This implements the label propagation algorithm described in our upcoming paper.

createCatchment(
  supplyShape,
  supplyIdVar = "code",
  supplyVar,
  supplyOutputVars = supplyShape %>% dplyr::groups(),
  demandShape,
  demandIdVar = "code",
  demandVar,
  growthConstant = 1.2,
  bridges = arear::ukconnections,
  outputMap = TRUE
)

Arguments

supplyShape

- a sf object containing a list of the locations of supply points, with a column containing supply capacity, for example NHS hospital sites, with a bed

supplyIdVar

- the variable name of the identifier of the supplier or group of suppliers. For example this could be an NHS trust (multiple sites)

supplyVar

- the column name of the supply parameter. This could be number of beds in a hospital.

supplyOutputVars

- (optional - defaults to grouping) the columns from the input that are to be retained in the output

demandShape

- the sf object with the geographical map of the demand surface. For example the geographical distribution of the population served,

demandIdVar

- the column name of the unique identifier of the areas,

demandVar

- the column name of the demand parameter. This could be the population in each region

growthConstant

- a growth parameter which defines how quickly each label propagates

bridges

- a named list containing extra linkages beyond those inferred by the demandShape topology. These are used to add in bridges

outputMap

- should we export a shapefile or just the mapping file

Value

a dataframe containing the grouping columns, the outputIdVar and the interpolated value of interpolateVar