harmos_signal/

lib.rs

//! Signal processing over plain `&[f64]`: the transform, the reductions, the
//! readings, and the one mergeable accumulator.
//!
//! Every name here is a kernel. Nothing owns your data, nothing is shared,
//! nothing is locked, and nothing is cached: a function takes the slices you
//! already have and answers a value, a `Vec`, or — for anything that *selects*
//! samples — the indices it selected, so the caller reads its own columns.
//! That is the whole design rule, and it is what lets two applications with two
//! different series types share one implementation of the mathematics.
//!
//! This crate depends on `rustfft` and `std`, and on nothing else. It does not
//! depend on `harmos`, and it must not: a runtime's read path stays free of
//! algorithms, and this crate stays liftable into a repository of its own
//! unchanged.
//!
//! This is measurement math and not a data engine. Everything here computes a
//! property of a signal — a spectrum, an envelope, a crossing, a reduction, a
//! calibrated conversion — and nothing here arranges data: tables, joins,
//! group-by, lazy pipelines, generic aggregation frameworks, and columnar
//! containers are a DataFrame's work, which meti left behind to arrive at
//! exactly this content. An application that needs relational row manipulation
//! reaches for a DataFrame of its own, above the runtime's algorithm-free
//! reads.
//!
//! ```
//! use harmos_signal::{Summary, Taper, transform};
//!
//! let rate = 1_000.0;
//! let samples: Vec<f64> = (0..1_000)
//!     .map(|i| (std::f64::consts::TAU * 50.0 * f64::from(i) / rate).sin())
//!     .collect();
//!
//! // The RMS of a unit sine is one over root two, whichever way it is measured.
//! let summary = Summary::of(&samples);
//! assert!((summary.rms().unwrap() - 1.0 / 2.0_f64.sqrt()).abs() < 1e-3);
//!
//! // And the tone reads its own amplitude off the bin it lands on.
//! let spectrum = transform(&samples, rate, Taper::Rectangular);
//! let magnitude = harmos_signal::magnitude(&spectrum.real, &spectrum.imag);
//! assert!((magnitude[50] - 1.0).abs() < 1e-9);
//! ```

mod spectrum;
mod waveform;

pub use spectrum::{
    Band, Decibel, Estimate, Scale, Spectrum, Taper, Welch, band_energy, band_rms, bins, centroid,
    fundamental, harmonics, magnitude, occupied_bandwidth, papr, peaks, phase, reconstruct,
    rolloff, thd, transform,
};
pub use waveform::{
    Edge, Summary, above_floor, crossing, decimate, derivative, edges, extrema, integral, lttb,
    lttb_log, nearest, resample, resample_count, resample_uniform, value_at,
};