spectrogram_plot¶

MATLAB equivalent: sidSpectrogramPlot

spectrogram_plot ¶

Spectrogram colour map plot.

spectrogram_plot ¶

spectrogram_plot(result: SpectrogramResult, *, frequency_scale: str = 'linear', channel: int = 0, clim: tuple | None = None, ax=None) -> dict

Spectrogram colour map plot.

This is the Python port of sidSpectrogramPlot.m.

Plots the spectrogram as a time-frequency colour map with power in dB.

Parameters:

Name	Type	Description	Default
`result`	`SpectrogramResult`	Result struct returned by :func:`sid.spectrogram`.	required
`frequency_scale`	`str`	`'linear'` (default) or `'log'`.	`'linear'`
`channel`	`int`	Zero-based channel index for multi-channel data. Default is `0`.	`0`
`clim`	`tuple of (float, float) or None`	Colour axis limits `(cmin, cmax)` in dB. `None` for automatic scaling (default).	`None`
`ax`	`matplotlib Axes or None`	Existing axes to plot into. If `None`, a new figure is created.	`None`

Returns:

Type	Description
`dict`	Dictionary with the following keys: `'fig'` -- matplotlib Figure handle. `'ax'` -- Axes handle. `'mesh'` -- QuadMesh handle from `pcolormesh`.

Raises:

Type	Description
`SidError`	If result is not a `SpectrogramResult` (code: `'invalid_result'`).
`SidError`	If channel is out of range (code: `'invalid_channel'`).

Examples:

>>> import numpy as np
>>> import sid
>>> Fs = 1000; Ts = 1 / Fs; N = 5000
>>> t = np.arange(N) * Ts
>>> x = np.cos(2 * np.pi * (50 + 100 * t / t[-1]) * t)
>>> result = sid.spectrogram(x, window_length=256, sample_time=Ts)
>>> h = sid.spectrogram_plot(result)

Notes

Specification: SPEC.md S7.5 -- Visualization

The channel parameter is 0-indexed (Python convention), unlike MATLAB's 1-indexed Channel option.