Percentage of Like Adjacencies (Aggregation metric)
lsm_c_pladj(landscape)tibble
Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers.
$$PLADJ = (\frac{g_{ij}} {\sum \limits_{k = 1}^{m} g_{ik}}) * 100$$ where \(g_{ii}\) is the number of adjacencies between cells of class i and \(g_{ik}\) is the number of adjacencies between cells of class i and k.
PLADJ is an 'Aggregation metric'. It calculates the frequency how often patches of different classes i (focal class) and k are next to each other, and following is a measure of class aggregation. The adjacencies are counted using the double-count method.
Percent
0 <= PLADJ <= 100
Equals PLADJ = 0 if class i is maximal disaggregated, i.e. every cell is a different patch. Equals PLADJ = 100 when the only one patch is present.
McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: https://www.umass.edu/landeco/.