spatialwarnings (version 1.2)

indicator_moran: Moran's Index at lag of 1

Description

This functions computes the Moran's spatial correlation index (with lag one). It also computes a null value obtained by randomizing the matrix.

Usage

indicator_moran(input, subsize = 1, nreplicates = 999)

Arguments

input

An matrix or a list of matrix object. It should be a square matrix

subsize

logical. Dimension of the submatrix used to coarse-grain the original matrix (set to 1 for no coarse-graining).

nreplicates

Number of replicates to produce to estimate null distribution of index (default: 999).

Value

A list (or a list of those if input is a list of matrix object) of:

• `value`: Spatial autocorrelation of the matrix

If nreplicates is above 2, then the list has the following additional components :

• `null_mean`: Mean autocorrelation of the null distribution

• `null_sd`: SD of autocorrelation in the null distribution

• `z_score`: Z-score of the observed value in the null distribution

• `pval`: p-value based on the rank of the observed autocorrelation in the null distribution.

References

Dakos, V., van Nes, E. H., Donangelo, R., Fort, H., & Scheffer, M. (2010). Spatial correlation as leading indicator of catastrophic shifts. Theoretical Ecology, 3(3), 163-174.

Legendre, P., & Legendre, L. F. J. (2012). Numerical Ecology. Elsevier Science.

Examples

# NOT RUN {
# }
# NOT RUN {
data(serengeti)

# One matrix
indicator_moran(serengeti[1])

# Several matrices
indicator_moran(serengeti)
# }
# NOT RUN {
# }