The S-Plus simulation code can be 'sourced' into S-Plus by using the following command:

source('c:/.../S_pathway_code.txt')

This simulation generates movement data and exports the data into text files that can be copied and pasted into WinBUGS document files. Arguments for the simulation function are included as comments in the code, as well as descriptions of the code's structure. The pathways are simulated assuming a temperature-dependent random walk algorithm. Temperatures are sea surface temperatures, represented by a random field (SST). Details on the required SST dataset are provided below. 


SST.txt contains data to be imported into S-Plus that is required to simulate movement pathways such as those presented in the article. S-Plus (Insightful Corp.) is a comprehensive statsitical software package with an object-oriented command language suitable for simulation. The software and license must be purchased from Insightful Corp. We used S-Plus 6.0 for Windows, however, our code should work on older Windows versions (e.g., S-Plus 2000, 4.5, 3.3), however, we have not tested for such backwards compatibility. Our pathway simulation code may also work in R, an open-source statistical software package related to S-Plus. R is freely available on the internet (http://www.r-project.org/).

Instructions for importing the SST data into S-Plus are provided here.

The following S-plus command will import the data and convert it into a matrix with appropriate dimensions:

SST<-matrix(scan("c:/.../SST.txt",sep="/t"),100,100,byrow=T)

Other random fields can be generated if you have the S+SpatialStats module (Insightful Corp.), using the rfism() function. For example,

SSTa<-matrix(rfism(expand.grid(x=seq(1,100),y=seq(1,100)),covfun=spher.cov,range=20),100,100)

For further detials on the use of rfsim(), see Kaluzny et al. (1998).

Literature cited

Kaluzny, S.P., S.C. Vega, T.P. Cardoso, & A.A. Shelly. 1998. S+SpatialStats: User's manual for windows and unix. Springer-Verlag, New York.