dive_zone_index: Compute goodness of fit of brokenstick models: Dive Zone...

In SESman/rbl: Biologging tools for diving predators in R

Description

An index of the goodness of fit for brokenstick models. Value of the dive zone index ranges from 0 (perfect fit) to 1. See original article in references.

Usage

dive_zone_index(x, iter = NULL, n = NULL)

Arguments

x	a bsm object as returned by brokenstick or optBrokenstick.
iter	the iteration number for which the DZI is to be computed. If iter = NULL then it is set to last BSM iteration.
n	Optional. The number of points to use when calculating the dive zone limits. if NULL then n is set to the number of record in the dataset used to fit the BSM (when available) or 500 (when not available)

Details

If the original TDR data are not available to the function the DZI of the last BSM iteration will be computed using the maximum residual from the previous iteration.

Value

A dzi object with:

• dzi The dive zone index obtained at each iteration.

• max_res The maximum residuals at each iteration.

• dz_Lbnd Dive zone lower bound.

• dz_Ubnd Dive zone upper bound.

• dz_width The difference between the two previous slots i.e. the vertical width of the dive zone.

• dz_Xval A vector giving the x values corresponding to dz_Lbnd, dz_Ubnd and dz_width.

• no_seg A vector giving the number of BSM segments to which the dz_Xval belong.

• seg_width Vertical width covered by BSM segments.

• seq_length Duration of BSM segments.

• pts.x, pts.y, pts.no Breakpoints information inherited from x.

• data The raw data of input BSM when available.

References

Photopoulou, T., Lovell, P., Fedak, M. A., Thomas, L. and Matthiopoulos, J. (2015). Efficient abstracting of dive profiles using a broken-stick model. Methods Ecol Evol 6, 278-288.

Examples

data(exses)
dv <- tdrply(identity, 1:2, no = 100, obj = exses)[[1]]
bsm <- brokenstick(dv) 
dzi <- dive_zone_index(bsm)

dzi
str(dzi)
plot(dzi)

SESman/rbl documentation built on May 9, 2019, 11:10 a.m.