cholera (version 0.5.1)

euclideanDistance: Compute the Euclidean distance between cases and/or pumps.

Description

Compute the Euclidean distance between cases and/or pumps.

Usage

euclideanDistance(origin, destination = NULL, type = "case-pump",
  observed = 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.

vestry

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

unit

Character. Unit of distance: "meter", "yard" or "native". "native" returns the map's native scale. 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 data frame.

Examples

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

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

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

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

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