corVar {SDMtune}

Print Correlated Variables

Description

Utility that prints the name of correlated variables and the relative correlation coefficient value.

Usage

corVar(
  bg,
  method = "spearman",
  cor_th = NULL,
  order = TRUE,
  remove_diagonal = TRUE
)

Arguments

bg

SWD object with the locations used to compute the correlation between environmental variables.

method

character. The method used to compute the correlation matrix.

cor_th

numeric. If provided it prints only the variables whose correlation coefficient is higher or lower than the given threshold.

order

logical. If TRUE the variable are ordered from the most to the less highly correlated.

remove_diagonal

logical. If TRUE the values in the diagonal are removed.

Value

A data.frame with the variables and their correlation.

Author(s)

Sergio Vignali

Examples

# Acquire environmental variables
files <- list.files(path = file.path(system.file(package = "dismo"), "ex"),
                    pattern = "grd",
                    full.names = TRUE)

predictors <- terra::rast(files)

# Prepare background locations
bg_coords <- terra::spatSample(predictors,
                               size = 10000,
                               method = "random",
                               na.rm = TRUE,
                               xy = TRUE,
                               values = FALSE)

# Create SWD object
bg <- prepareSWD(species = "Virtual species",
                 a = bg_coords,
                 env = predictors,
                 categorical = "biome")

# Get the correlation among all the environmental variables
corVar(bg,
       method = "spearman")

# Get the environmental variables that have a correlation greater or equal to
# the given threshold
corVar(bg,
       method = "pearson",
       cor_th = 0.8)