Distance between the locations of a movement track
distance.Rd
Calculates the distance between the consecutive locations of a Move or MoveStack object.
Usage
# S4 method for class '.MoveTrackSingle,missing'
distance(x)
# S4 method for class '.MoveTrackStack,missing'
distance(x)
Details
pointDistance
is used to calculate the distances.
Value
Distance in map units.
If the projection of the coordinates is long/lat all values are returned in meters, otherwise in the map units of the projection of the move object. For long/lat distance is calculated on a sphere using the ellipsoid, for other projections the calculation is done on a plane using Pythagoras. Check and set the projection of your Move, MoveStack or MoveBurst object using the proj4string()
function.
If a move
or moveBurst
object is provided, a numeric vector one element shorter than the number of locations is obtained.
If a moveStack
object is provided, a list with one element per individual containing a numeric vector one element shorter than the number of locations is obtained
Examples
## distance from a Move object
data(leroy)
head(distance(leroy))
#> [1] 6.382461 5.606722 12.671263 9.651801 11.733921 13.928818
# to add this information to the move object, a "NA" has to be assigened
# e.g. distance is assigned to the first location of a segment
leroy$distance <- c(distance(leroy), NA)
## distance from a MoveStack object
data(fishers)
str(distance(fishers))
#> List of 2
#> $ Leroy : num [1:918] 6.38 5.61 12.67 9.65 11.73 ...
#> $ Ricky.T: num [1:999] 153.35 12.62 7.81 10.23 13.18 ...
# to add this information to the moveStack object, a "NA" has to be assigened
# e.g. distance is assigned to the first location of a segment
fishers$distance <- unlist(lapply(distance(fishers), c, NA))