costatis function

STATIS and Co-Inertia : Analysis of a series of paired ecological tables

Analysis of a series of pairs of ecological tables. This function uses Partial Triadic Analysis (pta ) and coinertia

to do the computations.

costatis(KTX, KTY, scannf = TRUE)

Arguments

• KTX: an objet of class ktab
• KTY: an objet of class ktab
• scannf: a logical value indicating whether the eigenvalues bar plot should be displayed

Details

This function takes 2 ktabs. It does a PTA (partial triadic analysis: pta ) on each ktab, and does a coinertia analysis (coinertia ) on the compromises of the two PTAs.

Returns

a list of class coinertia, subclass dudi. See coinertia

References

Thioulouse J. (2011). Simultaneous analysis of a sequence of paired ecological tables: a comparison of several methods. Annals of Applied Statistics, 5 , 2300-2325.

Author(s)

Jean Thioulouse Jean.Thioulouse@univ-lyon1.fr

WARNING

IMPORTANT : KTX and KTY must have the same k-tables structure, the same number of columns, and the same column weights.

Examples

data(meau)
wit1 <- withinpca(meau$env, meau$design$season, scan = FALSE, scal = "total")
pcaspe <- dudi.pca(meau$spe, scale = FALSE, scan = FALSE, nf = 2)
wit2 <- wca(pcaspe, meau$design$season, scan = FALSE, nf = 2)
kta1 <- ktab.within(wit1, colnames = rep(c("S1","S2","S3","S4","S5","S6"), 4))
kta2 <- ktab.within(wit2, colnames = rep(c("S1","S2","S3","S4","S5","S6"), 4))
costatis1 <- costatis(kta1, kta2, scan = FALSE)
plot(costatis1)