apps directory (either ~/Apps or /LocalApps). This will be done automatically if you use make install, as described above. When the app is where it should be, doubleclick HÝnon's icon.

About Version 0.9
The previous version, v. 0.8, was uploaded to the archive sites in September 1990. It was written to run under System 1.0, and I assumed that it would run under 2.0. Unfortunately, it seems that I was wrong. While the executable should still work fine under 2.0, the source code won't compile correctly. In version 0.9 this has been fixed.
The source code has been cleaned up for version 0.9. While it may still not be as clean as it should be, it's as clean as I'm going to make it. Code that was previously commented out has been removed, and comments have been added. Some parts have also been modified to take advantage of some System 2.0- specific features; these include use of NXImage instead of Bitmap, use of string tables for internationalization, etc. As a result of this, HÝnon v. 0.9 will neither compile nor run under System 1.0! That shouldn't be a problem; everyone should have System 2.0 by now.
The appearance of the executable hasn't been changed very much. A few boxes have been removed, the text style has been changed a little; nothing much. Almost all of the changes that have been made to HÝnon have been to the source code.

Distribution
Please feel free to share this program with anyone who wants it. If you do, please make sure that all of the files originally in this .tar.Z package are included. Preferably, give them an unmodified copy of the original .tar.Z file (as down- loaded from the archive sites).

ªDisclaimerº (sort of)
Please note that this program is not intended to be an example of good design philosophy. Plots should be saveable both as TIFF and EPS, and compression options for TIFF files should be included. Plot parameters should be loadable and saveable, and the controls in the plotter panel should be more intuitive. That's why this release is version 0.9 and not 1.0!

	Anders Bertelrud
	abertel@vttcf.cc.vt.edu