class lsst.ts.hexapod.RangedPolynomial(coeffs, min_x, max_x)

Bases: object

A polynomial that is linear outside a specified range.

This model is suitable for systems which are mostly linear, with minor nonlinear corrections. The idea is to prevent unrealistic values outside the range of values over which the polynomial coefficients were fit.

The equation is: ` y(x) = C0 + C1 x + C2 x^2 + ...   for min_x <= x <= max_x y(x) = y(min_y) + C1 (x - min_x)  for x < min_x y(x) = y(max_x) + C1 (x - max_x)  for x > max_x `

coeffs : list [float]

Polynomial coefficients C0, C1, … Must contain at least one element.

min_x : float

Minimum x below which the result is linear.

max_x : float

Maximum x above which the result is linear.


If coeffs has no elements or min_x >= max_x.

Methods Summary

__call__(x) Compute the value of the function.

Methods Documentation


Compute the value of the function.

x : float

Input value.