Theory, Examples & Exercises
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Section: Numerical classification
Run TWINSPAN example1), which shows modified TWINSPAN on traditional Ellenberg's Danube meadow dataset, projected on DCA ordination diagram and compared with original classification into three vegetation types (plus one not-classified releve) made by tabular sorting:
library (twinspanR) library (vegan) data (danube) res <- twinspan (danube$spe, modif = TRUE, clusters = 4) k <- cut (res) dca <- decorana (danube$spe) par (mfrow = c(1,2)) ordiplot (dca, type = 'n', display = 'si', main = 'Modified TWINSPAN') points (dca, col = k) for (i in c(1,2,4)) ordihull (dca, groups = k, show.group = i, col = i, draw = 'polygon', label = TRUE) ordiplot (dca, type = 'n', display = 'si', main = 'Original assignment\n (Ellenberg 1954)') points (dca, col = danube$env$veg.type) for (i in c(1:3)) ordihull (dca, groups = danube$env$veg.type, show.group = unique (danube$env$veg.type)[i], col = i, draw = 'polygon', label = TRUE)
example (twinspan)- this will run the example which comes with the help file of
twinspanfunction (see the section Examples in