install.packages ('devtools')

devtools::install_github("zdealveindy/twinspanR")

install.packages ('devtools')

devtools::install_github("zdealveindy/twinspanR")

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)