FEARLUS
The Ghost in the Model
From here you can download the software used in the paper presented at the First conference of the European Social Simulation Association, and submitted to the Journal of Artificial Societies and Social Simulation. A local version of the conference paper is available if you cannot access it through the ESSA-1 website.
In the paper, we analyse a problem we had in FEARLUS with floating point arithmetic, finding that converting to interval arithmetic allows us to detect and warn when there is an issue instead of continuing on regardless into a situation in which the model gets into an invalid state. We also show that making some simple modifications to the Artificial Stock Market changes the output. Interval arithmetic has since proved less effective at dealing with the problems in the ASM than it did in FEARLUS.
The software is released under the GNU General Public Licence. Clicking any of the source download links will be taken as an assertion that you agree to abide by the terms of this licence.
The software is designed to work on a Sun Solaris platform, and should, but may not work on other Unix platforms. Versions for Intel Cygwin are provided where available. Swarm version 2.1.1 is used for FEARLUS on a PC, whilst the testing version dated 2001-12-18 has been used on a Solaris platform for FEARLUS and ASM-2.2.1. ASM-2.4 has been compiled successfully on an XP PC running Swarm 2.2 prerelease 10.
| Package | Description | Sun Solaris | Intel Cygwin | Parameters |
|---|---|---|---|---|
| FEARLUS 0-7 | A version of FEARLUS model 0-6-4 that uses interval arithmetic instead of floating point. | download | download | download |
| FEARLUS 0-6-2 | The version of the FEARLUS model that creates ghost agents due to floating point errors for certain parameters that are not exactly representable in double precision floating point arithmetic. | download | Use the Sun version. | |
| ASM 2.2.1-fp | Three versions of the Artificial Stock Market (version 2.2.1) converted for use in the conference paper. | download | Does not work on Cygwin. | Included in source tarball. |
| ASM 2.2.1-i | The Artificial Stock Market (version 2.2.1) converted for use with interval arithmetic. | download | Does not work on Cygwin. | download |
| ASM 2.4-fp | Three versions of the Artificial Stock Market (version 2.4) converted for use in the JASSS paper. | Use the Cygwin version (with an appropriate version of Swarm) | download | Included in source tarball. |
| lu1lu2sequence.c | A short program to implement a check of sequences of Land Uses applied by a particular kind of agent as discussed in the papers. | download | Use the Sun version. | Not applicable |
We'd appreciate it if you would also be prepared to fill out the form below, letting us know of your interest in these packages, though you are not obliged to do so. It does help to justify this aspect of our work, however. We will not pass the information on to anyone else.