BiodiversityR (version 2.16-1)

dist.zeroes: Distance Matrix Transformation

Description

Sample units without any species result in "NaN" values in the distance matrix for some of the methods of vegdist (vegan). The function replaces "NA" by "0" if both sample units do not contain any species and "NA" by "1" if only one sample unit does not have any species.

Usage

dist.zeroes(comm, dist)

Value

The function provides a new distance matrix where "NaN" values have been replaced by "0" or "1".

Arguments

comm

Community data frame with sites as rows, species as columns and species abundance as cell values.

dist

Distance matrix as calculated with function vegdist.

Author

Roeland Kindt (World Agroforestry Centre)

Details

This functions changes a distance matrix by replacing "NaN" values by "0" if both sample units do not contain any species and by "1" if only one sample unit does not contain any species.

Please note that there is a valid reason (deliberate removal of zero abundance values from calculations) that the original distance matrix contains "NaN", so you may not wish to do this transformation and remove sample units with zero abundances from further analysis.

References

Kindt, R. & Coe, R. (2005) Tree diversity analysis: A manual and software for common statistical methods for ecological and biodiversity studies.

https://www.worldagroforestry.org/output/tree-diversity-analysis

Examples

library(vegan)
matrix <- array(0, dim=c(5,3))
matrix[4,] <- c(1, 2, 3)
matrix[5,] <- c(1, 0, 0)
dist1 <- vegdist(matrix, method="kulc")
dist1
dist2 <- dist.zeroes(matrix, dist1)
dist2