Sibly, R.M., Barker, D., Denham, M., Hone, J. and Pagel, P., 2005. On the regulation of populations of mammals, birds, fish and insects. Science 309: 607-610.
Associated software to investigate population regulation follows.
Introduction
Citing the software
Download software
Instructions for use
Adapting the software to run under R
Credits
The generalized logistic equation is:
pgr = r0[1-(N/K)theta],
where pgr is the population growth rate, N is the population
size, K is the carrying capacity, r0 represents
pgr at N = 0, and theta describes the curvature of the
relationship.
The program is based on software used in a recent large analysis of the GPDD database by Sibly et al. (2005). The program here is separate from the GPDD, however, and will estimate theta for one or more population time series provided by the user.
Sibly, R.M., Barker, D., Denham, M., Hone, J. and Pagel, P., 2005. On the regulation of populations of mammals, birds, fish and insects. Science 309: 607-610. Download (free)
If you have downloaded the script, and have installed S-Plus for Windows, double-click the genlogistic.ssc file on your computer. You can then read the instructions in the script. When the input file is ready, as described in the instructions, choose Run from the S-Plus Script menu.
You may wish to run an analysis of the example genlogistic_in.xls file first, or use this as a template for your own input file. It contains made-up data, just intended to demonstrate the correct format.
We have not attempted this ourselves, but here is useful advice from a user of the script, Simon Chamaillé-Jammes of the Centre d'Etudes Biologiques de Chizé - CNRS. "From my own experience the S-plus functions provided here are fully functional under R. The only changes that have to be made are to the data import/export functions in the section '# Main Program'. Replace guiImportData() and guiExportData() with your prefered way of loading and saving data under R, such as read.delim(), load(), etc. See the R documentation for more information. Note, this does not imply that there is no uncessary code or other ways of re-writing it under R. This advice is provided only for your personal information and cannot be considered a guarantee."
The software was developed as part of a NERC Small Research Grant to Professor Richard Sibly (Principal Investigator) and Professor Mark Pagel (Co-Investigator) at the University of Reading School of Animal and Microbial Sciences.
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