subsetTrajectories: Trajectory subsetting

In ecotraj: Ecological Trajectory Analysis

Trajectory subsetting

Description

Subsets data structures for trajectory analysis

Usage

subsetTrajectories(
  x,
  site_selection = NULL,
  subtrajectory_selection = NULL,
  survey_selection = NULL
)

Arguments

x	An object of class trajectories (or its children subclasses fd.trajectories or cycles)
site_selection	A character vector indicating the subset of entity (site) trajectories to be selected (if NULL, all sites are included).
subtrajectory_selection	A character vector indicating the subset of cycles or fixed date trajectories to be selected (only used when x is of class fd.trajectories or cycles).
survey_selection	An integer vector indicating the subset of surveys to be included (if NULL, all surveys are included).

Details

When using function subsetTrajectories on cycles or fixed-date trajectories then the parameter site_selection applies to sites (hence allows selecting multiple cycles or fixed-date trajectories). Specific cycles or fixed-date trajectories can be selected using trajectory_selection.

Value

An object (list) of class trajectories (or its children subclasses fd.trajectories or cycles), depending on the input.

See Also

defineTrajectories, trajectoryCyclical

Examples

#Description of entities (sites) and surveys
entities <- c("1","1","1","2","2","2")
surveys <- c(1,2,3,1,2,3)
  
#Raw data table
xy<-matrix(0, nrow=6, ncol=2)
xy[2,2]<-1
xy[3,2]<-2
xy[4:6,1] <- 0.5
xy[4:6,2] <- xy[1:3,2]
xy[6,1]<-1

d <- dist(xy)

# Defines trajectories
x <- defineTrajectories(d, entities, surveys)
x

# Extracts (subset) second trajectory
x_2 <- subsetTrajectories(x, "2")
x_2

ecotraj documentation built on June 8, 2025, 11:24 a.m.