density_data: Density data
In Hackout2/mapData: Tools to help with mapping outbreak data

Description Usage Arguments Details Value Examples

Function description process a SpatialPointsDataFrame to give numbers of cases at each unique (x,y) location. Weighting by 1/(local population density) gives corrected numbers which can be used to calculate estimated prevalence.

1	density_data(points, weights = NULL)

`points`	SpatialPointsDataFrame containing the line list of patients. Should include: 1) a slot `@coords` with an n x 2 vector giving the x and y coordinates of each case. (More than one case can have the same co-ordinates.) 2) a slot `@bbox` giving the maximum and minimum x and y co-ordinates.
`weights`	If required, the local population density at each (x, y) coordinate.

Process a SpatialPointsDataFrame to give numbers of cases at each unique (x,y) location. Weighting by 1/(local population density) gives corrected numbers which can be used to calculate estimated prevalence.

A data frame containing x and y co-ordinates, and (weighted) counts. For use by other functions including estimate_density.

if(require(sp)){
# simulate a line list of patient locations
my.linelist <- data.frame(	longitude = round(runif(100, 0, 10), 0.01),
								latitude = round(runif(100, 0, 10), 0.01)
							)
#transform patients dataframe into spatialpointsdataframe
pointspatients <- SpatialPointsDataFrame(my.linelist, data=data.frame(id=1:100))

my.density.data <- density_data(pointspatients)
print(head( my.density.data ))
}