simulate_track {QuAnTeTrack}R Documentation

Simulate tracks using different models

Description

simulate_track() simulates movement trajectories based on an original set of tracks. Three movement models are available for simulation, each reflecting different levels of constraint in movement patterns. These models can represent biological or environmental constraints, such as movement along coastlines, rivers, or towards resources like water or food.

Usage

simulate_track(data, nsim = NULL, model = NULL)

Arguments

data

A track R object, which is a list consisting of two elements:

  • Trajectories: A list of interpolated trajectories, where each trajectory is a series of midpoints between consecutive footprints.

  • Footprints: A list of data frames containing footprint coordinates, metadata (e.g., image reference, ID), and a marker indicating whether the footprint is actual or inferred.

nsim

The number of simulations to run. Defaults to 1000 if not specified.

model

The type of movement model to use. Options are "Directed", "Constrained", or "Unconstrained". Defaults to "Unconstrained" if not provided.

Details

This function simulates movement trajectories based on the following models:

This model is ideal for simulating movement directed toward a specific resource or constrained by natural barriers, with a relatively fixed direction and minor deviations.

This model is suitable for scenarios where movement is influenced by external constraints but allows for some degree of random exploration.

This model is suitable for simulating exploratory or dispersal behavior in open environments, where movement is random and not influenced by specific constraints.

Note: Simulations cannot be applied to trajectories with fewer than four steps as the standard deviations of angles and step lengths cannot be computed for such short trajectories. Consider using the subset_track() function to filter tracks with four or more steps.

The function utilizes the trajr package for key calculations:

The NISTdegTOradian() function from the NISTunits package is used to convert angles from degrees to radians.

Value

A track simulation R object consisting of a list of simulated trajectories stored as track R objects.

Logo

Logo.png

Author(s)

Humberto G. Ferrón

humberto.ferron@uv.es

Macroevolution and Functional Morphology Research Group (www.macrofun.es)

Cavanilles Institute of Biodiversity and Evolutionary Biology

Calle Catedrático José Beltrán Martínez, nº 2

46980 Paterna - Valencia - Spain

Phone: +34 (9635) 44477

References

Cheung, A., Zhang, S., Stricker, C., & Srinivasan, M. V. (2007). Animal navigation: the difficulty of moving in a straight line. Biological cybernetics, 97, 47-61.

Cheung, A., Zhang, S., Stricker, C., & Srinivasan, M. V. (2008). Animal navigation: general properties of directed walks. Biological cybernetics, 99, 197-217.

See Also

tps_to_track, plot_sim, subset_track, TrajGenerate, TrajStepLengths, TrajAngles, TrajRotate, TrajTranslate, NISTdegTOradian

Examples

# Example 1: Simulate tracks using data from the Paluxy River
# Default model (Unconstrained movement)
simulated_tracks <- simulate_track(PaluxyRiver, nsim = 3)

# Example 2: Simulate tracks using the "Directed" model, representing movement
# toward a resource (e.g., water source)
simulated_tracks_directed <- simulate_track(PaluxyRiver, nsim = 3, model = "Directed")

# Example 3: Simulate tracks using the "Constrained" model, representing movement
# along a geographic feature (e.g., coastline)
simulated_tracks_constrained <- simulate_track(PaluxyRiver, nsim = 3, model = "Constrained")

# Example 4: Simulate tracks using the "Unconstrained" model (random exploratory movement)
simulated_tracks_unconstrained <- simulate_track(PaluxyRiver, nsim = 3, model = "Unconstrained")

# Subsetting trajectories with four or more steps in the MountTom dataset
sbMountTom <- subset_track(MountTom, tracks = c(1, 2, 3, 4, 7, 8, 9, 13, 15, 16, 18))

# Example 5: Simulate tracks using data from Mount Tom
# Default model (Unconstrained movement)
simulated_tracks_mt <- simulate_track(sbMountTom, nsim = 3)

# Example 6: Simulate tracks using the "Directed" model for Mount Tom, representing
# directed movement
simulated_tracks_mt_directed <- simulate_track(sbMountTom, nsim = 3, model = "Directed")

# Example 7: Simulate tracks using the "Constrained" model for Mount Tom, representing
# constrained movement
simulated_tracks_mt_constrained <- simulate_track(sbMountTom, nsim = 3, model = "Constrained")

# Example 8: Simulate tracks using the "Unconstrained" model for Mount Tom, representing
# random exploratory movement
simulated_tracks_mt_unconstrained <- simulate_track(sbMountTom, nsim = 3, model = "Unconstrained")


[Package QuAnTeTrack version 0.1.0 Index]