addEuclideanPath: Add the path for the Euclidean distance between cases and/or...

In cholera: Amend, Augment and Aid Analysis of John Snow's Cholera Map

Add the path for the Euclidean distance between cases and/or pumps.

Description

Add the path for the Euclidean distance between cases and/or pumps.

Usage

addEuclideanPath(origin, destination = NULL, type = "case-pump",
  observed = TRUE, case.location = "address", vestry = FALSE,
  distance.unit = "meter", time.unit = "second", walking.speed = 5,
  unit.posts = "distance", unit.interval = NULL, alpha.level = 1)

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.
case.location	Character. For observed = FALSE: "address" or "nominal". "address" is the x-y coordinate of a stack's "anchor" case. "nominal" is the x-y coordinate of a bar.
vestry	Logical. TRUE uses the 14 pumps from the Vestry Report. FALSE uses the 13 pumps from the original map.
distance.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.
unit.posts	Character. "distance" for mileposts; "time" for timeposts; NULL for no posts.
unit.interval	Numeric. Sets interval between unit.posts.
alpha.level	Numeric. Alpha level transparency for path: a value in [0, 1].

Value

An R list with 3 data frames: x-y coordinates for the origin and destination, and a summary of results.

Note

Walking time is computed using distanceTime().

cholera documentation built on March 7, 2023, 5:31 p.m.