Fuzzy Coding (3-Way)
Usage
flou(a)
Arguments
a
|
real-valued vector, with no missing values.
|
Description
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).Value
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.BACKGROUND
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.References
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
See Also
logique, ca, supplr, supplc.Examples
# 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)