earlywarnings (version 1.0.38)

movpotential_ews: Description: Moving Average Potential

Description

movpotential_ews reconstructs a potential derived from data along a gradient of a given parameter the movpotential_ews calculates the potential for values that correspond to a particular parameter. see ref below

Usage

movpotential_ews(X, param = NULL, bw = -1,
    detection.threshold = 0.002, std = 1, grid.size = 50,
    plot.cutoff = 0.5)

Arguments

X

a vector of the X observations of the state variable of interest

param

parameter values corresponding to the observations in X

bw

Bandwidth for smoothing kernels. Automatically determined by default.

detection.threshold

Threshold for local minima to be discarded

std

std

grid.size

number of evaluation points; number of steps between min and max potential; also used as kernel window size

plot.cutoff

cuttoff for potential minima and maxima in visualization

Returns:

Value

• A list with the following elements:
• pars
  values of the covariate parameter as matrix
• xis
  values of the x as matrix
• pots
  smoothed potentials
• mins
  minima in the densities (-potentials; neglecting local optima)
• maxs
  maxima in densities (-potentials; neglecting local optima)
• plot
  an object that displays the potential estimated in 2D

References

Hirota, M., Holmgren, M., van Nes, E.H. & Scheffer, M. (2011). Global resilience of tropical forest and savanna to critical transitions. Science, 334, 232-235.

See Also

generic_ews; ddjnonparam_ews; bdstest_ews; sensitivity_ews;surrogates_ews; ch_ews; livpotential_ews

Examples

X = c(rnorm(1000, mean = 0), rnorm(1000, mean = -2), rnorm(1000, mean = 2))
 param = seq(0,5,length=3000)
 res <- movpotential_ews(X, param)