apollon.signal.spectral module

spectral.py (c) Michael Blaß 2016

Provide easy access to frequency spectra obtained by the DFT.

Classes:

_Spectrum_Base Utility class _Spectrum Representation of a frequency spectrum

Functions:

fft Easy to use discrete fourier transform

class apollon.signal.spectral.Spectrogram(inp: numpy.ndarray, fps: int, window: str, n_perseg: int, hop_size: int, n_fft: int = None)

Bases: object

Compute a spectrogram from an one-dimensional input signal.

abs()

Return the magnitude spectrogram.

bins

centroid(power=True)

d_frq

d_time

extract()

flux(subband=False)

fps

frqs

hop_size

inp_size

n_fft

n_overlap

n_perseg

params()

plot(cmap: str = 'nipy_spectral', log_frq: float = None, low: float = None, high: float = None, figsize: tuple = (14, 6), cbar: bool = True) → tuple

Plot the spectrogram in dB scaling. The 0-frequency component is ommitted in plots.

Parameters:

• cmap (str) –
• log_frq (float) – plot it in log domain, centered on log_frq Hz.
• cbar (bool) –
• figsize (tuple) –

Returns:

Tuple (fig, ax)

power()

Return the power spectrogram.

shape

times

window

class apollon.signal.spectral.Spectrum(inp: numpy.ndarray, fps: int, n_fft: int = None, window: str = None)

Bases: apollon.signal.spectral._Spectrum_Base

abs()

Return magnitude spectrum.

centroid(power=True)

extract()

params() → dict

phase()

Return phase spectrum.

power()

Retrun power spectrum.

apollon.signal.spectral.fft(sig, window=None, n_fft=None)

Return the Discrete Fourier Transform for real input.

Params:

sig (array-like) Input time domain signal n_fft (int) FFT length window (str) Name of window function

Returns:(ndarray) FFT bins. Raises:AttributeError

apollon.signal.spectral.stft(inp: numpy.ndarray, fps: int, window: str = 'hanning', n_perseg: int = 512, hop_size: int = None, n_fft: int = None) → apollon.signal.spectral.Spectrogram

Perform Short Time Fourier Transformation of inp

inp is assumed to be an one-dimensional array of real values.

Parameters:

• inp (ndarray) –
• fps (int) –
• window (str) –
• n_perseg (int) –
• hop_size (int) –
• n_fft (int) –

Returns:

(Spectrogram)