spectral_metrics.hpp File Reference

Spectral measurement functions. More...

#include <memory_resource>
#include <tuple>
#include <nk/value/value.hpp>

Go to the source code of this file.

Functions
Value	nk::signal::bandpower (const Value &x, const Value &fs=Value::Empty, const Value &freqrange=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Power in a frequency band (p = bandpower(x, fs, freqrange)).
Value	nk::signal::meanfreq (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Power-weighted mean frequency.
Value	nk::signal::medfreq (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Median frequency.
Value	nk::signal::enbw (const Value &window, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Equivalent noise bandwidth of a window (b = enbw(window, fs)).
std::tuple< Value, Value, Value, Value >	nk::signal::obw (const Value &x, const Value &fs=Value::Empty, double p=0.99, std::pmr::memory_resource *mr=nullptr)
	Occupied bandwidth at fraction p of total power ([bw, flo, fhi, power] = obw(x, fs, p)).
Value	nk::signal::powerbw (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	3-dB power bandwidth around the dominant peak.
Value	nk::signal::spectralcrest (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Spectral crest: max(P) / mean(P) (peakedness).
Value	nk::signal::spectralflatness (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Spectral flatness: geomean(P) / mean(P).
Value	nk::signal::spectralentropy (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Shannon entropy of the normalised PSD.
Value	nk::signal::spectralkurtosis (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Kurtosis of the PSD treated as a frequency distribution.
Value	nk::signal::spectralskewness (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Skewness of the PSD treated as a frequency distribution.
Value	nk::signal::snr (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Signal-to-noise ratio in dB.
Value	nk::signal::sinad (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Signal-to-noise-and-distortion in dB.
Value	nk::signal::thd (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Total harmonic distortion in dB.
Value	nk::signal::sfdr (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Spurious-free dynamic range in dB.
Value	nk::signal::instfreq (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Instantaneous frequency via Hilbert transform.
Value	nk::signal::instbw (const Value &x, const Value &fs=Value::Empty, std::pmr::memory_resource *mr=nullptr)
	Instantaneous bandwidth.

Detailed Description

Spectral measurement functions.

Conventions:

• fs defaults to Value::Empty. With fs.isEmpty() frequencies span [0, π] rad/sample; with fs > 0 they span [0, fs/2] Hz.
• Functions compute the PSD internally via a single-segment periodogram.

Definition in file spectral_metrics.hpp.