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flexmet (version 1.1)

inv_poly: Polynomial Functions

Description

Evaluate a forward or inverse (monotonic) polynomial function.

Usage

inv_poly(x, coefs, lb = -1000, ub = 1000)

fw_poly(y, coefs)

Arguments

x

Scalar polynomial function input.

coefs

Vector of coefficients that define a monotonic polynomial, see details.

lb

Lower bound of the search interval.

ub

Upper bound of the search interval.

y

Scalar polynomial function output.

Details

$$x = t_0 + t_1y + t_2y^2 + ...$$ Then, for coefs = \((t_0, t_1, t_2, ...)^\prime\), this function finds the corresponding \(y\) value (inv_poly) or \(x\) value (fw_poly).