Create a co-occurrence matrix (coma)

Create a co-occurrence matrix (coma)

get_coma(x, neighbourhood = 4, classes = NULL)

Arguments

x	A matrix with categories
neighbourhood	The number of directions in which cell adjacencies are considered as neighbours: 4 (rook's case) or 8 (queen's case). The default is 4.
classes	A vector or a list with the values of selected classes from the x object. It is used to calculate coma only for selected classes.

Value

A co-occurrence matrix

Examples

#library(comat)
data(raster_x, package = "comat")

com = get_coma(raster_x)
com
#>   1 2 3
#> 1 4 1 3
#> 2 1 2 2
#> 3 3 2 6

com2 = get_coma(raster_x, classes = c(1, 3))
com2
#>   1 3
#> 1 4 3
#> 3 3 6

data(raster_x_na, package = "comat")
com3 = get_coma(raster_x_na, classes = c(0:3, NA))
com3
#>      0 1 2 3 <NA>
#> 0    0 0 0 0    0
#> 1    0 2 0 2    1
#> 2    0 0 2 1    2
#> 3    0 2 1 0    3
#> <NA> 0 1 2 3    2