get_resdist: Get a matrix of resistance distances for resist_gd

In wingen: Continuous Mapping of Genetic Diversity

Get a matrix of resistance distances for resist_gd

Description

Create a distance matrix based on coordinates and a connectivity layer. The output is a distance matrix where rows represent cells on the landscape and columns represent individual locations on the landscape. Each value is the resistance distance between each sample and each cell calculated using the gdistance package. This matrix is used by resist_gd. If coords_only = TRUE, the result is a distance matrix for the sample coordinates only.

Usage

get_resdist(
  coords,
  lyr,
  fact = 0,
  transitionFunction = mean,
  directions = 8,
  geoCorrection = TRUE,
  coords_only = FALSE
)

Arguments

coords	coordinates of samples as sf points, a two-column matrix, or a data.frame representing x and y coordinates (see Details for important information about projections)
lyr	conductivity layer (higher values should mean greater conductivity) for generating distances. Can be either a SpatRaster or RasterLayer.
fact	aggregation factor to apply to lyr (defaults to 0; note: increasing this value reduces computational time)
transitionFunction	function to calculate transition values from grid values (defaults to mean)
directions	directions in which cells are connected (4, 8, 16, or other), see adjacent (defaults to 8)
geoCorrection	whether to apply correction to account for local distances (defaults to TRUE). Geographic correction is necessary for all objects of the class Transition that are either: (1) based on a grid in a geographic (lonlat) projection and covering a large area; (2) made with directions > 4 (see geoCorrection for more details).
coords_only	whether to return distances only for sample coordinates

Value

a distance matrix used by resist_gd

Examples

load_mini_ex()
distmat <- get_resdist(mini_coords, mini_lyr)

wingen documentation built on May 29, 2024, 9:59 a.m.