pta {ade4}

Partial Triadic Analysis of a K-tables

Description

performs a partial triadic analysis of a K-tables, using an object of class ktab.

Usage

pta(X, scannf = TRUE, nf = 2)
## S3 method for class 'pta'
plot(x, xax = 1, yax = 2, option = 1:4, ...)
## S3 method for class 'pta'
print(x, ...)

Arguments

X

an object of class ktab where the arrays have 1) the same dimensions 2) the same names for columns 3) the same column weightings

scannf

a logical value indicating whether the eigenvalues bar plot should be displayed

nf

if scannf FALSE, an integer indicating the number of kept axes

x

an object of class 'pta'

xax, yax

the numbers of the x-axis and the y-axis

option

an integer between 1 and 4, otherwise the 4 components of the plot are displayed

...

further arguments passed to or from other methods

Value

returns a list of class 'pta', sub-class of 'dudi' containing :

RV

a matrix with the all RV coefficients

RV.eig

a numeric vector with the all eigenvalues (interstructure)

RV.coo

a data frame with the scores of the arrays

tab.names

a vector of characters with the array names

nf

an integer indicating the number of kept axes

rank

an integer indicating the rank of the studied matrix

tabw

a numeric vector with the array weights

cw

a numeric vector with the column weights

lw

a numeric vector with the row weights

eig

a numeric vector with the all eigenvalues (compromis)

cos2

a numeric vector with the \cos^2 between compromise and arrays

tab

a data frame with the modified array

li

a data frame with the row coordinates

l1

a data frame with the row normed scores

co

a data frame with the column coordinates

c1

a data frame with the column normed scores

Tli

a data frame with the row coordinates (each table)

Tco

a data frame with the column coordinates (each table)

Tcomp

a data frame with the principal components (each table)

Tax

a data frame with the principal axes (each table)

TL

a data frame with the factors for Tli

TC

a data frame with the factors for Tco

T4

a data frame with the factors for Tax and Tcomp

Author(s)

Pierre Bady [e-mail]
Anne-Béatrice Dufour [e-mail]

References

Blanc, L., Chessel, D. and Dolédec, S. (1998) Etude de la stabilité temporelle des structures spatiales par Analyse d'une série de tableaux faunistiques totalement appariés. Bulletin Français de la Pêche et de la Pisciculture, 348, 1–21.

Thioulouse, J., and D. Chessel. 1987. Les analyses multi-tableaux en écologie factorielle. I De la typologie d'état à la typologie de fonctionnement par l'analyse triadique. Acta Oecologica, Oecologia Generalis, 8, 463–480.

Examples

data(meaudret)
wit1 <- withinpca(meaudret$env, meaudret$design$season, scan = FALSE, scal = "partial")
kta1 <- ktab.within(wit1, colnames = rep(c("S1", "S2", "S3", "S4", "S5"), 4))
kta2 <- t(kta1)
pta1 <- pta(kta2, scann = FALSE)
pta1
plot(pta1)