ld: Quick Conversion of Objects of Class ltraj from and to Dataframes

Description

The two functions ld and dl are useful to quickly convert objects of class ltraj from and to dataframes.

Usage

ld(ltraj)
dl(x)

Arguments

ltraj

an object of class ltraj

an object of class data.frame, containing at least columns named x,y,date.

Value

ld returns an object of class data.frame. dl returns an object of class ltraj.

Details

The function ld concatenates all bursts in an object of class ltraj, adds two columns named id and burst, and, when it is present, also adds the variables in the infolocs component. The function dl creates an object of class ltraj from a data.frame. If no column named id exists, a random ID is generated. If no column named burst exists, the ID is used as burst. The columns named "dx", "dy", "dist", "dt", "R2n", "abs.angle" and "rel.angle" are recomputed by the function (see ?as.ltraj). Additional columns are used as the infolocs component.

Examples

Run this code

data(puechcirc)
 puechcirc ## class ltraj
 uu <- ld(puechcirc)
 head(uu)
 dl(uu)