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Section: Ordination analysis

CA & DCA (unimodal unconstrained ordination)

R functions

  • cca (library vegan) - if the environmental matrix is not specified, cca function in vegan package calculates unconstrained correspondence analysis1).
  • decorana (library vegan) - this function implements the original DECORANA program, written by Mark Hill in Fortran, into R. For historical reasons2), only four DCA ordination axes are returned, and this is not easy to change.
  • CA (P. Legendre, Numerical Ecology with R, called CA.newr in the 2nd edition) - code can be found here.
Alternatively to library vegan, there is also a package ca with function ca calculating correspondence analysis, with plot, plot3d and summary functions. Package ade4 offers function dudi.coa.
The function decorana is implementing the original Hill's algorithm for DCA introduced by Fortran program DECORANA, which itself can calculate only four ordination axes; CANOCO behaves in the same way.
en/ca_dca_r.txt · Last modified: 2021/03/03 19:52 by David Zelený

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