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Downloading Programs used in the book
The text of the book can be read and understood without these programs, but if you have a computer and can run them, then you can explore a lot more about gravity than the book can present. And if you are inclined to do or learn something about computer programming, then you can look at the program files themselves and even modify them. The software is provided to you in an environment called Triana, which is an open-source software package created at the University of Cardiff (UK). Triana provides an intuitive way to assemble programs from components that it provides. So, for example, to simulate a binary system, you just drag the binary-system program from the "toolbox" into the main Triana screen, then drag the display tool (which will show you a graph of the orbits generated by the binary program), and press "go" to see the result. Triana has an extensive system of help files to guide you in its use. To run Triana you need the Java Runtime System for your computer. You can download this for free from the links provided on this page. All the programs in the book are provided in this special version of Triana, and they all allow you to change some starting values so that you can run the programs over and over to experiment with a variety of situations. All the programs also come with HTML-based help files that describe how to use the programs and how to change parameter values. They even contain the text of the programs, if you want to study them. You can look at the help files for individual files here. Triana also provides a sophisticated programming environment. It allows you, from within Triana, to look at the text of the programs, to edit the programs, and even to edit the help files! To edit the programs or create new ones, you will have to have the full Java Development System, which contains the Java compiler. This can be downloaded from the links provided on this page. Once you tell Triana where you have installed this, you don't have to worry about the details of how to operate the compiler. Triana does it all, shows you any errors, and installs the finished program in a toolbox. Indeed, Triana has a wizard that helps you create a new program from scratch, providing you with all the code you need except of course the specific code for whatever job you want your new program to do. Download Triana for Gravity From the Ground Up Download Java: For running Triana you just need the Java runtime system, obtainable here. Chances are you already have it installed on your PC. For changing the programs or creating new ones, you need the full Java system. For more information about Triana, and downloading the full version, which contains many more tools than the one provided here, go to the Cardiff Triana website. |