cholera (version 0.5.1)

nearestPump: Compute shortest walking distances or paths.

Description

Compute shortest walking distances or paths.

Usage

nearestPump(pump.select = NULL, output = "distance", vestry = FALSE,
  weighted = TRUE, case.set = "observed", unit = "meter",
  multi.core = FALSE, time.unit = "second", walking.speed = 5)

Arguments

pump.select

Numeric. Pump candidates to consider. Default is NULL: all pumps are used. Otherwise, selection by a vector of numeric IDs: 1 to 13 for pumps; 1 to 14 for pumps.vestry. Negative selection allowed.

output

Character. "distance" or "path".

vestry

Logical. TRUE uses the 14 pumps from the Vestry Report. FALSE uses the 13 in the original map.

weighted

Logical. TRUE computes shortest path in terms of road length. FALSE computes shortest path in terms of the number of nodes.

case.set

Character. "observed", "expected", or "snow".

unit

Character. Unit of distance: "meter", "yard" or "native". "native" returns the map's native scale. Meaningful only when "weighted" is TRUE and "output" is "distance". See vignette("roads") for information on unit distances.

multi.core

Logical or Numeric. TRUE uses parallel::detectCores(). FALSE uses one, single core. You can also specify the number logical cores. On Windows, only multi.core = FALSE is available.

time.unit

Character. "hour", "minute", or "second".

walking.speed

Numeric. Walking speed in km/hr.

Value

An R data frame or list of 'igraph' paths.