flou {multiv} | R Documentation |
Simple fuzzy, or piecewise linear, coding of a vector: each value in the vector is replaced by a 1 (if it is above or equal to the 67th quantile), by a 0 (if it is below or equal to the 33rd quantile), and by a linearly interpolated value between 0 and 1 (if it lies between the 33rd and 67th quantiles).
flou(a)
a |
real-valued vector, with no missing values. |
matrix of length(a)
rows, and two columns. The first column contains the
fuzzily coded values of a
, and the second column contains their
complements. Hence each row of this returned matrix necessarily sums to 1.
This form of coding is suitable for a subsequent correspondence analysis. When all variable have been fuzzily (or logically) coded, the row masses (proportional to the row sums) are identical.
J.-P. Benzecri Correspondence Analysis Handbook Marcel Dekker, Basel, 1992.
F.J. Gallego, Codage flou en analyse des correspondances, Les Cahiers de l'Analyse des Donnees vol. VII, 413-430, 1982
# Fuzzy coding of input variables, `a', `b', `c': a.fuzz <- flou(a) b.fuzz <- flou(b) c.fuzz <- flou(c) newdata <- cbind(a.fuzz, b.fuzz, c.fuzz) ca.newdata <- ca(newdata)