inv_poly {flexmet}

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).