An S4 class to store partial bootstrap correspondence analysis results.
lengthA numeric vector giving the convex hull maximum
dimension length.
cutoffA length-one numeric vector giving the cutoff value for
samples selection.
keepAn integer vector giving the subscript of the variables
to be kept.
N. Frerebeau
Other classes: 
AoristicSum-class,
CountApportion-class,
EventDate-class,
IncrementTest-class,
MeanDate-class,
PermutationOrder-class,
RateOfChange-class