stepdist: Step-Across Distance

In labdsv: Ordination and Multivariate Analysis for Ecology

Step-Across Distance

Description

Solves for the shortest-path step-across distance for a given distance matrix

Usage

stepdist(dis,alpha)

Arguments

dis	a distance or dissimilarity object of class ‘dist’
alpha	a threshold distance to establish the step-across

Details

The function takes the dist object and converts all values >= alpha to 9999.9 and then solves for new distances by calculating the transitive closure of the triangle inequality.

Value

an object of class ‘dist’

Note

The ‘dsvdis’ function includes a step-across function in the initial calculation of a distance or dissimilarity matrix. This function simply allows the conversion to take place at a later time, or on distance metrics that ‘dsvdis’ doesn't support.

Author(s)

David W. Roberts [e-mail]

Examples

data(bryceveg)
dis.bc <- dsvdis(bryceveg,'bray')
dis.bcx <- stepdist(dis.bc,1.00)
disana(dis.bcx)

labdsv documentation built on April 10, 2023, 5:08 p.m.