cholera (version 0.5.1)

walkingPath: Compute the shortest walking path between cases and/or pumps.

Description

Compute the shortest walking path between cases and/or pumps.

Usage

walkingPath(origin, destination = NULL, type = "case-pump",
  observed = TRUE, weighted = TRUE, vestry = FALSE, unit = "meter",
  time.unit = "second", walking.speed = 5)

Arguments

origin

Numeric or Integer. Numeric ID of case or pump.

destination

Numeric or Integer. Numeric ID(s) of case(s) or pump(s). Exclusion is possible via negative selection (e.g., -7). Default is NULL: this returns closest pump or "anchor" case.

type

Character "case-pump", "cases" or "pumps".

observed

Logical. Use observed or "simulated" expected data.

weighted

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

vestry

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

unit

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

time.unit

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

walking.speed

Numeric. Walking speed in km/hr.

Value

An R list with two elements: a character vector of path nodes and a data frame summary.

See Also

fatalities, vignette("pump.neighborhoods")

Examples

# NOT RUN {
# path from case 1 to nearest pump.
walkingPath(1)

# path from case 1 to pump 6.
walkingPath(1, 6)

# exclude pump 7 from consideration.
walkingPath(1, -7)

# path from case 1 to case 6.
walkingPath(1, 6, type = "cases")

# path from pump 1 to pump 6.
walkingPath(1, 6, type = "pumps")

# path from case 1 to nearest pump.
plot(walkingPath(1))
# }