lasp_avpowerspectra.h

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#pragma once
#include "lasp_fft.h"
#include "lasp_mathtypes.h"
#include "lasp_timebuffer.h"
#include "lasp_window.h"
#include <memory>
#include <optional>
 
class PowerSpectra {
public:
  us nfft;
 
private:
  Fft _fft;
 
  vd _window;
  d _scale_fac;
 
public:
  PowerSpectra(const us nfft, const Window::WindowType w);
 
  PowerSpectra(const vd &window);
 
  ccube compute(const dmat &input);
};
 
class AvPowerSpectra {
 
  enum class Mode {
    Averaging = 0,  // Averaging all time date
    Leaking = 1,    // Exponential weighting of an "instantaneous cps"
    Spectrogram = 2 // Instantenous spectrum, no averaging
  };
 
  Mode _mode;
  d _alpha;          // Only valid in case of 'Leaking'
  us n_averages = 0; // Only valid in case of 'Averaging'
 
  PowerSpectra _ps;
  ccube _est;
 
  TimeBuffer _timeBuf;
  us _overlap_keep;
 
public:
  AvPowerSpectra(const us nfft = 2048,
                 const Window::WindowType w = Window::WindowType::Hann,
                 const d overlap_percentage = 50.,
                 const d fs_tau = -1);
 
  AvPowerSpectra(const AvPowerSpectra &) = delete;
  AvPowerSpectra &operator=(const AvPowerSpectra &) = delete;
 
  void reset();
 
  ccube compute(const dmat &timedata);
 
  ccube get_est() const;
 
  us exactOverlapSamples() const { return _ps.nfft - _overlap_keep; }
};