entrogram {elsa} | R Documentation |
Compute sample (empirical) entrogram from spatial data. The function returns a binned entrogram and an entrogram cloud.
entrogram(x, width, cutoff,...)
x |
a spatial object ( |
width |
the lag size (width of subsequent distance intervals) into which cell pairs are grouped for ELSA estimates. If missing, the cell size (raster resolution) is assigned. |
cutoff |
spatial separation distance up to which cell pairs are included in ELSA estimates; as a default, the length of the diagonal of the box spanning the data is divided by three. |
... |
Additional arguments including |
Entrogram is a variogram-like graph to explore spatial structure in a single variable. An entrogram summarizes the spatial relations in the data, and can be used to understand within what range (distance) the data is spatially autocorrelated.
Entrogram |
an object containing entrogram cloud and the entrogram within each distance interval |
Babak Naimi naimi.b@gmail.com
Naimi, B., Hamm, N. A., Groen, T. A., Skidmore, A. K., Toxopeus, A. G., & Alibakhshi, S. (2019). ELSA: Entropy-based local indicator of spatial association. Spatial statistics, 29, 66-88.
file <- system.file('external/dem_example.grd',package='elsa')
r <- raster(file)
plot(r,main='a continuous raster map')
en <- entrogram(r, width=2000)
plot(en)