adehabitatLT (version 0.1)

redisltraj: Rediscretization of a Trajectory With Regular Step Length

Description

This functions rediscretizes one or several trajectories in an object of class ltraj.

Usage

redisltraj(l, u, burst = NULL, samplex0 = FALSE, addbit = FALSE,
           nnew = 5)

Arguments

l

an object of class ltraj

u

the new step length

burst

The burst identity of trajectories to be rediscretized.

samplex0

Whether the first relocation of the trajectory should be sampled

addbit

logical. Whether the line segment linking the last relocation of the rediscretized trajectory and the last relocation of the raw trajectory should be added to the result (can be useful for computation of fractal dimension)

nnew

optionnally, you may specify the maximum ratio between number of relocations of the new trajectory. If not specified, this maximum is equal to 5 times the number of relocations of the raw trajectory.

Value

• An object of class "ltraj"

Details

The rediscretization of trajectory has been advocated by several authors in the literature (Turchin 1998, Bovet & Benhamou 1988). It is also the first step of the computation of the fractal dimension of the path (Sugihara & May 1990).

References

Bovet, P., & Benhamou, S. (1988) Spatial analysis of animal's movements using a correlated random walk model. Journal of Theoretical Biology 131: 419--433. Turchin, P. (1998) Quantitative analysis of movement, Sunderland, MA.

Sugihara, G., & May, R. (1990) Applications of fractals in Ecology. Trends in Ecology and Evolution 5: 79--86.

See Also

ltraj for further information on objects of class ltraj

Examples

data(puechcirc)

puechcirc

## before rediscretization
plot(puechcirc, perani = FALSE)

## after rediscretization
toto <- redisltraj(puechcirc, 100)
plot(toto, perani = FALSE)