multiAR {EWSmethods}

Multivariate Jacobian Index Estimated From Multivariate Autocorrelation Matrix

Description

Estimate the dominant Jacobian eigenvalue of a multivariate time series using autocorrelated stochastic differential equations

Usage

multiAR(data, scale = TRUE, winsize = 50, dt = 1)

Arguments

data

Numeric matrix with time in first column and species abundance in the second

scale

Boolean. Should data be scaled prior to estimating the Jacobian.

winsize

Numeric. Defines the window size of the rolling window as a percentage of the time series length.

dt

Numeric An appropriate time step

Value

A dataframe where the first column is last time index of the window and the second column is the estimated index value. A value <1.0 indicates stability, a value >1.0 indicates instability.

Source

Williamson and Lenton (2015). Detection of bifurcations in noisy coupled systems from multiple time series. Chaos, 25, 036407

Examples

#Load the multivariate simulated
#dataset `simTransComms`

data(simTransComms)

#Subset the second community prior to the transition

pre_simTransComms <- subset(simTransComms$community2,time < inflection_pt)

#Estimate the univariate stability index for the first species in
#the second community

egarJ <- multiAR(data = pre_simTransComms[,2:7],
winsize = 25, dt = 1)