intersect_points {ALA4R}R Documentation

Intersect environmental or contextual layers at a given a set of points (coordinates)


Intersect environmental or contextual layers at a given a set of points (coordinates)


intersect_points(pnts, layers, SPdata.frame = FALSE, use_layer_names = TRUE,
  verbose = ala_config()$verbose)



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.


string vector: ids of layers to be intersected. The list of possible layers is available from ala_fields("layers"). Names can be passed as full layer names (e.g. "Radiation - lowest period (Bio22)") rather than id ("el871"). Note: if more than one location has been provided in pnts, the number of layers must be less than 700.


logical: should the output should be returned as a SpatialPointsDataFrame of the sp package or simply as a data.frame?


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")


logical: show additional progress information? [default is set by ala_config]


A SpatialPointsDataFrame containing the intersecting data information. Missing data or incorrectly identified layer id values will result in NA data


Atlas of Living Australia


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: batch requests (multiple points) 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.

See Also



#single point with multiple layers
layers = c('cl22','cl23','el773')
pnts = c(-23.1,149.1)
# equivalent direct web service call:,cl23,el773/-23.1/149.1
## Not run: 
## multiple points as a grid sampling multiple layers
## not run here because it's pretty slow
layers = c('cl22','cl23','el773')
pnts = data.frame(expand.grid(lat=seq(-29,-19,2.0),lon=seq(130.0,140.0,2.0)))

## End(Not run)

[Package ALA4R version 1.01 Index]