AQuadtree (version 1.0.4)

pointsToAQuadtree: Add SpatialPoints to an AQuadtree obtject.

Description

Given an object of class AQuadtree and an object of class SpatialPoints or SpatialPointsDataFrame for the same area, pointsToAQuadtree returns a new object of class AQuadtree aggregating the data from the points to the cells where each point fall.

Usage

pointsToAQuadtree(qt, points)

Value

AQuadtree with the information of the given set of points aggregated at each corresponding cell of the given AQuadtree.

Arguments

qt

object of class "AQuadtree".

points

object of class "SpatialPoints" or "SpatialPointsDataFrame".

Details

The function pointsToAQuadtree returns a new AQuadtree object with the input set of points aggregated to the input AQuadtree object. The function creates a “p.total” attribute to compute the total number of points aggregated to each cell of the input AQuadtree. If points is an object of class SpatialPointsDataFrame, the function summarises numeric attributes in the dataframe using the mean function, and deploys factor attributes creating a new attribute for each label of the factor to calculate the count. The attributes added to the resulting AQuadtree object are prefixed with “p.”.

Examples

data("BarcelonaPop")
Barcelona.QT<-AQuadtree(BarcelonaPop)
BcnWomen75yPop<-BarcelonaPop[BarcelonaPop$sex=='woman' & BarcelonaPop$age>=75, 'age']
Barcelona.extended.QT<-pointsToAQuadtree(Barcelona.QT, BcnWomen75yPop)

if (FALSE) {
## not an AQuadtree object
pointsToAQuadtree(CharlestonCensusTracts, CharlestonPop)

## spatial object not projected
sp.not.projected<-spTransform(CharlestonPop,CRS("+proj=longlat +datum=NAD27"))
is.projected(sp.not.projected)
pointsToAQuadtree(AQuadtree(CharlestonPop), sp.not.projected)

}