prey_catch_attempts: Identify Prey Catch attempts

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

Description

Method based on Viviant et al. (2010) (see references) which was originally implemented on a jaw accelerometer.

Usage

prey_catch_attempts(x, fs = 16, fc = 2.64, w = 1.5, grp = NULL,
  n_days = NULL)

Arguments

x	3 axes acceleration table with time in the first column and acceleration axes in the following columns. Variables must be entitled "time" for time, "ax", "ay", and "az" for x, y and z accelerometer axes.
fs	sampling frequency of the input data (Hz).
fc	Cut-off frequency for the butterworth high pass filter (Hz). Frequency above which signals across x, y and z accelerometer axes are retained.
w	window width in seconds to use when applying rolling standard deviation.
grp	A vector (with same number of observation than x) which provides a group identifier for observations to be treated by rolling standard deviation separately. For example a dive number or a brokenstick segment number. Leave as NULL to process all data as a single block.
n_days	time period (in days) over which kmeans clustering of negative and positive prey catch attempt behaviours should be performed. Leave as NULL to have no time grouping in kmeans generation.

Value

returns a logical vector of prey catch attempts at 1 Hz frequency. Value is TRUE if the record belong to prey catch attempt FALSE otherwise.

Author(s)

Yves Le Bras, Samantha Cox

References

Viviant, M., Trites, A. W., Rosen, D. A. S., Monestiez, P. and Guinet, C. #(2010). Prey capture attempts can be detected in Steller sea lions and other marine predators using accelerometers. Polar Biol 33, 713–719.

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