earlywarnings (version 1.0.32)

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, sdwindow = NULL, bw = -1,
    minparam = NULL, maxparam = NULL, npoints = 50,
    thres = 0.002, std = 1, grid.size = 200, cutoff = 0.5)

Arguments

X

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

param

parameter values that correspond to the X observations

sdwindow

window for smoothing kernels (over the param axis)

bw

bandwidth used for smoothing kernels

minparam

minimum value of parameter on which to estimate potential

maxparam

maximum value of parameter on which to estimate potential

npoints

number of potentials

thres

threshold for local minima to be discarded

std

std

grid.size

number of evaluation points

cutoff

the cuttof value to estimate minima and maxima in the potential

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, npoints = 100, thres = 0.003)