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Projections of Supplementary Columns

supcol.Rd

performs projections of supplementary columns.

Usage

supcol(x, ...)
# S3 method for dudi
supcol(x, Xsup, ...) 
# S3 method for coa
supcol(x, Xsup, ...)

Arguments

x

an object used to select a method

Xsup

an array with the supplementary columns (Xsup and x$tab have the same row number)

...

further arguments passed to or from other methods

Details

If supcol.dudi is used, the column vectors of Xsup are projected without prior modification onto the principal components of dudi with the scalar product associated to the row weightings of dudi.

Value

A list of two components:

tabsup

data frame containing the array with the supplementary columns transformed or not

cosup

data frame containing the coordinates of the supplementary projections

Author

Daniel Chessel
Anne-Béatrice Dufour anne-beatrice.dufour@univ-lyon1.fr

Examples

data(rpjdl)
rpjdl.coa <- dudi.coa(rpjdl$fau, scan = FALSE, nf = 4)
rpjdl.coa$co[1:3, ]
#>         Comp1      Comp2       Comp3     Comp4
#> AR  1.3906689 -0.4366455 -0.08999631 0.4036248
#> CP -0.8298783 -0.2134175 -0.99500547 0.8763367
#> ST -0.6045373  0.1035953 -0.68205770 0.4254950
supcol(rpjdl.coa, rpjdl$fau[, 1:3])$cosup  #the same
#>         Comp1      Comp2       Comp3     Comp4
#> AR  1.3906689 -0.4366455 -0.08999631 0.4036248
#> CP -0.8298783 -0.2134175 -0.99500547 0.8763367
#> ST -0.6045373  0.1035953 -0.68205770 0.4254950

data(doubs)
dudi1 <- dudi.pca(doubs$fish, scal = FALSE, scan = FALSE)
if(adegraphicsLoaded()) {
  g1 <- s.arrow(dudi1$co, plot = FALSE)
  g2 <- s.arrow(supcol(dudi1, data.frame(scalewt(doubs$env)))$cosup, plab.cex = 2, plot = FALSE)
  G <- superpose(g1, g2, plot = TRUE)
  
} else {
  s.arrow(dudi1$co)
  s.arrow(supcol(dudi1, data.frame(scalewt(doubs$env)))$cosup, add.p = TRUE, clab = 2)
  symbols(0, 0, circles = 1, inches = FALSE, add = TRUE)
}