Program 'xscanning'
Simulation of multispecies Droop model dynamics.

Author: Tomas A. Revilla
E-mail: t.a.revilla.rimbach | tom_rev
      : @                   | @
      : rug.nl              | yahoo.com


SHORT DESCRIPTION:

This program performs many numerical integrations of ordinary differential equations. The simulation parameters are described in the 'header.h' file, and can be modified there. The different scenarios are controled with the macro BAND, e.g. with 3 species:

BAND 0: each consumes most of the resource for which it has the highest requirement
BAND 1: each consumes most of the resource for which it has the 2nd highest requirement
BAND 2: each consumes most of the resource for which it has the 3rd highest requirement

For each individual run a R-star matrix and a F-hat matrix are computed using RRANGE and FRANGE respectively. Numerical integration is performed and the number of oscillations for each population (and other statistics) are recorded. If this number if bigger than 4 for all populations, the system dynamics is classified as an oscillation. There are additional checks, in order to separate heteroclinic cycles, extinctions, etc... so please have a look at the end of the file 'solve.c'.

The detection is not 100% perfect: in some cases heteroclinic cycles will be taken as extinctions just because there was not enough running time; in other cases we have regular cycles with very low minimum densities that are taken as heteroclic cycles. For this reason there is an option in 'header.h' for printing the time series of all simulations, which you can later plot for visual examination (using GnuPlot). If you chose this option, do not make more than a few hundred of runs, otherwise you can easily fill you hard disk. Please read the file 'header.h'.

SPECIAL LIBRARIES: depends on the GNU Scientific Library

OPERATING SYSTEM: Linux 2.6.18-4-686 i686 GNU/Linux

INSTALLATION:
$ tar -zxvf scanning.tar.gz
$ make

USAGE:
$ xscanning > out.dat

The resulting file contains statistics for each run (e.g. number of oscillations, final densities, etc...), each line starts with an indicator string, e.g. '#04075#' for run number 4075. In addition, you can decide whether or not to include the time series, with or without the quotas. Time series lines start with the indicator string, e.g. '@04075@' for run number 4075. The variables are listed from left to right in the following order:

1st group	Resources
2nd group	Consumers
3rd group	Resource 1 quotas for all consumers
4th group	Resource 2 quotas for all consumers
...

and so on. For example 3 resources and 3 consumers:
R1 R2 R3 N1 N2 N3 Q11 Q12 Q13 Q21 Q22 Q23 Q31 Q32 Q33