R/intersect_points.R
intersect_points.Rd
This function allows the user to sample environmental/contextual layers at
arbitrary locations. It complements
the occurrences
function, which allows values of the same set
of layers to be downloaded at species occurrence locations.
NOTE: Requests are currently processed in a *single queue* on the ALA
servers. Processing times may be slow if there are many requests in the
queue. Note also that the actual processing of batch requests is inherently
slow: a large number of points may take quite some time. Be warned.
intersect_points( pnts, layers, SPdata.frame = FALSE, use_layer_names = TRUE, verbose = ala_config()$verbose )
pnts | numeric: vector of latitude/longitude pairs, or a 2 column data.frame or matrix of lat, lons. NOTE: the number of locations must be less than 100000 |
---|---|
layers | string vector: ids of layers to be intersected. The list of
possible layers is available from |
SPdata.frame | logical: should the output should be returned as a SpatialPointsDataFrame of the sp package or simply as a data.frame? |
use_layer_names | logical: if TRUE, layer names will be used as column names in the returned data frame (e.g. "radiationLowestPeriodBio22"). Otherwise, layer id value will be used for column names (e.g. "el871") |
verbose | logical: show additional progress information?
[default is set by |
A SpatialPointsDataFrame containing the intersecting data information. Missing data or incorrectly identified layer id values will result in NA data
The associated ALA web service: https://api.ala.org.au/#ws84
Descriptions of the spatial layers: https://spatial.ala.org.au/ws/layers/index/
if (FALSE) { ## single point with multiple layers layers <- c("cl22", "cl23", "el773") pnts <- c(-23.1, 149.1) intersect_points(pnts, layers) ## equivalent direct web service call: ## https://spatial.ala.org.au/ws/intersect/cl22,cl23,el773/-23.1/149.1 ## multiple points as a grid sampling multiple layers layers <- c("cl22", "cl23", "el773") pnts <- data.frame(expand.grid(lat=seq(-29, -19, by=2), lon=seq(130, 140, by=2))) intersect_points(pnts, layers) }