rspectrum: r-spectrum
In spatialwarnings: Spatial Early Warning Signals of Ecosystem Degradation

Description Usage Arguments Details Value See Also Examples

View source: R/RcppExports.R

Compute the r-spectrum of a matrix

1	rspectrum(mat)

mat

A matrix with logical or numeric values

This functions returns a data.frame with NAs in the rspec column if the input matrix has zero variance. Note that if the matrix is not square, then only the largest square matrix fitting in the upper right corner is used.

A data.frame with two columns: dist, the wave number and rspec, the normalized value of the r-spectrum

spectral_spews, indicator_sdr

# Spectrum of white noise
rmat <- matrix(runif(100*100) > .5, ncol = 100)
spec <- rspectrum(rmat) 
plot(spec, type = "l")

# Add some spatial correlation and compare the two spectra
rmat.cor <- rmat
for (i in seq(1, nrow(rmat)-1)) { 
  for (j in seq(1, nrow(rmat)-1)) { 
    rmat.cor[i,j] <- mean(rmat[(i-1):(i+1), (j-1):(j+1)])
  }
}
spec.cor <- rspectrum(rmat.cor)
plot(spec.cor, type = "n")
lines(spec, col = "black")
lines(spec.cor, col = "blue")