gdistance (version 1.1-1)

shortestPath: Shortest path

Description

Calculates the shortest path from an origin to a goal.

Usage

shortestPath(transition, origin, goal, ...)

Arguments

transition

TransitionLayer object

origin

SpatialPoints, vector or matrix with coordinates

goal

SpatialPoints, vector or matrix with coordinates

...

Additional argument: output

Value

• Transition object.

Details

As an additional argument output, the desired output object can be specified: either TransitionLayer (default) or SpatialLines. If there is more than one path either (1) transition values in the TransitionLayer get values of 1 / number of paths or (2) the SpatialLines object will contain more than one line.

See Also

costDistance, accCost

Examples

#Create a new raster and set all its values to a random value.
  r <- raster(nrows=18, ncols=36) 
  r <- setValues(r,runif(ncell(r), 0.4, 0.6))

  #Create a Transition object from the raster
  tr <- transition(r,mean,8)
  trC <- geoCorrection(tr, type="c")

  #Create two sets of coordinates
  sP1 <- SpatialPoints(cbind(-105,55))
  sP2 <- SpatialPoints(cbind(105,-55))

  #Calculate the shortest path
  sPath1 <- shortestPath(tr, sP1, sP2)
  sPath2 <- shortestPath(tr, sP1, sP2, output="SpatialLines")
  plot(raster(sPath1))
  lines(sPath2)