Number of locations

Estimate the number of locations for multiple taxa

locations.comp(
  XY,
  method = "fixed_grid",
  nbe_rep = 0,
  protec.areas = NULL,
  Cell_size_locations = 10,
  method_protected_area = "no_more_than_one",
  ID_shape_PA = "WDPA_PID",
  Rel_cell_size = 0.05,
  parallel = FALSE,
  NbeCores = 2,
  show_progress = TRUE
)

Arguments

XY	data.frame, see details
method	string, indicating the method used for estimating the number of locations. Either "fixed_grid" or "sliding scale". See details. By default, it is "fixed_grid"
nbe_rep	numeric , indicate the number of raster with random starting position for estimating the number of locations By default, it is 0 but some minimal translation of the raster are still done
protec.areas	SpatialPolygonsDataFrame, shapefile with protected areas. If provided, this will be taken into account for calculating number of location (see Details and method_protected_area). By default, no shapefile is provided
Cell_size_locations	numeric, value indicating the grid size in kilometers used for estimating the number of location. By default, equal to 10
method_protected_area	string, by default is "no_more_than_one"", which means occurrences within protected areas (if provided) will not be taken into account for estimating the number of locations following the grid system, see Details. By default, it is "no_more_than_one"
ID_shape_PA	string, indicating the field name of protec.areas with ID of the SpatialPolygonsDataFrame of protected areas
Rel_cell_size	numeric, if method_locations="sliding scale", Cell_size_locations is ignored and the resolution is given by the maximum distance separating two occurrences multiplied by Rel_cell_size. By default, it is 0.05
parallel	logical, whether running in parallel. By default, it is FALSE
NbeCores	string integer, register the number of cores for parallel execution. By default, it is 2
show_progress	logical, whether a bar showing progress in computation should be shown. By default, it is TRUE

Value

A list with one list for each species containing [[1]]SpatialPolygonDataframe and [[2]]vector of the number of location.

Details

Input as a dataframe should have the following structure:

It is mandatory to respect field positions, but field names do not matter

[,1]	ddlat	numeric, latitude (in decimal degrees)
[,2]	ddlon	numeric, longitude (in decimal degrees)
[,3]	tax	character or factor, taxa names

References

Gaston & Fuller 2009 The sizes of species'geographic ranges, Journal of Applied Ecology, 49 1-9

Examples

data(dataset.ex)
if (FALSE) {
locations <- locations.comp(dataset.ex)
}

# This would estimate the number of locations for all taxa by overlaying 
# randomly a grid 100 times. For each taxa, the minimum value is kept
if (FALSE) {
locations <- locations.comp(dataset.ex, nbe_rep = 100)
}