Summarize a continuous-time movement model

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Description

This function returns a list of biologically interesting parameters in human readable format, as derived from a continuous-time movement model.

Usage

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## S3 method for class 'ctmm'
summary(object,level=0.95,level.UD=0.95,...)

Arguments

object

A ctmm movement-model object from the output of ctmm.fit.

level

Confidence level for parameter estimates.

level.UD

Confidence level for the Gaussian home-range area.

...

Unused options.

Value

If summary is called with a single ctmm object output from ctmm.fit, then a table is returned with low, maximum likelihood, and high estimates for the following possible parameters:

tau

The autocorrelation timescales.

area

The Gaussian home-range area, where the point estimate has a significance level of level.UD. I.e., the core home range is where the animal is located 50% of the time with level.UD=0.50. This point estimate itself is subject to uncertainty, and is given confidence intervals derived from level.

speed

The Gaussian root-mean-square (RMS) velocity, which is a convenient measure of average speed.

If summary is called on a list of ctmm objects output from ctmm.select, then a table is returned with the model names and AIC differences, where "IID" denotes the uncorrelated bi-variate Gaussian model, "OU" denotes the continuous-position Ornstein-Uhlenbeck model, and "OUF" denotes the continuous-velocity Ornstein-Uhlenbeck-F model.

Note

Confidence intervals on the autocorrelation timescales assume they are sufficiently greater than zero and less than infinity.

In ctmm v0.3.4 the speed estimate was fixed to be the RMS velocity and not 1/√{2} times the RMS velocity.

Author(s)

C. H. Fleming.

See Also

ctmm.fit, ctmm.select.

Examples

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# Load package and data
library(ctmm)
data(buffalo)

# Extract movement data for a single animal
cilla <- buffalo[[1]]

# Find the best OU movement model
# also see help(variogram.fit)
GUESS <- ctmm(tau=60*60*24*10)
FIT <- ctmm.fit(cilla,GUESS)

# Tell us something interpretable
summary(FIT)