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Niche analysis using ECDF and chi-squared

ecdf_theoretical_niche.Rd

Simulate niche suitability from Mahalanobis distance using both chi-squared and empirical CDF transformations, for a given number of predictor variables.

Usage

ecdf_theoretical_niche(
  n,
  n_population = 10000L,
  sample_sizes = seq(20L, 500L, 20L),
  seed = NULL
)

Arguments

n

Integer; number of predictor variables (dimensions).

n_population

Integer; size of simulated environmental population.

sample_sizes

Integer vector of sample sizes to evaluate.

seed

Optional integer seed for reproducibility.

Value

A list with:

  • corplot: ggplot object with correlation vs sample size.

  • sample_data: matrix of simulated sample points.

  • sample_niche: numeric vector of “true” niche suitability.

  • chisq_suits: numeric vector, 1 - pchisq(Mahalanobis).

  • ecdf_suits: numeric vector, 1 - ECDF(Mahalanobis).

  • mahal_dists: numeric vector of Mahalanobis distances.

Author

Luíz Fernando Esser

Examples

# Create ECDF-niche based on personalized options:
n <- ecdf_theoretical_niche(n = 3,
                            n_population = 20000,
                            sample_sizes = seq(50, 1000, 50),
                            seed = 123)