RangedPolynomial¶

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 

Parameters: coeffs : 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. ValueError If coeffs has no elements or min_x >= max_x.

Methods Summary

 __call__(x) Compute the value of the function.

Methods Documentation

__call__(x)

Compute the value of the function.

Parameters: x : float Input value.