# lsm_p_para: PARA (patch level) In r-spatialecology/landscapemetrics: Landscape Metrics for Categorical Map Patterns

## Description

Perimeter-Area ratio (Shape metric)

## Usage

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 lsm_p_para(landscape, directions) ## S3 method for class 'RasterLayer' lsm_p_para(landscape, directions = 8) ## S3 method for class 'RasterStack' lsm_p_para(landscape, directions = 8) ## S3 method for class 'RasterBrick' lsm_p_para(landscape, directions = 8) ## S3 method for class 'stars' lsm_p_para(landscape, directions = 8) ## S3 method for class 'list' lsm_p_para(landscape, directions = 8) 

## Arguments

 landscape Raster* Layer, Stack, Brick or a list of rasterLayers. directions The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).

## Details

PARA = \frac{p_{ij}} {a_{ij}}

where p_{ij} is the perimeter in meters and a_{ij} is the area in square meters.

PARA is a 'Shape metric'. It describes the patch complexity in a straightforward way. However, because it is not standarised to a certain shape (e.g. a square), it is not scale independent, meaning that increasing the patch size while not changing the patch form will change the ratio.

None

PARA > 0

#### Behaviour

Increases, without limit, as the shape complexity increases.

tibble

## References

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: http://www.umass.edu/landeco/research/fragstats/fragstats.html

lsm_p_area, lsm_p_perim,
lsm_c_para_mn, lsm_c_para_sd, lsm_c_para_cv,
lsm_l_para_mn, lsm_l_para_sd, lsm_l_para_cv
 1 lsm_p_para(landscape)