niche.runif

Uniform sampling from an elliptical niche region.

Implementation of a probabilistic method to calculate 'nicheROVER' (_niche_ _r_egion and niche _over_lap) metrics using multidimensional niche indicator data (e.g., stable isotopes, environmental variables, etc.). The niche region is defined as the joint probability density function of the multidimensional niche indicators at a user-defined probability alpha (e.g., 95%). Uncertainty is accounted for in a Bayesian framework, and the method can be extended to three or more indicator dimensions. It provides directional estimates of niche overlap, accounts for species-specific distributions in multivariate niche space, and produces unique and consistent bivariate projections of the multivariate niche region. The article by Swanson et al. (2015) <doi:10.1890/14-0235.1> provides a detailed description of the methodology. See the package vignette for a worked example using fish stable isotope data.

Martin Lysy

nicheROVER

Niche Region and Niche Overlap Metrics for Multidimensional
Ecological Niches

Ashley D. Stasko

Heidi K. Swanson

niche.runif function

<dl><dt>n</dt>
<dd>Number of random draws.</dd>
<dt>mu</dt>
<dd>Mean vector.</dd>
<dt>Sigma</dt>
<dd>Variance matrix.</dd>
<dt>alpha</dt>
<dd>Probabilistic niche size</dd></dl>

Arguments

Uniform sampling from an elliptical niche region. — niche.runif

<dl>

<dt>n</dt>
<dd>Number of random draws.</dd>


<dt>mu</dt>
<dd>Mean vector.</dd>


<dt>Sigma</dt>
<dd>Variance matrix.</dd>


<dt>alpha</dt>
<dd>Probabilistic niche size</dd>

</dl>

niche.runif: Uniform sampling from an elliptical niche region.

Description

Usage

Value

Arguments

See Also

Examples