Creation of polygon shapes from bounding coordinates and delimitation of
SpatialPoints data to the defined boundaries. This is an internal function used by function
backgroundGrid.
delimit(bounding.coords, grid, names = NULL)A vector or a list of vectors with bounding coordinates in the following form: c(x1, x2, y1, y2).
Also object returned by function boundingCoords.
SpatialPoints object
Character. Names or IDs to be given to each shape. If not specified names of the object passed to bounding.coords will be given. In case this object has no names the background numbers will be used as names.
A list with two components:
polygonsSpatialPolygons of the bounding boxes
xylist(s) of matrix(ces) of the background xy coordinates in columns.
This function is aimed at restricting the study area inside the bounding boxes
of a group of points (presences). The study area can be represented as a SpatialPoints
object of a regular point grid, this grid also represents the background (excluding
presences) from which pseudo-absences can be sampled.
Ideally, this grid is extracted from the raster objects of the variables (centroids)
to be used for modelling, see xyFromCell,
extract and example below. bbs.grid is the background inside
bbs shapes.
Iturbide, M., Bedia, J., Herrera, S., del Hierro, O., Pinto, M., Gutierrez, J.M., 2015. A framework for species distribution modelling with improved pseudo-absence generation. Ecological Modelling. DOI:10.1016/j.ecolmodel.2015.05.018.