landscape.windows.regular: Landscape windows: regular method

In tleboucher/landscape.windows: Landscape windows functions

Description

This function creates landscape windows into an area defined by a shapefile (shape format) using the 'regular method'. Latitudinal transects aligned every n kilometers are used to place the center of each windows. Windows are aligned along these transects at n kilometers distances between their centers. With default values, to be validated, a window must contain at least 25 sites distributed over at least 80 percents of the window<e2><80><99>s area (at least 1 site in 8 cells of a 3 x 3 grid).

Usage

landscape.windows.regular(data, shape.path, proj, distance, scales,
  min.no.sites = 25, area = 80, nrowcol = 3, plot = FALSE)

Arguments

data	Informations about sites (spatial coordinates). 'data' must have 3 columns: site ID, x and y.
shape.path	Absolute path to the shapefile (study area).
proj	Projection system. 'proj' must be expressed in EPSG code or in CRS.
distance	Distance between the center of each window (in kilometers).
scales	Spatial scales to test. 'scales' must contain 3 values: the minimum windows' size, the maximum windows' size and the gap/break between two scales (in kilometers).
min.no.sites	Minimum number of sites in each window (default = 25).
area	Minimum percentage for the sites distributed over the window<e2><80><99>s area to ensure equal sampling effort across categories (default = 80).
nrowcol	Area is calculated with a grid of n rows/cols. 'nrowcol' determines n value (default = 3).
plot	TRUE or FALSE. Creation of a map of the study area with the centers of the validated windows (default = FALSE).

Value

Output data is a list of 3 objects: a table containing all the validated windows, for each scale, with a list of sites present in each window; a SpatialPointsDataFrame containing the data (sites); and a SpatialPolygon of the study area.

tleboucher/landscape.windows documentation built on May 28, 2019, 7:36 a.m.