divc function

Rao's diversity coefficient also called quadratic entropy

Calculates Rao's diversity coefficient within samples.

divc(df, dis, scale)

Arguments

• df: a data frame with elements as rows, samples as columns, and abundance, presence-absence or frequencies as entries
• dis: an object of class dist containing distances or dissimilarities among elements. If dis is NULL, Gini-Simpson index is performed.
• scale: a logical value indicating whether or not the diversity coefficient should be scaled by its maximal value over all frequency distributions.

Returns

Returns a data frame with samples as rows and the diversity coefficient within samples as columns

References

Rao, C.R. (1982) Diversity and dissimilarity coefficients: a unified approach. Theoretical Population Biology, 21 , 24--43.

Gini, C. (1912) Variabilità e mutabilità. Universite di Cagliari III, Parte II.

Simpson, E.H. (1949) Measurement of diversity. Nature, 163 , 688.

Champely, S. and Chessel, D. (2002) Measuring biological diversity using Euclidean metrics. Environmental and Ecological Statistics, 9 , 167--177.

Author(s)

Sandrine Pavoine pavoine@mnhn.fr

Examples

data(ecomor)
dtaxo <- dist.taxo(ecomor$taxo)
divc(ecomor$habitat, dtaxo)

data(humDNAm)
divc(humDNAm$samples, sqrt(humDNAm$distances))