v.maxent.swd - GRASS GIS manual

NAME

v.maxent.swd - Export raster values at given point locations as text file in SWD format for input in Maxent

KEYWORDS

SYNOPSIS

v.maxent.swd

v.maxent.swd --help

v.maxent.swd [-eh] species=string[,string,...] [species_name=string] evp_maps=string[,string,...] [alias_names=string] [evp_cat=string[,string,...]] [alias_cat=string] [nbgp=number] [bgp=string] bgr_output=name species_output=name [nodata=number] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-e: include the original columns in input layers in export to swd file
-h: skip header in csv
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

species=string[,string,...] [required]: vector map(s) of species occurence
species_name=string: Alias-name(s) for species (default: map names).
evp_maps=string[,string,...] [required]: Environmental parameter map(s)
alias_names=string: Alias names for environmental parameter(s)
evp_cat=string[,string,...]: Categorial environmental parameter map(s)
alias_cat=string: Alias names for categorial parameter(s)
nbgp=number: Number or percentage of background points; Default: 10000
bgp=string: Vector layer with background / absence points
bgr_output=name [required]: Background SWD file
species_output=name [required]: Species SWD file
nodata=number: nodata value in output files; Default: -9999

DESCRIPTION
NOTES
SEE ALSO
REFERENCES
AUTHOR

DESCRIPTION

v.maxent.swd Produce a set of SWD files as input to MaxEnt 3.3.3k (version 3.4.1 untested, but should work as well), based on a point vector layer(s) of species distribution(s), a point layer with background points and user-defined raster layers. The user can also let the function create the background point file. (respecting region and mask, if set).

The SWD file format is a simple CSV-like file file format as described in Elith et al. 2011. The first three fields provide the species name, x-coordinate and y-coordinate, while subsequent fields contain the values of the user-selected environmental parameters. Note that the coordinates are not used by the MaxEnt program if all environmental data is given in the SWD format file.

The user can provide one or more species point files, which will be combined in one SWD file. The map names of both the species point layers and the environmental parameters can be replaced by alias names, which will be used by MaxEnt.

NOTES

The SWD output files are simple comma delimited text files (.csv) and can therefore be easily read in in for example R and subsequently used in other models / functions.

REFERENCES

Steven J. Phillips, Miroslav Dudík, Robert E. Schapire.A maximum entropy approach to species distribution modeling. In Proceedings of the Twenty-First International Conference on Machine Learning, pages 655-662, 2004.
Steven J. Phillips, Robert P. Anderson, Robert E. Schapire. Maximum entropy modeling of species geographic distributions. Ecological Modelling, 190:231-259, 2006.
Jane Elith, Steven J. Phillips, Trevor Hastie, Miroslav Dudík, Yung En Chee, Colin J. Yates. A statistical explanation of MaxEnt for ecologists. Diversity and Distributions, 17:43-57, 2011.

AUTHOR

Paulo van Breugel, paulo at ecodiv.earth

SOURCE CODE

Available at: v.maxent.swd source code (history)