Posts Tagged ‘ ordination ’

Generating sets of permutations

October 21, 2011
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Generating sets of permutations

In previous posts I discussed how to generate a single permutation from a fully-randomised or restricted permutation design using shuffle(). Here I want to briefly mention the shuffleSet() function and illustrate it’s usage. Every time you call shuffle() it has to interpret the … Continue reading →

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permute: a package for generating restricted permutations

October 4, 2011
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permute: a package for generating restricted permutations

Multivariate ordination methods are commonly used in ecology to investigate patterns in species composition in space or time. Constrained ordination methods such as redundancy analysis (RDA) and canonical correspondence analysis (CCA) are effectively just multiple regressions, but we lack the … Continue reading →

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Clarke and Ainsworth’s BIOENV and BVSTEP (and BIO-BIO etc…)

June 30, 2011
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Clarke and Ainsworth’s BIOENV and BVSTEP (and BIO-BIO etc…)

Nonmetric Multidimensional Scaling (NMDS) plot of vegetation sample dissimilarities with best correlating environmental variables (left) and species (right) plotted as vectors (datasets "varespec" and "varechem" from the package ...

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