Ects version 3.3



Here it is at last! Thanks to the efforts of Ram Lokan, Serge Mouracade, Amjad Patel, and Martin Viger, students at McGill University, the first volume of documentation is now available in English. It is available as a PDF file. Since it is very new, it is bound to contain some errors and typos. Please let me know about any you find!

The current version of Ects is version 3.3, of March 1999, with some revisions in 2000. This is the version for which the second volume of documentation, dated March 1999, was written.

Unless there are cries of protest, I have decided to abandon the old DOS executable of Ects. For the new generation of students who seem to know nothing about computing except point-and-click, a DOS executable seemed an exotic and unfathomable object. There is now therefore a Windows version.

This fact should not be taken to imply that I in any way encourage people to use Windows, the mere existence of which I deplore. However, since Windows machines seem to be available almost everywhere, and since it seems foolish to deny people the opportunity to use Ects as widely as possible, there is good reason for a Windows version to exist. However, it is still what I am told is now called a command-line application, which means that you get your results in what looks like an old DOS window. Let this just serve to remind users that there are better things in the world of computing than Windows.

For the Windows version, you can get what you need to run Ects by downloading the zip Ects3_cygwin.zip, and then unzipping it in an empty directory. The files thereby created can also be obtained singly. They are ects3.exe, the main executable, and three dynamic link libraries needed by the executable: cygwin1.dll, cygncurses6.dll, and cygreadline5.dll. These four files should be present in the same directory. Note that the zip file fits readily on to a floppy disk, whereas the uncompressed files do not. If you plan to travel, it is sensible to keep the zip.

If you are a sensible person, and are working under Linux, you should get the executable ects3. Although this is a statically linked executable, it needs to be run with the version of glibc that I used to link it. If the executable of Ects here does not work, then contact me, and another executable can be built with your version of glibc.

The documentation is at present split across two volumes, the old one, dated March 1993, and the new, dated March 1999. Both are needed for a full description of how Ects operates. A few errors in the older volume have been corrected in the reprinting of 1999. The older volume continues to provide most of the information needed to run Ects for ordinary applications. The newer volume contains information on newer and more advanced functionality, of which the most interesting to most users will be the new capabilities for graphics and automatic differentiation.

Both volumes of documentation are available as PDF files. The first volume is vol1.pdf, the second is vol2.pdf. Please note that both volumes are in French.

The documentation refers to files of Ects commands and data. These can be found in tar.gz format in the file demofiles.tar.gz, or in zip format in demofiles.zip.

The plot command relies on two things: First, the program gnuplot should be accessible in a user's path. This is freely available, and can be compiled for at least as many architectures as can Ects. Next, there should be a directory called tmp in the root directory. With Unix systems, especially including Linux, this will be a matter of course, and the directory will have the necessary permission for anyone to write to it. With other operating systems, the directory should be created if it does not exist, and made world writable.

Whereas it is impossible to prevent a program like Ects from hanging if it is given outrageous numerical data that give rise to floating point exceptions and so forth, this should be a rare event if any reasonable care is taken. On the other hand, any program that gives rise to a segmentation fault (or violation) should be sent to me so that the bug that caused it can be fixed. Although such faults are pretty harmless under Unix, they can necessitate rebooting with other, lesser, operating systems.

A few years ago, Christian Raguet set up the site aide to help people work gently into Ects. It may still be useful, although it is no longer maintained, Christian having found non-academic work that keeps him occupied full time.

Just this year (2003), Pierre-Henri Bono has made enormous efforts to publicise Ects, and to make it possible to use it as widely as possible. You can try his site by clicking here. This site may not be available at all times.

URL: http://russell.vcharite.univ-mrs.fr/ects3