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)