Crate efd

This crate implements Elliptical Fourier Descriptor (EFD) and its related functions.

Simple usage of resampling circle:

use efd::Efd;
use ndarray::{stack, Array1, Axis};
use std::f64::consts::TAU;

const N: usize = 10;
let circle = stack![
    Axis(1),
    Array1::linspace(0., TAU, N).mapv(f64::cos),
    Array1::linspace(0., TAU, N).mapv(f64::sin)
];
let curve = circle
    .axis_iter(Axis(0))
    .map(|c| [c[0], c[1]])
    .collect::<Vec<_>>();
let new_curve = Efd::from_curve(&curve, None).generate(20);

Features

This crate support no-std solution via using “libm”, a crate provide pure-rust math functions, please enable it if disabled the “std” feature.

Structs

Efd

Elliptical Fourier Descriptor coefficients. Provide transformation between discrete points and coefficients.

GeoInfo

Geometric information.

Functions

curve_diff

Check the difference between two curves.

fourier_power

Compute the total Fourier power and find the minimum number of harmonics required to exceed the threshold fraction of the total power.

fourier_power_nyq

A convenient function to apply Nyquist Frequency on fourier_power function.