Crate poly_interp

A simple but powerful polynomial library focused on interpolation between points. Works with both standard polynomials and parametric curves. Mostly no_std although a dynamic allocator is required.

Structs

PointXY

A point with x and y coordinates.

PointXYT

A point with x, y, and t coordinates. t is usually the independent variable here.

Polynomial

A polynomial function.

XYTCurve

A smooth curve based on functions x(t) and y(t).

Functions

newtons_method

Performs an iterative process to approximate the inverse of a function using its derivative at a given y coordinate. (Solves f(x)=y for x at a given y.) This requires an initial “guess” at the desired x value and a maximum number of iterations to perform when calculating it. The function returns early if it detects that x has been calculated perfectly (function(x) returns exactly y). It may return NaN or infinity if the derivative returns 0 at one of the progressive estimates of x. The function returns (x, f(x)) and not (x, y) if they are different.