GPoM (version 1.4)

poLabs: Polynomial labels order

Description

Defines the order of the polynomial labels given the number of variables nVar and the maximum polynomial degree dMax.

Usage

poLabs(nVar, dMax, dMin = 0, findIt = NULL, Xnote = "X")

Value

lbls A vector of characters. Each element is the expression of one polynomial term, such as \(X_1^2 X_3 X_4\)

Arguments

nVar

The number of variables

dMax

The maximum degree allowed in the formulation

dMin

The minimum negative degree of the polynomial formulation (0 by default).

findIt

A vector of selected terms.

Xnote

Enables to defines the notation used for the variable, by default Xnote = 'X'.

Author

Sylvain Mangiarotti

See Also

visuEq

Examples

#Regressor order for three variables \eqn{(X1,X2,X3)} (nVar = 3) for a maximum
#polynomial degree equal to 2 (dMax = 2): poLabs(3,2)
#and for two variables only : poLabs(2,2)

# For a quadratic equation of two variables,
# the polynomial \deqn{P(X1,X2) = 0.5 + 0.3 X1 -0.25 X1 X2}
# could thus be written as a vector Pvec such as:
Pvec = c(0.5, 0, 0, 0.3, -0.25, 0)
# considering the convention corresponding to
poLabs(2,2)
# Indeed:
poLabs(2, 2, findIt = Pvec!=0)
# An alternative notation can be used with parameter Xnote
poLabs(2, 2, findIt = Pvec!=0, Xnote = 'w')
# or also
poLabs(2, 2, findIt = Pvec!=0, Xnote = c('x','y'))