ade4 (version 1.01)

dudi: Duality Diagram

Description

as.dudi is called by many functions (pca.dudi, coa.dudi, acm.dudi, ...) and not directly by the user. It creates duality diagrams.

t.dudi returns an object of class 'dudi' where the rows are the columns and the columns are the rows of the initial dudi.

is.dudi returns TRUE if the object is of class dudi

redo.dudi computes again an analysis, eventually changing the number of kept axes. Used by other functions.

Usage

as.dudi(df, col.w, row.w, scannf, nf, call, type, tol = 1e-07, 
    full = FALSE) 
print.dudi(x, ...) 
is.dudi(x) 
redo.dudi(dudi, newnf = 2) 
t.dudi(x)

Arguments

df

a data frame with n rows and p columns

col.w

a numeric vector containing the row weights

row.w

a numeric vector containing the column weights

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

call

generally match.call()

type

a string of characters : the returned list will be of class c(type, "dudi")

tol

a tolerance threshold for null eigenvalues (a value less than tol times the first one is considered as null)

full

a logical value indicating whether all non null eigenvalues should be kept

x, dudi

objects of class dudi

...

further arguments passed to or from other methods

newnf

a data frame

Value

• as.dudi and all the functions that use it return a list with the following components :
• tab
  a data frame with n rows et p columns
• cw
  row weights, a vector with n components
• lw
  columns weights, a vector with p components
• eig
  eigenvalues, a vector with min(n,p) components
• nf
  integer, number of kept axes
• c1
  principal axes, data frame with p rows et nf columns
• l1
  principal componants, data frame with n rows et nf columns
• co
  column coordinates, data frame with p rows et nf columns
• li
  row coordinates, data frame with n rows et nf columns
• call
  original call

References

Escoufier, Y. (1987) The duality diagram : a means of better practical applications In Development in numerical ecology, Legendre, P. & Legendre, L. (Eds.) NATO advanced Institute, Serie G. Springer Verlag, Berlin, 139--156.

Examples

data(deug)
dd1 <- dudi.pca(deug$tab, scannf = FALSE)
dd1
t(dd1)
is.dudi(dd1)
redo.dudi(dd1,3)