# speed: Computes the Speed Between Successive Relocations of an... In adehabitat: Analysis of Habitat Selection by Animals

## Description

`speed` measures the speed between successive relocations of animals, using objects of class `traj`.

## Usage

 ```1 2``` ```speed(x, id = levels(x\$id), burst = levels(x\$burst), date = NULL, units = c("seconds", "hours", "days")) ```

## Arguments

 `x` an object of class `traj` `id` a character vector giving the identity of the animals for which the speed is to be computed `burst` a character vector giving the identity of the circuits for which the speed is to be computed (see `traj`) `date` a vector of class `POSIXct` of length 2 (beginning, end) delimiting the period of interest `units` a character string. It determines how the speeds are computed. For example, if the coordinates are given in meters, and if `units = "seconds"`, speeds are returned in meters per second.

## Value

Returns a data frame with the following components:

 `id` the identity of the animal `x` if the speed is computed between the relocation 1 and 2, the x coordinate of the relocation 1. `y` if the speed is computed between the relocation 1 and 2, the y coordinate of the relocation 1. `date` a vector of class `POSIXct`, giving the date of relocation 1. `burst` the identity of the circuit `sp.x` the computed speed of the animal in the x direction `sp.y` the computed speed of the animal in the y direction `speed` the computed speed of the animal on the plane. `dt` the duration between the two relocations (in the units given by the parameter `units`).

## Note

The function `speed` is deprecated. The class `ltraj` computes the speeds automatically (see `ltraj`).

## Author(s)

Clement Calenge [email protected]

`traj`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```## Not run: #### Computes the speed for each wild boar #### monitored at Puechabon data(puechcirc) puechcirc <- ltraj2traj(puechcirc) puechcirc plot(puechcirc) sp <- speed(puechcirc) sp[1:4,] ## End(Not run) ```