symmetry_index: Dive/bottom symmetry index

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

Description

Based on the moment where animal reaches the dive maximum depth.

Usage

symmetry_index(x = ind(), type = c("_", "!_/"), time_col = 1,
  depth_col = 2)

Arguments

x	input data, a ses object.
type	Should the index be computed on the bottom phase only (type = "_") or on the complete dive profile (type = "!_/")
time_col	Character or numeric giving the column of the TDR table that stores the timestamps.
depth_col	Character or numeric giving the column of the TDR table that stores the depth sequence

Details

The index ranges from 0 (skewed to the left) to 1 (skewed to the right).

References

Halsey, L.G., Bost, C.-A., Handrich, Y. (2007) A thorough and quantified method for classifying seabird diving behaviour. Polar Biology, 30, 991-1004.

Examples

data(exses)
exses$stat$btt.sym <- symmetry_index(exses)
exses$stat$dv.sym <- symmetry_index(exses, type = "!_/")

plot(exses$stat[ , c("time", "btt.sym", "dv.sym")])

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