| dudi.dec {ade4} | R Documentation |
performs a decentred correspondence analysis.
dudi.dec(df, eff, scannf = TRUE, nf = 2)
df |
a data frame containing positive or null values |
eff |
a vector containing the reference distribution. Its length is equal to the number of rows of df |
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 |
Returns a list of class dec and dudi (see dudi) containing also
R |
sum of all the values of the initial table |
Daniel Chessel
Anne B Dufour anne-beatrice.dufour@univ-lyon1.fr
Dolédec, S., Chessel, D. and Olivier J. M. (1995) L'analyse des correspondances décentrée: application aux peuplements ichtyologiques du haut-Rhône. Bulletin Français de la Pêche et de la Pisciculture, 336, 29–40.
data(ichtyo)
dudi1 <- dudi.dec(ichtyo$tab, ichtyo$eff, scan = FALSE)
sum(apply(ichtyo$tab, 2, function(x)
chisq.test(x, p = ichtyo$eff/sum(ichtyo$eff))$statistic))
sum(dudi1$eig) * sum(ichtyo$eff) # the same
s.class(dudi1$li, ichtyo$dat, wt = ichtyo$eff/sum(ichtyo$eff))