mnllCCRW: Maximum likelihood estimation of the CCRW

Description Usage Arguments Details References See Also Examples

Description

Minimize the negative log-likelihood for the CCRW though the EM-algorithm.

Usage

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mnllCCRW(SL, TA, TA_C, missL, notMisLoc, SLmin, tol=5e-5)

Arguments

SL

numeric vector containing the step lengths

TA

numeric vector containing the turning angles

TA_C

circular object containing the turning angles

missL

integer vector containing the number of time step between two steps. If no missing location it will be 1.

notMisLoc

integer vector containing the index of the locations that are not missing

SLmin

one numeric value representing the minimum step length

tol

double: value that indicates the maximum allowed difference between the parameters, default 5e-5

Details

This function uses the function emHMM to minimize the negative log-likelihood. Note that emHMM requires setting starting parameter values. To decrease the chances of having results associated with a local peak in the likelihood, the function mnllCCRW applies the EM-algorithm function emHMM to set of different starting values combinations and choose the overall lowest negative log-likelihood estimate. To explore the effect of starting values, use directly emHMM function.

References

Please refer to Auger-Methe, M., A.E. Derocher, M.J. Plank, E.A. Codling, M.A. Lewis (2015-In Press) Differentiating the Levy walk from a composite correlated random walk. Methods in Ecology and Evolution. Preprint available at http://arxiv.org/abs/1406.4355

See Also

emHMM

Examples

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simPath <- simmCCRW(500,0.9,0.9,0.1,0.01,5,1)
formPath <- movFormat(simPath)
mnllCCRW(formPath$SL, formPath$TA, formPath$TA_C, 
      formPath$missL, formPath$notMisLoc, formPath$SLmin)

MarieAugerMethe/CCRWvsLW documentation built on May 7, 2019, 2:50 p.m.